Convert.ToInt64 Method

Definition

Converts a specified value to a 64-bit signed integer.

Overloads

ToInt64(Single)

Converts the value of the specified single-precision floating-point number to an equivalent 64-bit signed integer.

ToInt64(String, Int32)

Converts the string representation of a number in a specified base to an equivalent 64-bit signed integer.

ToInt64(String, IFormatProvider)

Converts the specified string representation of a number to an equivalent 64-bit signed integer, using the specified culture-specific formatting information.

ToInt64(Object, IFormatProvider)

Converts the value of the specified object to a 64-bit signed integer, using the specified culture-specific formatting information.

ToInt64(UInt64)

Converts the value of the specified 64-bit unsigned integer to an equivalent 64-bit signed integer.

ToInt64(UInt32)

Converts the value of the specified 32-bit unsigned integer to an equivalent 64-bit signed integer.

ToInt64(UInt16)

Converts the value of the specified 16-bit unsigned integer to the equivalent 64-bit signed integer.

ToInt64(String)

Converts the specified string representation of a number to an equivalent 64-bit signed integer.

ToInt64(SByte)

Converts the value of the specified 8-bit signed integer to the equivalent 64-bit signed integer.

ToInt64(Object)

Converts the value of the specified object to a 64-bit signed integer.

ToInt64(Int64)

Returns the specified 64-bit signed integer; no actual conversion is performed.

ToInt64(Byte)

Converts the value of the specified 8-bit unsigned integer to the equivalent 64-bit signed integer.

ToInt64(Char)

Converts the value of the specified Unicode character to the equivalent 64-bit signed integer.

ToInt64(DateTime)

Calling this method always throws InvalidCastException.

ToInt64(Boolean)

Converts the specified Boolean value to the equivalent 64-bit signed integer.

ToInt64(Double)

Converts the value of the specified double-precision floating-point number to an equivalent 64-bit signed integer.

ToInt64(Int16)

Converts the value of the specified 16-bit signed integer to an equivalent 64-bit signed integer.

ToInt64(Int32)

Converts the value of the specified 32-bit signed integer to an equivalent 64-bit signed integer.

ToInt64(Decimal)

Converts the value of the specified decimal number to an equivalent 64-bit signed integer.

ToInt64(Single)

Converts the value of the specified single-precision floating-point number to an equivalent 64-bit signed integer.

public static long ToInt64 (float value);
Parameters
value
Single

The single-precision floating-point number to convert.

Returns

value, rounded to the nearest 64-bit signed integer. If value is halfway between two whole numbers, the even number is returned; that is, 4.5 is converted to 4, and 5.5 is converted to 6.

Exceptions

value is greater than MaxValue or less than MinValue.

Examples

The following example attempts to convert each element in an array of Single values to a long integer.

float[] values= { Single.MinValue, -1.38e10f, -1023.299f, -12.98f,
                  0f, 9.113e-16f, 103.919f, 17834.191f, Single.MaxValue };
long result;

foreach (float value in values)
{
   try {
      result = Convert.ToInt64(value);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        value.GetType().Name, value, result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("{0} is outside the range of the Int64 type.", value);
   }   
}                                 
// The example displays the following output:
//    -3.40282346638529E+38 is outside the range of the Int64 type.
//    -13799999488 is outside the range of the Int64 type.
//    Converted the Double value -1023.29901123047 to the Int64 value -1023.
//    Converted the Double value -12.9799995422363 to the Int64 value -13.
//    Converted the Double value 0 to the Int64 value 0.
//    Converted the Double value 9.11299983940444E-16 to the Int64 value 0.
//    Converted the Double value 103.918998718262 to the Int64 value 104.
//    Converted the Double value 17834.19140625 to the Int64 value 17834.
//    3.40282346638529E+38 is outside the range of the Int64 type.
Dim values() As Single = { Single.MinValue, -1.38e10, -1023.299, -12.98, _
                           0, 9.113e-16, 103.919, 17834.191, Single.MaxValue }
Dim result As Long

For Each value As Single In values
   Try
      result = Convert.ToInt64(value)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        value.GetType().Name, value, result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("{0} is outside the range of the Int64 type.", value)
   End Try   
Next                                 
' The example displays the following output:
'    -3.40282346638529E+38 is outside the range of the Int64 type.
'    -13799999488 is outside the range of the Int64 type.
'    Converted the Double value -1023.29901123047 to the Int64 value -1023.
'    Converted the Double value -12.9799995422363 to the Int64 value -13.
'    Converted the Double value 0 to the Int64 value 0.
'    Converted the Double value 9.11299983940444E-16 to the Int64 value 0.
'    Converted the Double value 103.918998718262 to the Int64 value 104.
'    Converted the Double value 17834.19140625 to the Int64 value 17834.
'    3.40282346638529E+38 is outside the range of the Int64 type.
See Also

ToInt64(String, Int32)

Converts the string representation of a number in a specified base to an equivalent 64-bit signed integer.

public static long ToInt64 (string value, int fromBase);
Parameters
value
String

A string that contains the number to convert.

fromBase
Int32

The base of the number in value, which must be 2, 8, 10, or 16.

Returns

A 64-bit signed integer that is equivalent to the number in value, or 0 (zero) if value is null.

Exceptions

fromBase is not 2, 8, 10, or 16.

-or-

value, which represents a non-base 10 signed number, is prefixed with a negative sign.

value contains a character that is not a valid digit in the base specified by fromBase. The exception message indicates that there are no digits to convert if the first character in value is invalid; otherwise, the message indicates that value contains invalid trailing characters.

value, which represents a non-base 10 signed number, is prefixed with a negative sign.

-or-

value represents a number that is less than MinValue or greater than MaxValue.

Remarks

If fromBase is 16, you can prefix the number specified by the value parameter with "0x" or "0X".

Because the negative sign is not supported for non-base 10 numeric representations, the ToInt64(String, Int32) method assumes that negative numbers use two’s complement representation. In other words, the method always interprets the highest-order binary bit of a long integer (bit 63) as its sign bit. As a result, it is possible to write code in which a non-base 10 number that is out of the range of the Int64 data type is converted to an Int64 value without the method throwing an exception. The following example converts MaxValue to its hexadecimal string representation, and then calls the ToInt64(String, Int32) method. Instead of throwing an exception, the method displays the message, "0xFFFFFFFFFFFFFFFF converts to -1."

// Create a hexadecimal value out of range of the long type.
string value = ulong.MaxValue.ToString("X");
// Use Convert.ToInt64 to convert it back to a number.
try
{
   long number = Convert.ToInt64(value, 16);
   Console.WriteLine("0x{0} converts to {1}.", value, number);
}   
catch (OverflowException)
{
   Console.WriteLine("Unable to convert '0x{0}' to a long integer.", value);
}   
' Create a hexadecimal value out of range of the Long type.
Dim value As String = ULong.MaxValue.ToString("X")
' Call Convert.ToInt64 to convert it back to a number.
Try
   Dim number As Long = Convert.ToInt64(value, 16)
   Console.WriteLine("0x{0} converts to {1}.", value, number)
Catch e As OverflowException
   Console.WriteLine("Unable to convert '0x{0}' to a long integer.", value)
End Try   

When performing binary operations or numeric conversions, it is always the responsibility of the developer to verify that a method is using the appropriate numeric representation to interpret a particular value. As the following example illustrates, you can ensure that the method handles overflows appropriately by first determining whether a value represents an unsigned or a signed type when converting it to its hexadecimal string representation. Throw an exception if the original value was an unsigned type but the conversion back to an integer yields a value whose sign bit is on.

// Create a negative hexadecimal value out of range of the Byte type.
ulong sourceNumber = ulong.MaxValue;
bool isSigned = Math.Sign(Convert.ToDouble(sourceNumber.GetType().GetField("MinValue").GetValue(null))) == -1;
string value = sourceNumber.ToString("X");
long targetNumber;
try
{
   targetNumber = Convert.ToInt64(value, 16);
   if (! isSigned && ((targetNumber & 0x80000000) != 0))
      throw new OverflowException();
   else 
      Console.WriteLine("0x{0} converts to {1}.", value, targetNumber);
}
catch (OverflowException)
{
   Console.WriteLine("Unable to convert '0x{0}' to a long integer.", value);
} 
// Displays the following to the console:
//    Unable to convert '0xFFFFFFFFFFFFFFFF' to a long integer.     
' Create a negative hexadecimal value out of range of the Long type.
Dim sourceNumber As ULong = ULong.MaxValue
Dim isSigned As Boolean = Math.Sign(sourceNumber.MinValue) = -1
Dim value As String = sourceNumber.ToString("X")
Dim targetNumber As Long
Try
   targetNumber = Convert.ToInt64(value, 16)
   If Not isSigned And ((targetNumber And &H8000000000) <> 0) Then
      Throw New OverflowException()
   Else 
      Console.WriteLine("0x{0} converts to {1}.", value, targetNumber)
   End If    
Catch e As OverflowException
   Console.WriteLine("Unable to convert '0x{0}' to a long integer.", value)
End Try 
' Displays the following to the console:
'    Unable to convert '0xFFFFFFFFFFFFFFFF' to a long integer.     

The following example attempts to interpret each element in a string array as a hexadecimal string and convert it to a long integer.

using System;

public class Example
{
   public static void Main()
   {
      string[] hexStrings = { "8000000000000000", "0FFFFFFFFFFFFFFF", 
                              "f0000000000001000", "00A30", "D", "-13", "GAD" };
      foreach (string hexString in hexStrings)
      {
         try {
            long number = Convert.ToInt64(hexString, 16);
            Console.WriteLine("Converted '{0}' to {1:N0}.", hexString, number);
         }
         catch (FormatException) {
            Console.WriteLine("'{0}' is not in the correct format for a hexadecimal number.",
                              hexString);
         }
         catch (OverflowException) {
            Console.WriteLine("'{0}' is outside the range of an Int64.", hexString);
         }
         catch (ArgumentException) {
            Console.WriteLine("'{0}' is invalid in base 16.", hexString);
         }
      }                                            
   }
}
// The example displays the following output:
//       Converted '8000000000000000' to -9,223,372,036,854,775,808.
//       Converted '0FFFFFFFFFFFFFFF' to 1,152,921,504,606,846,975.
//       'f0000000000001000' is outside the range of an Int64.
//       Converted '00A30' to 2,608.
//       Converted 'D' to 13.
//       '-13' is invalid in base 16.
//       'GAD' is not in the correct format for a hexadecimal number.
Module Example
   Public Sub Main()
      Dim hexStrings() As String = { "8000000000000000", "0FFFFFFFFFFFFFFF", _
                                     "f0000000000001000", "00A30", "D", "-13", "GAD" }
      For Each hexString As String In hexStrings
         Try
            Dim number As Long = Convert.ToInt64(hexString, 16)
            Console.WriteLine("Converted '{0}' to {1:N0}.", hexString, number)
         Catch e As FormatException
            Console.WriteLine("'{0}' is not in the correct format for a hexadecimal number.", _
                              hexString)
         Catch e As OverflowException
            Console.WriteLine("'{0}' is outside the range of an Int64.", hexString)
         Catch e As ArgumentException
            Console.WriteLine("'{0}' is invalid in base 16.", hexString)
         End Try
      Next                                            
   End Sub
End Module
' The example displays the following output:
'       Converted '8000000000000000' to -9,223,372,036,854,775,808.
'       Converted '0FFFFFFFFFFFFFFF' to 1,152,921,504,606,846,975.
'       'f0000000000001000' is outside the range of an Int64.
'       Converted '00A30' to 2,608.
'       Converted 'D' to 13.
'       '-13' is invalid in base 16.
'       'GAD' is not in the correct format for a hexadecimal number.

ToInt64(String, IFormatProvider)

Converts the specified string representation of a number to an equivalent 64-bit signed integer, using the specified culture-specific formatting information.

public static long ToInt64 (string value, IFormatProvider provider);
Parameters
value
String

A string that contains the number to convert.

provider
IFormatProvider

An object that supplies culture-specific formatting information.

Returns

A 64-bit signed integer that is equivalent to the number in value, or 0 (zero) if value is null.

Exceptions

value does not consist of an optional sign followed by a sequence of digits (0 through 9).

value represents a number that is less than MinValue or greater than MaxValue.

Examples

The following example defines a custom NumberFormatInfo object that recognizes the string "pos" as the positive sign and the string "neg" as the negative sign. It then attempts to convert each element of a numeric string array to an integer using both this provider and the NumberFormatInfo provider for the invariant culture.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      // Create a NumberFormatInfo object and set the properties that
      // affect conversions using Convert.ToInt64(String, IFormatProvider).
      NumberFormatInfo customProvider = new NumberFormatInfo();
      customProvider.NegativeSign = "neg ";
      customProvider.PositiveSign = "pos ";

      // Create an array of providers with the custom provider and the
      // NumberFormatInfo object for the invariant culture.
      NumberFormatInfo[] providers = { customProvider,
                                       NumberFormatInfo.InvariantInfo };
      
      // Define an array of strings to parse.
      string[] numericStrings = { "123456789", "+123456789", "pos 123456789", 
                                  "-123456789", "neg 123456789", "123456789.",
                                  "123,456,789", "(123456789)",
                                  "9223372036854775808", "-9223372036854775809" };

      for (int ctr = 0; ctr < 2; ctr++)
      {
         IFormatProvider provider = providers[ctr];
         Console.WriteLine(ctr == 0 ? "Custom Provider:" : "Invariant Culture:");
         foreach (string numericString in numericStrings)
         {
            Console.Write("   {0,-22} -->  ", numericString);
            try {
               Console.WriteLine("{0,22}", Convert.ToInt32(numericString, provider));
            }
            catch (FormatException) {
               Console.WriteLine("{0,22}", "Unrecognized Format");
            }   
            catch (OverflowException) {
               Console.WriteLine("{0,22}", "Overflow");
            }
         }
         Console.WriteLine();
      }
   }
}
// The example displays the following output:
//       Custom Provider:
//          123456789              -->               123456789
//          +123456789             -->     Unrecognized Format
//          pos 123456789          -->               123456789
//          -123456789             -->     Unrecognized Format
//          neg 123456789          -->              -123456789
//          123456789.             -->     Unrecognized Format
//          123,456,789            -->     Unrecognized Format
//          (123456789)            -->     Unrecognized Format
//          9223372036854775808    -->                Overflow
//          -9223372036854775809   -->     Unrecognized Format
//       
//       Invariant Culture:
//          123456789              -->               123456789
//          +123456789             -->               123456789
//          pos 123456789          -->     Unrecognized Format
//          -123456789             -->              -123456789
//          neg 123456789          -->     Unrecognized Format
//          123456789.             -->     Unrecognized Format
//          123,456,789            -->     Unrecognized Format
//          (123456789)            -->     Unrecognized Format
//          9223372036854775808    -->                Overflow
//          -9223372036854775809   -->                Overflow
Imports System.Globalization

Public Module Example
   Public Sub Main()
      ' Create a NumberFormatInfo object and set the properties that
      ' affect conversions using Convert.ToInt64(String, IFormatProvider).
      Dim customProvider As New NumberFormatInfo()
      customProvider.NegativeSign = "neg "
      customProvider.PositiveSign = "pos "

      ' Create an array of providers with the custom provider and the
      ' NumberFormatInfo object for the invariant culture.
      Dim providers() As NumberFormatInfo = {customProvider, _
                                             NumberFormatInfo.InvariantInfo }
      
      ' Define an array of strings to parse.
      Dim numericStrings() As String = { "123456789", "+123456789", _
                                         "pos 123456789", "-123456789", _
                                         "neg 123456789", "123456789.", _
                                         "123,456,789", "(123456789)", _
                                         "9223372036854775808", "-9223372036854775809" }

      For ctr As Integer = 0 to 1
         Dim provider As IFormatProvider = providers(ctr)
         Console.WriteLine(IIf(ctr = 0, "Custom Provider:", "Invariant Culture:"))
         For Each numericString As String In numericStrings
            Console.Write("   {0,-22} -->  ", numericString)
            Try
               Console.WriteLine("{0,22}", Convert.ToInt32(numericString, provider))
            Catch e As FormatException
               Console.WriteLine("{0,22}", "Unrecognized Format")
            Catch e As OverflowException
               Console.WriteLine("{0,22}", "Overflow")
            End Try
         Next
         Console.WriteLine()
      Next
   End Sub 
End Module 
' The example displays the following output:
'       Custom Provider:
'          123456789              -->               123456789
'          +123456789             -->     Unrecognized Format
'          pos 123456789          -->               123456789
'          -123456789             -->     Unrecognized Format
'          neg 123456789          -->              -123456789
'          123456789.             -->     Unrecognized Format
'          123,456,789            -->     Unrecognized Format
'          (123456789)            -->     Unrecognized Format
'          9223372036854775808    -->                Overflow
'          -9223372036854775809   -->     Unrecognized Format
'       
'       Invariant Culture:
'          123456789              -->               123456789
'          +123456789             -->               123456789
'          pos 123456789          -->     Unrecognized Format
'          -123456789             -->              -123456789
'          neg 123456789          -->     Unrecognized Format
'          123456789.             -->     Unrecognized Format
'          123,456,789            -->     Unrecognized Format
'          (123456789)            -->     Unrecognized Format
'          9223372036854775808    -->                Overflow
'          -9223372036854775809   -->                Overflow

Remarks

The return value is the result of invoking the Int64.Parse method on value.

provider is an IFormatProvider instance that obtains a NumberFormatInfo object. The NumberFormatInfo object provides culture-specific information about the format of value. If provider is null, the NumberFormatInfo for the current culture is used.

If you prefer not to handle an exception if the conversion fails, you can call the Int64.TryParse method instead. It returns a Boolean value that indicates whether the conversion succeeded or failed.

ToInt64(Object, IFormatProvider)

Converts the value of the specified object to a 64-bit signed integer, using the specified culture-specific formatting information.

public static long ToInt64 (object value, IFormatProvider provider);
Parameters
value
Object

An object that implements the IConvertible interface.

provider
IFormatProvider

An object that supplies culture-specific formatting information.

Returns

A 64-bit signed integer that is equivalent to value, or zero if value is null.

Exceptions

value is not in an appropriate format.

value does not implement the IConvertible interface.

-or-

The conversion is not supported.

value represents a number that is less than MinValue or greater than MaxValue.

Examples

The following example defines a class that implements IConvertible and a class that implements IFormatProvider. Objects of the class that implements IConvertible hold an array of Double values. An object of each class is passed to the ToInt64 method. This method returns an average of the array of Double values, using the object that implements IFormatProvider to determine how to calculate the average.

using namespace System;
using namespace System::Collections;

// Define the types of averaging available in the class 
// implementing IConvertible.
public enum class AverageType : short
{
   None = 0,
   GeometricMean = 1,
   ArithmeticMean = 2,
   Median = 3
};


// Pass an instance of this class to methods that require an 
// IFormatProvider. The class instance determines the type of 
// average to calculate.
ref class AverageInfo: public IFormatProvider
{
protected:
   AverageType AvgType;

public:

   // Specify the type of averaging in the constructor.
   AverageInfo( AverageType avgType )
   {
      this->AvgType = avgType;
   }


   // This method returns a reference to the containing object 
   // if an object of AverageInfo type is requested. 
   virtual Object^ GetFormat( Type^ argType )
   {
      if ( argType == AverageInfo::typeid)
            return this;
      else
            return (Object^)0;
   }


   property AverageType TypeOfAverage 
   {

      // Use this property to set or get the type of averaging.
      AverageType get()
      {
         return this->AvgType;
      }

      void set( AverageType value )
      {
         this->AvgType = value;
      }

   }

};


// This class encapsulates an array of double values and implements 
// the IConvertible interface. Most of the IConvertible methods 
// return an average of the array elements in one of three types: 
// arithmetic mean, geometric mean, or median. 
ref class DataSet: public IConvertible
{
private:
   static Object^ null = nullptr;

protected:
   ArrayList^ data;
   AverageInfo^ defaultProvider;

   // This method unboxes a boxed double.
   double UnBoxDouble( Object^ obj )
   {
      return  *static_cast<double^>(obj);
   }


public:

   // Construct the object and add an initial list of values.
   // Create a default format provider.
   DataSet( ... array<Double>^values )
   {
      data = gcnew ArrayList( (Array^)values );
      defaultProvider = gcnew AverageInfo( AverageType::ArithmeticMean );
   }


   // Add additional values with this method.
   int Add( double value )
   {
      data->Add( value );
      return data->Count;
   }


   property double Item[ int ]
   {

      // Get, set, and add values with this indexer property.
      double get( int index )
      {
         if ( index >= 0 && index < data->Count )
                  return UnBoxDouble( data[ index ] );
         else
                  throw gcnew InvalidOperationException( "[DataSet.get] Index out of range." );
      }

      void set( int index, double value )
      {
         if ( index >= 0 && index < data->Count )
                  data[ index ] = value;
         else
         if ( index == data->Count )
                  data->Add( value );
         else
                  throw gcnew InvalidOperationException( "[DataSet.set] Index out of range." );
      }

   }

   property int Count 
   {

      // This property returns the number of elements in the object.
      int get()
      {
         return data->Count;
      }

   }

protected:

   // This method calculates the average of the object's elements.
   double Average( AverageType avgType )
   {
      double SumProd;
      if ( data->Count == 0 )
            return 0.0;

      switch ( avgType )
      {
         case AverageType::GeometricMean:
            SumProd = 1.0;
            for ( int Index = 0; Index < data->Count; Index++ )
               SumProd *= UnBoxDouble( data[ Index ] );
            
            // This calculation will not fail with negative 
            // elements.
            return Math::Sign( SumProd ) * Math::Pow( Math::Abs( SumProd ), 1.0 / data->Count );

         case AverageType::ArithmeticMean:
            SumProd = 0.0;
            for ( int Index = 0; Index < data->Count; Index++ )
               SumProd += UnBoxDouble( data[ Index ] );
            return SumProd / data->Count;

         case AverageType::Median:
            if ( data->Count % 2 == 0 )
                        return (UnBoxDouble( data[ data->Count / 2 ] ) + UnBoxDouble( data[ data->Count / 2 - 1 ] )) / 2.0;
            else
                        return UnBoxDouble( data[ data->Count / 2 ] );

         default:
            return 0.0;
      }
   }


   // Get the AverageInfo object from the caller's format provider,
   // or use the local default.
   AverageInfo^ GetAverageInfo( IFormatProvider^ provider )
   {
      AverageInfo^ avgInfo = nullptr;
      if ( provider != nullptr )
            avgInfo = static_cast<AverageInfo^>(provider->GetFormat( AverageInfo::typeid ));

      if ( avgInfo == nullptr )
            return defaultProvider;
      else
            return avgInfo;
   }


   // Calculate the average and limit the range.
   double CalcNLimitAverage( double min, double max, IFormatProvider^ provider )
   {
      
      // Get the format provider and calculate the average.
      AverageInfo^ avgInfo = GetAverageInfo( provider );
      double avg = Average( avgInfo->TypeOfAverage );
      
      // Limit the range, based on the minimum and maximum values 
      // for the type.
      return avg > max ? max : avg < min ? min : avg;
   }


public:

   // The following elements are required by IConvertible.
   // None of these conversion functions throw exceptions. When
   // the data is out of range for the type, the appropriate
   // MinValue or MaxValue is used.
   virtual TypeCode GetTypeCode()
   {
      return TypeCode::Object;
   }

   virtual bool ToBoolean( IFormatProvider^ provider )
   {
      
      // ToBoolean is false if the dataset is empty.
      if ( data->Count <= 0 )
            return false;
      // For median averaging, ToBoolean is true if any 
      // non-discarded elements are nonzero.
      else
      
      // For median averaging, ToBoolean is true if any 
      // non-discarded elements are nonzero.
      if ( AverageType::Median == GetAverageInfo( provider )->TypeOfAverage )
      {
         if ( data->Count % 2 == 0 )
                  return (UnBoxDouble( data[ data->Count / 2 ] ) != 0.0 || UnBoxDouble( data[ data->Count / 2 - 1 ] ) != 0.0);
         else
                  return UnBoxDouble( data[ data->Count / 2 ] ) != 0.0;
      }
      // For arithmetic or geometric mean averaging, ToBoolean is 
      // true if any element of the dataset is nonzero.  
      else
      {
         for ( int Index = 0; Index < data->Count; Index++ )
            if ( UnBoxDouble( data[ Index ] ) != 0.0 )
                        return true;
         return false;
      }
   }

   virtual Byte ToByte( IFormatProvider^ provider )
   {
      return Convert::ToByte( CalcNLimitAverage( Byte::MinValue, Byte::MaxValue, provider ) );
   }

   virtual Char ToChar( IFormatProvider^ provider )
   {
      return Convert::ToChar( Convert::ToUInt16( CalcNLimitAverage( Char::MinValue, Char::MaxValue, provider ) ) );
   }


   // Convert to DateTime by adding the calculated average as 
   // seconds to the current date and time. A valid DateTime is 
   // always returned.
   virtual DateTime ToDateTime( IFormatProvider^ provider )
   {
      double seconds = Average( GetAverageInfo( provider )->TypeOfAverage );
      try
      {
         return DateTime::Now.AddSeconds( seconds );
      }
      catch ( ArgumentOutOfRangeException^ ) 
      {
         return seconds < 0.0 ? DateTime::MinValue : DateTime::MaxValue;
      }

   }

   virtual Decimal ToDecimal( IFormatProvider^ provider )
   {
      
      // The Double conversion rounds Decimal.MinValue and 
      // Decimal.MaxValue to invalid Decimal values, so the 
      // following limits must be used.
      return Convert::ToDecimal( CalcNLimitAverage(  -79228162514264330000000000000.0, 79228162514264330000000000000.0, provider ) );
   }

   virtual double ToDouble( IFormatProvider^ provider )
   {
      return Average( GetAverageInfo( provider )->TypeOfAverage );
   }

   virtual short ToInt16( IFormatProvider^ provider )
   {
      return Convert::ToInt16( CalcNLimitAverage( Int16::MinValue, Int16::MaxValue, provider ) );
   }

   virtual int ToInt32( IFormatProvider^ provider )
   {
      return Convert::ToInt32( CalcNLimitAverage( Int32::MinValue, Int32::MaxValue, provider ) );
   }

   virtual __int64 ToInt64( IFormatProvider^ provider )
   {
      
      // The Double conversion rounds Int64.MinValue and 
      // Int64.MaxValue to invalid Int64 values, so the following 
      // limits must be used.
      return Convert::ToInt64( CalcNLimitAverage(  -9223372036854775000, 9223372036854775000, provider ) );
   }

   virtual signed char ToSByte( IFormatProvider^ provider )
   {
      return Convert::ToSByte( CalcNLimitAverage( SByte::MinValue, SByte::MaxValue, provider ) );
   }

   virtual float ToSingle( IFormatProvider^ provider )
   {
      return Convert::ToSingle( CalcNLimitAverage( Single::MinValue, Single::MaxValue, provider ) );
   }

   virtual UInt16 ToUInt16( IFormatProvider^ provider )
   {
      return Convert::ToUInt16( CalcNLimitAverage( UInt16::MinValue, UInt16::MaxValue, provider ) );
   }

   virtual UInt32 ToUInt32( IFormatProvider^ provider )
   {
      return Convert::ToUInt32( CalcNLimitAverage( UInt32::MinValue, UInt32::MaxValue, provider ) );
   }

   virtual UInt64 ToUInt64( IFormatProvider^ provider )
   {
      
      // The Double conversion rounds UInt64.MaxValue to an invalid
      // UInt64 value, so the following limit must be used.
      return Convert::ToUInt64( CalcNLimitAverage( 0, 18446744073709550000.0, provider ) );
   }

   virtual Object^ ToType( Type^ conversionType, IFormatProvider^ provider )
   {
      return Convert::ChangeType( Average( GetAverageInfo( provider )->TypeOfAverage ), conversionType );
   }

   virtual String^ ToString( IFormatProvider^ provider )
   {
      AverageType avgType = GetAverageInfo( provider )->TypeOfAverage;
      return String::Format( "( {0}: {1:G10} )", avgType, Average( avgType ) );
   }

};


// Display a DataSet with three different format providers.
void DisplayDataSet( DataSet^ ds )
{
   IFormatProvider^ null = nullptr;
   String^ fmt = "{0,-12}{1,20}{2,20}{3,20}";
   AverageInfo^ median = gcnew AverageInfo( AverageType::Median );
   AverageInfo^ geMean = gcnew AverageInfo( AverageType::GeometricMean );
   
   // Display the dataset elements.
   if ( ds->Count > 0 )
   {
      Console::Write( "\nDataSet: [{0}", ds->Item[ 0 ] );
      for ( int iX = 1; iX < ds->Count; iX++ )
         Console::Write( ", {0}", ds->Item[ iX ] );
      Console::WriteLine( "]\n" );
   }

   Console::WriteLine( fmt, "Convert::", "Default", "Geometric Mean", "Median" );
   Console::WriteLine( fmt, "---------", "-------", "--------------", "------" );
   Console::WriteLine( fmt, "ToBoolean", Convert::ToBoolean( ds, null ), Convert::ToBoolean( ds, geMean ), Convert::ToBoolean( ds, median ) );
   Console::WriteLine( fmt, "ToByte", Convert::ToByte( ds, null ), Convert::ToByte( ds, geMean ), Convert::ToByte( ds, median ) );
   Console::WriteLine( fmt, "ToChar", Convert::ToChar( ds, null ), Convert::ToChar( ds, geMean ), Convert::ToChar( ds, median ) );
   Console::WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}"
   "{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}", "ToDateTime", Convert::ToDateTime( ds, null ), Convert::ToDateTime( ds, geMean ), Convert::ToDateTime( ds, median ) );
   Console::WriteLine( fmt, "ToDecimal", Convert::ToDecimal( ds, null ), Convert::ToDecimal( ds, geMean ), Convert::ToDecimal( ds, median ) );
   Console::WriteLine( fmt, "ToDouble", Convert::ToDouble( ds, null ), Convert::ToDouble( ds, geMean ), Convert::ToDouble( ds, median ) );
   Console::WriteLine( fmt, "ToInt16", Convert::ToInt16( ds, null ), Convert::ToInt16( ds, geMean ), Convert::ToInt16( ds, median ) );
   Console::WriteLine( fmt, "ToInt32", Convert::ToInt32( ds, null ), Convert::ToInt32( ds, geMean ), Convert::ToInt32( ds, median ) );
   Console::WriteLine( fmt, "ToInt64", Convert::ToInt64( ds, null ), Convert::ToInt64( ds, geMean ), Convert::ToInt64( ds, median ) );
   Console::WriteLine( fmt, "ToSByte", Convert::ToSByte( ds, null ), Convert::ToSByte( ds, geMean ), Convert::ToSByte( ds, median ) );
   Console::WriteLine( fmt, "ToSingle", Convert::ToSingle( ds, null ), Convert::ToSingle( ds, geMean ), Convert::ToSingle( ds, median ) );
   Console::WriteLine( fmt, "ToUInt16", Convert::ToUInt16( ds, null ), Convert::ToUInt16( ds, geMean ), Convert::ToUInt16( ds, median ) );
   Console::WriteLine( fmt, "ToUInt32", Convert::ToUInt32( ds, null ), Convert::ToUInt32( ds, geMean ), Convert::ToUInt32( ds, median ) );
   Console::WriteLine( fmt, "ToUInt64", Convert::ToUInt64( ds, null ), Convert::ToUInt64( ds, geMean ), Convert::ToUInt64( ds, median ) );
}

int main()
{
   Console::WriteLine( "This example of the "
   "Convert::To<Type>( Object*, IFormatProvider* ) methods "
   "\ngenerates the following output. The example "
   "displays the values \nreturned by the methods, "
   "using several IFormatProvider objects.\n" );
   
   // To call a [ParamArray] method in C++, you cannot just
   // list the parameters, you need to build an array.
   array<Double>^dataElem = gcnew array<Double>(6);
   dataElem[ 0 ] = 10.5;
   dataElem[ 1 ] = 22.2;
   dataElem[ 2 ] = 45.9;
   dataElem[ 3 ] = 88.7;
   dataElem[ 4 ] = 156.05;
   dataElem[ 5 ] = 297.6;
   DataSet^ ds1 = gcnew DataSet( dataElem );
   DisplayDataSet( ds1 );
   dataElem = gcnew array<Double>(5);
   dataElem[ 0 ] = 359999.95;
   dataElem[ 1 ] = 425000;
   dataElem[ 2 ] = 499999.5;
   dataElem[ 3 ] = 775000;
   dataElem[ 4 ] = 1695000;
   DataSet^ ds2 = gcnew DataSet( dataElem );
   DisplayDataSet( ds2 );
}

/*
This example of the Convert::To<Type>( Object*, IFormatProvider* ) methods
generates the following output. The example displays the values
returned by the methods, using several IFormatProvider objects.

DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]

Convert::                Default      Geometric Mean              Median
---------                -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       103                  59                  67
ToChar                         g                   ;                   C
ToDateTime   2003-05-13 15:30:23 2003-05-13 15:29:39 2003-05-13 15:29:47
ToDecimal       103.491666666667    59.4332135445164                67.3
ToDouble        103.491666666667    59.4332135445164                67.3
ToInt16                      103                  59                  67
ToInt32                      103                  59                  67
ToInt64                      103                  59                  67
ToSByte                      103                  59                  67
ToSingle                103.4917            59.43321                67.3
ToUInt16                     103                  59                  67
ToUInt32                     103                  59                  67
ToUInt64                     103                  59                  67

DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]

Convert::                Default      Geometric Mean              Median
---------                -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       255                 255                 255
ToChar                         ?                   ?                   ?
ToDateTime   2003-05-22 08:05:19 2003-05-20 22:54:57 2003-05-19 10:21:59
ToDecimal              750999.89    631577.237188435            499999.5
ToDouble               750999.89    631577.237188435            499999.5
ToInt16                    32767               32767               32767
ToInt32                   751000              631577              500000
ToInt64                   751000              631577              500000
ToSByte                      127                 127                 127
ToSingle                750999.9            631577.3            499999.5
ToUInt16                   65535               65535               65535
ToUInt32                  751000              631577              500000
ToUInt64                  751000              631577              500000
*/
using System;
using System.Collections;

// Define the types of averaging available in the class 
// implementing IConvertible.
public enum AverageType : short
{
    None = 0,
    GeometricMean = 1,
    ArithmeticMean = 2,
    Median = 3
};

// Pass an instance of this class to methods that require an 
// IFormatProvider. The class instance determines the type of 
// average to calculate.
public class AverageInfo : IFormatProvider
{
    protected AverageType AvgType;

    // Specify the type of averaging in the constructor.
    public AverageInfo( AverageType avgType )
    {
        this.AvgType = avgType;
    }

    // This method returns a reference to the containing object 
    // if an object of AverageInfo type is requested. 
    public object GetFormat( Type argType )
    {
        if ( argType == typeof( AverageInfo ) )
            return this;
        else
            return null;
    }

    // Use this property to set or get the type of averaging.
    public AverageType TypeOfAverage        
    {
        get { return this.AvgType; }
        set { this.AvgType = value; }
    }
}

// This class encapsulates an array of double values and implements 
// the IConvertible interface. Most of the IConvertible methods 
// return an average of the array elements in one of three types: 
// arithmetic mean, geometric mean, or median. 
public class DataSet : IConvertible
{
    protected ArrayList     data;
    protected AverageInfo   defaultProvider;
        
    // Construct the object and add an initial list of values.
    // Create a default format provider.
    public DataSet( params double[ ] values )
    {
        data = new ArrayList( values );
        defaultProvider = 
            new AverageInfo( AverageType.ArithmeticMean );
    }
        
    // Add additional values with this method.
    public int Add( double value )
    {
        data.Add( value );
        return data.Count;
    }
        
    // Get, set, and add values with this indexer property.
    public double this[ int index ]        
    {
        get
        {
            if( index >= 0 && index < data.Count )
                return (double)data[ index ];
            else
                throw new InvalidOperationException(
                    "[DataSet.get] Index out of range." );
        }
        set
        {
            if( index >= 0 && index < data.Count )
                data[ index ] = value;

            else if( index == data.Count )
                data.Add( value );
            else
                throw new InvalidOperationException(
                    "[DataSet.set] Index out of range." );
        }
    }
        
    // This property returns the number of elements in the object.
    public int Count        
    {
        get { return data.Count; }
    }

    // This method calculates the average of the object's elements.
    protected double Average( AverageType avgType )
    {
        double  SumProd;

        if( data.Count == 0 ) 
            return 0.0;

        switch( avgType )
        {
            case AverageType.GeometricMean:

                SumProd = 1.0;
                for( int Index = 0; Index < data.Count; Index++ )
                    SumProd *= (double)data[ Index ];
                
                // This calculation will not fail with negative 
                // elements.
                return Math.Sign( SumProd ) * Math.Pow( 
                    Math.Abs( SumProd ), 1.0 / data.Count );

            case AverageType.ArithmeticMean:

                SumProd = 0.0;
                for( int Index = 0; Index < data.Count; Index++ )
                    SumProd += (double)data[ Index ];

                return SumProd / data.Count;

            case AverageType.Median:

                if( data.Count % 2 == 0 )
                    return ( (double)data[ data.Count / 2 ] + 
                        (double)data[ data.Count / 2 - 1 ] ) / 2.0;
                else
                    return (double)data[ data.Count / 2 ];

            default:
                return 0.0;
        }
    }

    // Get the AverageInfo object from the caller's format provider,
    // or use the local default.
    protected AverageInfo GetAverageInfo( IFormatProvider provider )
    {
        AverageInfo avgInfo = null;

        if( provider != null )
            avgInfo = (AverageInfo)provider.GetFormat( 
                typeof( AverageInfo ) );

        if ( avgInfo == null )
            return defaultProvider;
        else
            return avgInfo;
    }

    // Calculate the average and limit the range.
    protected double CalcNLimitAverage( double min, double max, 
        IFormatProvider provider )
    {
        // Get the format provider and calculate the average.
        AverageInfo avgInfo = GetAverageInfo( provider );
        double avg = Average( avgInfo.TypeOfAverage );

        // Limit the range, based on the minimum and maximum values 
        // for the type.
        return avg > max ? max : avg < min ? min : avg;

    }

    // The following elements are required by IConvertible.

    // None of these conversion functions throw exceptions. When
    // the data is out of range for the type, the appropriate
    // MinValue or MaxValue is used.
    public TypeCode GetTypeCode( )
    {
        return TypeCode.Object;
    }

    public bool ToBoolean( IFormatProvider provider )
    {
        // ToBoolean is false if the dataset is empty.
        if( data.Count <= 0 )
            return false;

        // For median averaging, ToBoolean is true if any 
        // non-discarded elements are nonzero.
        else if( AverageType.Median == 
            GetAverageInfo( provider ).TypeOfAverage )
        {
            if (data.Count % 2 == 0 )
                return ( (double)data[ data.Count / 2 ] != 0.0 || 
                    (double)data[ data.Count / 2 - 1 ] != 0.0 );
            else
                return (double)data[ data.Count / 2 ] != 0.0;
        }

        // For arithmetic or geometric mean averaging, ToBoolean is 
        // true if any element of the dataset is nonzero.  
        else
        {
            for( int Index = 0; Index < data.Count; Index++ )
                if( (double)data[ Index ] != 0.0 ) 
                    return true;
            return false;
        }
    }

    public byte ToByte( IFormatProvider provider )
    {
        return Convert.ToByte( CalcNLimitAverage( 
            Byte.MinValue, Byte.MaxValue, provider ) );
    }

    public char ToChar( IFormatProvider provider )
    {
        return Convert.ToChar( Convert.ToUInt16( CalcNLimitAverage( 
            Char.MinValue, Char.MaxValue, provider ) ) );
    }

    // Convert to DateTime by adding the calculated average as 
    // seconds to the current date and time. A valid DateTime is 
    // always returned.
    public DateTime ToDateTime( IFormatProvider provider )
    {
        double seconds = 
            Average( GetAverageInfo( provider ).TypeOfAverage );
        try
        {
            return DateTime.Now.AddSeconds( seconds );
        }
        catch( ArgumentOutOfRangeException )
        {
            return seconds < 0.0 ? DateTime.MinValue : DateTime.MaxValue;
        }
    }

    public decimal ToDecimal( IFormatProvider provider )
    {
        // The Double conversion rounds Decimal.MinValue and 
        // Decimal.MaxValue to invalid Decimal values, so the 
        // following limits must be used.
        return Convert.ToDecimal( CalcNLimitAverage( 
            -79228162514264330000000000000.0, 
            79228162514264330000000000000.0, provider ) );
    }

    public double ToDouble( IFormatProvider provider )
    {
        return Average( GetAverageInfo(provider).TypeOfAverage );
    }

    public short ToInt16( IFormatProvider provider )
    {
        return Convert.ToInt16( CalcNLimitAverage( 
            Int16.MinValue, Int16.MaxValue, provider ) );
    }

    public int ToInt32( IFormatProvider provider )
    {
        return Convert.ToInt32( CalcNLimitAverage( 
            Int32.MinValue, Int32.MaxValue, provider ) );
    }

    public long ToInt64( IFormatProvider provider )
    {
        // The Double conversion rounds Int64.MinValue and 
        // Int64.MaxValue to invalid Int64 values, so the following 
        // limits must be used.
        return Convert.ToInt64( CalcNLimitAverage( 
            -9223372036854775000, 9223372036854775000, provider ) );
    }

    public SByte ToSByte( IFormatProvider provider )
    {
        return Convert.ToSByte( CalcNLimitAverage( 
            SByte.MinValue, SByte.MaxValue, provider ) );
    }

    public float ToSingle( IFormatProvider provider )
    {
        return Convert.ToSingle( CalcNLimitAverage( 
            Single.MinValue, Single.MaxValue, provider ) );
    }

    public UInt16 ToUInt16( IFormatProvider provider )
    {
        return Convert.ToUInt16( CalcNLimitAverage( 
            UInt16.MinValue, UInt16.MaxValue, provider ) );
    }

    public UInt32 ToUInt32( IFormatProvider provider )
    {
        return Convert.ToUInt32( CalcNLimitAverage( 
            UInt32.MinValue, UInt32.MaxValue, provider ) );
    }

    public UInt64 ToUInt64( IFormatProvider provider )
    {
        // The Double conversion rounds UInt64.MaxValue to an invalid
        // UInt64 value, so the following limit must be used.
        return Convert.ToUInt64( CalcNLimitAverage( 
            0, 18446744073709550000.0, provider ) );
    }

    public object ToType( Type conversionType, 
        IFormatProvider provider )
    {
        return Convert.ChangeType( Average( 
            GetAverageInfo( provider ).TypeOfAverage ), 
            conversionType );
    }

    public string ToString( IFormatProvider provider )
    {
        AverageType avgType = GetAverageInfo( provider ).TypeOfAverage;
        return String.Format( "( {0}: {1:G10} )", avgType, 
            Average( avgType ) );
    }
}
   
class IConvertibleProviderDemo
{
    // Display a DataSet with three different format providers.
    public static void DisplayDataSet( DataSet ds )
    {
        string      fmt    = "{0,-12}{1,20}{2,20}{3,20}";
        AverageInfo median = new AverageInfo( AverageType.Median );
        AverageInfo geMean = 
            new AverageInfo( AverageType.GeometricMean );

         // Display the dataset elements.
        if( ds.Count > 0 )
        {
            Console.Write( "\nDataSet: [{0}", ds[ 0 ] );
            for( int iX = 1; iX < ds.Count; iX++ )
                Console.Write( ", {0}", ds[ iX ] );
            Console.WriteLine( "]\n" );
        }

        Console.WriteLine( fmt, "Convert.", "Default", 
            "Geometric Mean", "Median");
        Console.WriteLine( fmt, "--------", "-------", 
            "--------------", "------");
        Console.WriteLine( fmt, "ToBoolean", 
            Convert.ToBoolean( ds, null ), 
            Convert.ToBoolean( ds, geMean ), 
            Convert.ToBoolean( ds, median ) );
        Console.WriteLine( fmt, "ToByte", 
            Convert.ToByte( ds, null ), 
            Convert.ToByte( ds, geMean ), 
            Convert.ToByte( ds, median ) );
        Console.WriteLine( fmt, "ToChar", 
            Convert.ToChar( ds, null ), 
            Convert.ToChar( ds, geMean ), 
            Convert.ToChar( ds, median ) );
        Console.WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}" +
            "{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}", 
            "ToDateTime", Convert.ToDateTime( ds, null ), 
            Convert.ToDateTime( ds, geMean ), 
            Convert.ToDateTime( ds, median ) );
        Console.WriteLine( fmt, "ToDecimal", 
            Convert.ToDecimal( ds, null ), 
            Convert.ToDecimal( ds, geMean ), 
            Convert.ToDecimal( ds, median ) );
        Console.WriteLine( fmt, "ToDouble", 
            Convert.ToDouble( ds, null ), 
            Convert.ToDouble( ds, geMean ), 
            Convert.ToDouble( ds, median ) );
        Console.WriteLine( fmt, "ToInt16", 
            Convert.ToInt16( ds, null ), 
            Convert.ToInt16( ds, geMean ), 
            Convert.ToInt16( ds, median ) );
        Console.WriteLine( fmt, "ToInt32", 
            Convert.ToInt32( ds, null ), 
            Convert.ToInt32( ds, geMean ), 
            Convert.ToInt32( ds, median ) );
        Console.WriteLine( fmt, "ToInt64", 
            Convert.ToInt64( ds, null ), 
            Convert.ToInt64( ds, geMean ), 
            Convert.ToInt64( ds, median ) );
        Console.WriteLine( fmt, "ToSByte", 
            Convert.ToSByte( ds, null ), 
            Convert.ToSByte( ds, geMean ), 
            Convert.ToSByte( ds, median ) );
        Console.WriteLine( fmt, "ToSingle", 
            Convert.ToSingle( ds, null ), 
            Convert.ToSingle( ds, geMean ), 
            Convert.ToSingle( ds, median ) );
        Console.WriteLine( fmt, "ToUInt16", 
            Convert.ToUInt16( ds, null ), 
            Convert.ToUInt16( ds, geMean ), 
            Convert.ToUInt16( ds, median ) );
        Console.WriteLine( fmt, "ToUInt32", 
            Convert.ToUInt32( ds, null ), 
            Convert.ToUInt32( ds, geMean ), 
            Convert.ToUInt32( ds, median ) );
        Console.WriteLine( fmt, "ToUInt64", 
            Convert.ToUInt64( ds, null ), 
            Convert.ToUInt64( ds, geMean ), 
            Convert.ToUInt64( ds, median ) );
    }
   
    public static void Main( )
    {
        Console.WriteLine( "This example of " +
            "the Convert.To<Type>( object, IFormatProvider ) methods " +
            "\ngenerates the following output. The example " +
            "displays the values \nreturned by the methods, " +
            "using several IFormatProvider objects.\n" );
          
        DataSet ds1 = new DataSet( 
            10.5, 22.2, 45.9, 88.7, 156.05, 297.6 );
        DisplayDataSet( ds1 );
          
        DataSet ds2 = new DataSet( 
            359999.95, 425000, 499999.5, 775000, 1695000 );
        DisplayDataSet( ds2 );
    }
}

/*
This example of the Convert.To<Type>( object, IFormatProvider ) methods
generates the following output. The example displays the values
returned by the methods, using several IFormatProvider objects.

DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]

Convert.                 Default      Geometric Mean              Median
--------                 -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       103                  59                  67
ToChar                         g                   ;                   C
ToDateTime   2003-05-13 15:04:12 2003-05-13 15:03:28 2003-05-13 15:03:35
ToDecimal       103.491666666667    59.4332135445164                67.3
ToDouble        103.491666666667    59.4332135445164                67.3
ToInt16                      103                  59                  67
ToInt32                      103                  59                  67
ToInt64                      103                  59                  67
ToSByte                      103                  59                  67
ToSingle                103.4917            59.43321                67.3
ToUInt16                     103                  59                  67
ToUInt32                     103                  59                  67
ToUInt64                     103                  59                  67

DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]

Convert.                 Default      Geometric Mean              Median
--------                 -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       255                 255                 255
ToChar                         ?                   ?                   ?
ToDateTime   2003-05-22 07:39:08 2003-05-20 22:28:45 2003-05-19 09:55:48
ToDecimal              750999.89    631577.237188435            499999.5
ToDouble               750999.89    631577.237188435            499999.5
ToInt16                    32767               32767               32767
ToInt32                   751000              631577              500000
ToInt64                   751000              631577              500000
ToSByte                      127                 127                 127
ToSingle                750999.9            631577.3            499999.5
ToUInt16                   65535               65535               65535
ToUInt32                  751000              631577              500000
ToUInt64                  751000              631577              500000
*/
Imports System.Collections

Module IConvertibleProviderDemo

    ' Define the types of averaging available in the class 
    ' implementing IConvertible.
    Enum AverageType as Short
        None = 0
        GeometricMean = 1
        ArithmeticMean = 2
        Median = 3
    End Enum

    ' Pass an instance of this class to methods that require an 
    ' IFormatProvider. The class instance determines the type of 
    ' average to calculate.
    Public Class AverageInfo
        Implements IFormatProvider

        Protected  AvgType      As AverageType

        ' Specify the type of averaging in the constructor.
        Public Sub New( avgType As AverageType )
            Me.AvgType = avgType
        End Sub

        ' This method returns a reference to the containing object 
        ' if an object of AverageInfo type is requested. 
        Public Function GetFormat( argType As Type ) As Object _
            Implements IFormatProvider.GetFormat

            If argType Is GetType( AverageInfo ) Then
                Return Me
            Else
                Return Nothing
            End If
        End Function 

        ' Use this property to set or get the type of averaging.
        Public Property TypeOfAverage( ) As AverageType
            Get
                Return Me.AvgType
            End Get
            Set( ByVal value as AverageType )
                Me.AvgType = value
            End Set
        End Property
    End Class 

    ' This class encapsulates an array of Double values and implements 
    ' the IConvertible interface. Most of the IConvertible methods 
    ' return an average of the array elements in one of three types: 
    ' arithmetic mean, geometric mean, or median. 
    Public Class DataSet
        Implements IConvertible

        Protected data              As ArrayList
        Protected defaultProvider   As AverageInfo
           
        ' Construct the object and add an initial list of values.
        ' Create a default format provider.
        Public Sub New( ParamArray values( ) As Double )
            data = New ArrayList( values )
            defaultProvider = New AverageInfo( _
                AverageType.ArithmeticMean )  
        End Sub
           
        ' Add additional values with this method.
        Public Function Add( value As Double ) As Integer
            data.Add( value )
            Return data.Count
        End Function
           
        ' Get, set, and add values with this indexer property.
        Default Public Property Item(index As Integer) As Double
            Get
                If index >= 0 AndAlso index < data.Count Then
                    Return System.Convert.ToDouble( data( index ) )
                Else
                    Throw New InvalidOperationException( _
                        "[DataSet.get] Index out of range." )
                End If
            End Get
            Set
                If index >= 0 AndAlso index < data.Count Then
                    data( index ) = value
                 
                ElseIf index = data.Count Then
                    data.Add( value )
                Else
                    Throw New InvalidOperationException( _
                        "[DataSet.set] Index out of range." )
                End If
            End Set
        End Property
          
        ' This property returns the number of elements in the object.
        Public ReadOnly Property Count( ) As Integer
            Get
                Return data.Count
            End Get
        End Property

        ' This method calculates the average of the object's elements.
        Protected Function Average( ByVal avgType As AverageType ) As Double

            Dim SumProd As Double 
            Dim Index   As Integer

            If data.Count = 0 Then Return 0.0

            Select Case avgType
                
                Case AverageType.GeometricMean

                    SumProd = 1.0
                    For Index = 0 To data.Count - 1
                        SumProd *= data( Index )
                    Next Index
                    
                    ' This calculation will not fail with negative 
                    ' elements.
                    Return Math.Sign( SumProd ) * Math.Pow( _
                        Math.Abs( SumProd ), 1.0 / data.Count )

                Case AverageType.ArithmeticMean

                    SumProd = 0.0
                    For Index = 0 To data.Count - 1
                        SumProd += data( Index )
                    Next Index

                    Return SumProd / data.Count 

                Case AverageType.Median

                    If data.Count Mod 2 = 0 Then
                        Return ( data( data.Count \ 2 ) + _
                            data( data.Count \ 2 - 1 ) ) / 2.0
                    Else
                        Return data( data.Count \ 2 ) 
                    End If
            End Select
        End Function

        ' Get the AverageInfo object from the caller's format 
        ' provider, or use the local default.
        Protected Function GetAverageInfo( _
            provider As IFormatProvider ) As AverageInfo

            Dim avgInfo As AverageInfo = Nothing

            If Not provider Is Nothing Then
                avgInfo = provider.GetFormat( GetType( AverageInfo ) )
            End If

            Return IIf( avgInfo Is Nothing, defaultProvider, avgInfo )
            
        End Function           

        ' Calculate the average and limit the range.
        Protected Function CalcNLimitAverage( min As Double, _
            max As Double, provider as IFormatProvider ) As Double

            ' Get the format provider and calculate the average.
            Dim avgInfo As AverageInfo = GetAverageInfo( provider )
            Dim avg As Double = Average( avgInfo.TypeOfAverage )

            ' Limit the range, based on the minimum and maximum values 
            ' for the type.
            Return IIf( avg > max, max, IIf( avg < min, min, avg ) )

        End Function

        ' The following elements are required by IConvertible.

        ' None of these conversion functions throw exceptions. When
        ' the data is out of range for the type, the appropriate
        ' MinValue or MaxValue is used.
        Public Function GetTypeCode( ) As TypeCode _
            Implements IConvertible.GetTypeCode
            Return TypeCode.Object
        End Function

        Function ToBoolean( ByVal provider As IFormatProvider ) As _
            Boolean Implements IConvertible.ToBoolean

            ' ToBoolean is false if the dataset is empty.
            If data.Count <= 0 Then
                Return False

            ' For median averaging, ToBoolean is true if any 
            ' non-discarded elements are nonzero.
            ElseIf AverageType.Median = _
                GetAverageInfo( provider ).TypeOfAverage Then

                If data.Count Mod 2 = 0 Then
                    Return ( data( data.Count \ 2 ) <> 0.0 Or _
                        data( data.Count \ 2 - 1 ) <> 0.0 )
                Else
                    Return data( data.Count \ 2 ) <> 0.0
                End If

            ' For arithmetic or geometric mean averaging, ToBoolean is 
            ' true if any element of the dataset is nonzero.  
            Else
                Dim Index As Integer
                For Index = 0 To data.Count - 1
                    If data( Index ) <> 0.0 Then Return True
                Next Index
                Return False
            End If
        End Function

        Function ToByte( ByVal provider As IFormatProvider ) As Byte _
            Implements IConvertible.ToByte
            Return Convert.ToByte( CalcNLimitAverage( _
                Byte.MinValue, Byte.MaxValue, provider ) )
        End Function

        Function ToChar( ByVal provider As IFormatProvider ) As Char _
            Implements IConvertible.ToChar
            Return Convert.ToChar( Convert.ToUInt16( _
                CalcNLimitAverage( 0.0, &HFFFF, provider ) ) )
        End Function

        ' Convert to DateTime by adding the calculated average as 
        ' seconds to the current date and time. A valid DateTime is 
        ' always returned.
        Function ToDateTime( ByVal provider As IFormatProvider ) As _
            DateTime Implements IConvertible.ToDateTime
            Dim seconds As Double = Average( _
                GetAverageInfo( provider ).TypeOfAverage )
            Try
                Return DateTime.Now.AddSeconds( seconds )
            Catch ex As ArgumentOutOfRangeException 
                Return IIf( seconds < 0.0, DateTime.MinValue, _
                    DateTime.MaxValue )
            End Try
        End Function

        Function ToDecimal( ByVal provider As IFormatProvider ) As _
            Decimal Implements IConvertible.ToDecimal

            ' The Double conversion rounds Decimal.MinValue and
            ' Decimal.MaxValue to invalid Decimal values, so the 
            ' following limits must be used.
            Return Convert.ToDecimal( CalcNLimitAverage( _
                -79228162514264330000000000000.0, _
                79228162514264330000000000000.0, provider ) )
        End Function

        Function ToDouble( ByVal provider As IFormatProvider) As _
            Double Implements IConvertible.ToDouble
            Return Average( GetAverageInfo( provider ).TypeOfAverage )
        End Function

        Function ToInt16( ByVal provider As IFormatProvider ) As _
            Short Implements IConvertible.ToInt16
            Return Convert.ToInt16( CalcNLimitAverage( _
                Int16.MinValue, Int16.MaxValue, provider ) )
        End Function

        Function ToInt32( ByVal provider As IFormatProvider ) As _
            Integer Implements IConvertible.ToInt32
            Return Convert.ToInt32( CalcNLimitAverage( _
                Int32.MinValue, Int32.MaxValue, provider ) )
        End Function

        Function ToInt64( ByVal provider As IFormatProvider ) As Long _
            Implements IConvertible.ToInt64

            ' The Double conversion rounds Int64.MinValue and 
            ' Int64.MaxValue to invalid Long values, so the following 
            ' limits must be used.
            Return Convert.ToInt64( CalcNLimitAverage( _
                -9223372036854775000, 9223372036854775000, provider ) )
        End Function

        Function ToSByte( ByVal provider As IFormatProvider ) As _
            SByte Implements IConvertible.ToSByte

            ' SByte.MinValue and SByte.MaxValue are not defined in
            ' Visual Basic.
            Return Convert.ToSByte( CalcNLimitAverage( _
                -128, 127, provider ) )
        End Function

        Function ToSingle( ByVal provider As IFormatProvider ) As _
            Single Implements IConvertible.ToSingle
            Return Convert.ToSingle( CalcNLimitAverage( _
                Single.MinValue, Single.MaxValue, provider ) )
        End Function

        Function ToUInt16( ByVal provider As IFormatProvider ) As _
            UInt16 Implements IConvertible.ToUInt16

            ' UInt16.MinValue and UInt16.MaxValue are not defined in 
            ' Visual Basic.
            Return Convert.ToUInt16( CalcNLimitAverage( _
                0, &HFFFF, provider ) )
        End Function

        Function ToUInt32( ByVal provider As IFormatProvider ) As _
            UInt32 Implements IConvertible.ToUInt32

            ' UInt32.MinValue and UInt32.MaxValue are not defined in 
            ' Visual Basic.
            Return Convert.ToUInt32( CalcNLimitAverage( _
                0, 4294967295, provider ) )
        End Function

        Function ToUInt64( ByVal provider As IFormatProvider ) As _
            UInt64 Implements IConvertible.ToUInt64

            ' UInt64.MinValue and UInt64.MaxValue are not defined in 
            ' Visual Basic. The Double conversion would have rounded 
            ' UInt64.MaxValue, so the following limit must be used.
            Return Convert.ToUInt64( CalcNLimitAverage( _
                0, 18446744073709550000.0, provider ) )
        End Function

        Function ToType( ByVal conversionType As Type, _
            ByVal provider As IFormatProvider) As Object _
            Implements IConvertible.ToType
            Return Convert.ChangeType( Average( GetAverageInfo( _
                provider ).TypeOfAverage ), conversionType )
        End Function

        Overloads Function ToString( ByVal provider As IFormatProvider _
            ) As String Implements IConvertible.ToString
            Dim avgType as AverageType = _
                GetAverageInfo( provider ).TypeOfAverage
            Return String.Format( "( {0}: {1:G10} )", avgType, _
                Average( avgType ) )
        End Function
    End Class
   
    ' Display a DataSet with three different format providers.
    Sub DisplayDataSet( ds As DataSet )

        Dim fmt    As String      = "{0,-12}{1,20}{2,20}{3,20}"
        Dim median As AverageInfo = New AverageInfo( AverageType.Median )
        Dim geMean As AverageInfo = _
            New AverageInfo( AverageType.GeometricMean )
        Dim iX     As Integer

        ' Display the dataset elements.
        If ds.Count > 0 Then
            Console.Write( vbCrLf & "DataSet: [{0}", ds( 0 ) )
            For iX = 1 To ds.Count - 1
                Console.Write( ", {0}", ds( iX ) )
            Next iX
            Console.WriteLine( "]" & vbCrLf )
        End If

        Console.WriteLine( fmt, "Convert.", "Default", _
            "Geometric Mean", "Median" )
        Console.WriteLine( fmt, "--------", "-------", _
            "--------------", "------" )
        Console.WriteLine( fmt, "ToBoolean", _
            Convert.ToBoolean( ds, Nothing ), _
            Convert.ToBoolean( ds, geMean ), _
            Convert.ToBoolean( ds, median ) )
        Console.WriteLine( fmt, "ToByte", _
            Convert.ToByte( ds, Nothing ), _
            Convert.ToByte( ds, geMean ), _
            Convert.ToByte( ds, median ) )
        Console.WriteLine( fmt, "ToChar", _
            Convert.ToChar( ds, Nothing ), _
            Convert.ToChar( ds, geMean ), _
            Convert.ToChar( ds, median ) )
        Console.WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}" & _
            "{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}", _
            "ToDateTime", Convert.ToDateTime( ds, Nothing ), _
            Convert.ToDateTime( ds, geMean ), _
            Convert.ToDateTime( ds, median ) )
        Console.WriteLine( fmt, "ToDecimal", _
            Convert.ToDecimal( ds, Nothing ), _
            Convert.ToDecimal( ds, geMean ), _
            Convert.ToDecimal( ds, median ) )
        Console.WriteLine( fmt, "ToDouble", _
            Convert.ToDouble( ds, Nothing ), _
            Convert.ToDouble( ds, geMean ), _
            Convert.ToDouble( ds, median ) )
        Console.WriteLine( fmt, "ToInt16", _
            Convert.ToInt16( ds, Nothing ), _
            Convert.ToInt16( ds, geMean ), _
            Convert.ToInt16( ds, median ) )
        Console.WriteLine( fmt, "ToInt32", _
            Convert.ToInt32( ds, Nothing ), _
            Convert.ToInt32( ds, geMean ), _
            Convert.ToInt32( ds, median ) )
        Console.WriteLine( fmt, "ToInt64", _
            Convert.ToInt64( ds, Nothing ), _
            Convert.ToInt64( ds, geMean ), _
            Convert.ToInt64( ds, median ) )
        Console.WriteLine( fmt, "ToSByte", _
            Convert.ToSByte( ds, Nothing ), _
            Convert.ToSByte( ds, geMean ), _
            Convert.ToSByte( ds, median ) )
        Console.WriteLine( fmt, "ToSingle", _
            Convert.ToSingle( ds, Nothing ), _
            Convert.ToSingle( ds, geMean ), _
            Convert.ToSingle( ds, median ) )
        Console.WriteLine( fmt, "ToUInt16", _
            Convert.ToUInt16( ds, Nothing ), _
            Convert.ToUInt16( ds, geMean ), _
            Convert.ToUInt16( ds, median ) )
        Console.WriteLine( fmt, "ToUInt32", _
            Convert.ToUInt32( ds, Nothing ), _
            Convert.ToUInt32( ds, geMean ), _
            Convert.ToUInt32( ds, median ) )
        Console.WriteLine( fmt, "ToUInt64", _
            Convert.ToUInt64( ds, Nothing ), _
            Convert.ToUInt64( ds, geMean ), _
            Convert.ToUInt64( ds, median ) )
    End Sub
   
    Sub Main( )
        Console.WriteLine( _
            "This example of the Convert.To<Type>( Object, " & _
            "IFormatProvider ) methods " & vbCrLf & "generates " & _
            "the following output. The example displays the " & _
            "values " & vbCrLf & "returned by the methods, " & _
            "using several IFormatProvider objects." & vbCrLf )
          
        Dim ds1 As New DataSet( 10.5, 22.2, 45.9, 88.7, 156.05, 297.6 )
        DisplayDataSet( ds1 )
          
        Dim ds2 As New DataSet( _
            359999.95, 425000, 499999.5, 775000, 1695000 )
        DisplayDataSet( ds2 )
    End Sub 
End Module 

' This example of the Convert.To<Type>( Object, IFormatProvider ) methods
' generates the following output. The example displays the values
' returned by the methods, using several IFormatProvider objects.
' 
' DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]
' 
' Convert.                 Default      Geometric Mean              Median
' --------                 -------      --------------              ------
' ToBoolean                   True                True                True
' ToByte                       103                  59                  67
' ToChar                         g                   ;                   C
' ToDateTime   2003-05-13 14:52:53 2003-05-13 14:52:09 2003-05-13 14:52:17
' ToDecimal       103.491666666667    59.4332135445164                67.3
' ToDouble        103.491666666667    59.4332135445164                67.3
' ToInt16                      103                  59                  67
' ToInt32                      103                  59                  67
' ToInt64                      103                  59                  67
' ToSByte                      103                  59                  67
' ToSingle                103.4917            59.43321                67.3
' ToUInt16                     103                  59                  67
' ToUInt32                     103                  59                  67
' ToUInt64                     103                  59                  67
' 
' DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]
' 
' Convert.                 Default      Geometric Mean              Median
' --------                 -------      --------------              ------
' ToBoolean                   True                True                True
' ToByte                       255                 255                 255
' ToChar                         ?                   ?                   ?
' ToDateTime   2003-05-22 07:27:49 2003-05-20 22:17:27 2003-05-19 09:44:29
' ToDecimal              750999.89    631577.237188435            499999.5
' ToDouble               750999.89    631577.237188435            499999.5
' ToInt16                    32767               32767               32767
' ToInt32                   751000              631577              500000
' ToInt64                   751000              631577              500000
' ToSByte                      127                 127                 127
' ToSingle                750999.9            631577.3            499999.5
' ToUInt16                   65535               65535               65535
' ToUInt32                  751000              631577              500000
' ToUInt64                  751000              631577              500000

Remarks

The return value is the result of invoking the IConvertible.ToInt64 method of the underlying type of value.

provider enables the user to specify culture-specific conversion information about the contents of value. For example, if value is a String that represents a number, provider could supply culture-specific information about the notation used to represent that number.

The base types ignore provider; however, the parameter may be used if value is a user-defined type that implements the IConvertible interface.

ToInt64(UInt64)

Important

This API is not CLS-compliant.

Converts the value of the specified 64-bit unsigned integer to an equivalent 64-bit signed integer.

[System.CLSCompliant(false)]
public static long ToInt64 (ulong value);
Parameters
value
UInt64

The 64-bit unsigned integer to convert.

Returns

A 64-bit signed integer that is equivalent to value.

Exceptions

value is greater than MaxValue.

Examples

The following example attempts to convert each element in an array of unsigned long integers to a long integer.

ulong[] numbers = { UInt64.MinValue, 121, 340, UInt64.MaxValue };
long result;
foreach (ulong number in numbers)
{
   try {
      result = Convert.ToInt64(number);
      Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int64 type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt64 value 0 to a Int32 value 0.
//    Converted the UInt64 value 121 to a Int32 value 121.
//    Converted the UInt64 value 340 to a Int32 value 340.
//    The UInt64 value 18446744073709551615 is outside the range of the Int64 type.
Dim numbers() As ULong = { UInt64.MinValue, 121, 340, UInt64.MaxValue }
Dim result As Long

For Each number As ULong In numbers
   Try
      result = Convert.ToInt64(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int64 type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt64 value 0 to the Int64 value 0.
'    Converted the UInt64 value 121 to the Int64 value 121.
'    Converted the UInt64 value 340 to the Int64 value 340.
'    The UInt64 value 18446744073709551615 is outside the range of the Int64 type.

ToInt64(UInt32)

Important

This API is not CLS-compliant.

Converts the value of the specified 32-bit unsigned integer to an equivalent 64-bit signed integer.

[System.CLSCompliant(false)]
public static long ToInt64 (uint value);
Parameters
value
UInt32

The 32-bit unsigned integer to convert.

Returns

A 64-bit signed integer that is equivalent to value.

Examples

The following example converts each element in an array of unsigned integers to a long integer.

uint[] numbers = { UInt32.MinValue, 121, 340, UInt32.MaxValue };
long result;
foreach (uint number in numbers)
{
   result = Convert.ToInt64(number);
   Console.WriteLine("Converted the {0} value {1:N0} to the {2} value {3:N0}.",
                     number.GetType().Name, number,
                     result.GetType().Name, result);
}
// The example displays the following output:
//    Converted the UInt32 value 0 to the Int64 value 0.
//    Converted the UInt32 value 121 to the Int64 value 121.
//    Converted the UInt32 value 340 to the Int64 value 340.
//    Converted the UInt32 value 4,294,967,295 to the Int64 value 4,294,967,295.
Dim numbers() As UInteger = { UInt32.MinValue, 121, 340, UInt32.MaxValue }
Dim result As Long
For Each number As UInteger In numbers
   result = Convert.ToInt64(number)
   Console.WriteLine("Converted the {0} value {1:N0} to the {2} value {3:N0}.", _
                     number.GetType().Name, number, _
                     result.GetType().Name, result)
Next
' The example displays the following output:
'    Converted the UInt32 value 0 to the Int64 value 0.
'    Converted the UInt32 value 121 to the Int64 value 121.
'    Converted the UInt32 value 340 to the Int64 value 340.
'    Converted the UInt32 value 4,294,967,295 to the Int64 value 4,294,967,295.

ToInt64(UInt16)

Important

This API is not CLS-compliant.

Converts the value of the specified 16-bit unsigned integer to the equivalent 64-bit signed integer.

[System.CLSCompliant(false)]
public static long ToInt64 (ushort value);
Parameters
value
UInt16

The 16-bit unsigned integer to convert.

Returns

A 64-bit signed integer that is equivalent to value.

Examples

The following example converts each element in an array of 16-bit unsigned integers to a long integer.

ushort[] numbers = { UInt16.MinValue, 121, 340, UInt16.MaxValue };
long result;
foreach (ushort number in numbers)
{
   try {
      result = Convert.ToInt64(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int64 type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt16 value 0 to the Int64 value 0.
//    Converted the UInt16 value 121 to the Int64 value 121.
//    Converted the UInt16 value 340 to the Int64 value 340.
//    Converted the UInt16 value 65535 to the Int64 value 65535.
Dim numbers() As UShort = { UInt16.MinValue, 121, 340, UInt16.MaxValue }
Dim result As Long
For Each number As UShort In numbers
   Try
      result = Convert.ToInt64(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int64 type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt16 value 0 to the Int64 value 0.
'    Converted the UInt16 value 121 to the Int64 value 121.
'    Converted the UInt16 value 340 to the Int64 value 340.
'    Converted the UInt16 value 65535 to the Int64 value 65535.

ToInt64(String)

Converts the specified string representation of a number to an equivalent 64-bit signed integer.

public static long ToInt64 (string value);
Parameters
value
String

A string that contains a number to convert.

Returns

A 64-bit signed integer that is equivalent to the number in value, or 0 (zero) if value is null.

Exceptions

value does not consist of an optional sign followed by a sequence of digits (0 through 9).

value represents a number that is less than MinValue or greater than MaxValue.

Examples

The following example attempts to convert each element in an array of numeric strings to a long integer.

string[] values = { "One", "1.34e28", "-26.87", "-18", "-6.00",
                    " 0", "137", "1601.9", Int32.MaxValue.ToString() };
long result;

foreach (string value in values)
{
   try {
      result = Convert.ToInt64(value);
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
                        value.GetType().Name, value, result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("{0} is outside the range of the Int64 type.", value);
   }   
   catch (FormatException) {
      Console.WriteLine("The {0} value '{1}' is not in a recognizable format.",
                        value.GetType().Name, value);
   }   
}                                 
// The example displays the following output:
//    The String value 'One' is not in a recognizable format.
//    The String value '1.34e28' is not in a recognizable format.
//    The String value '-26.87' is not in a recognizable format.
//    Converted the String value '-18' to the Int64 value -18.
//    The String value '-6.00' is not in a recognizable format.
//    Converted the String value ' 0' to the Int64 value 0.
//    Converted the String value '137' to the Int64 value 137.
//    The String value '1601.9' is not in a recognizable format.
//    Converted the String value '2147483647' to the Int64 value 2147483647.
Dim values() As String = { "One", "1.34e28", "-26.87", "-18", "-6.00", _
                           " 0", "137", "1601.9", Int32.MaxValue.ToString() }
Dim result As Long

For Each value As String In values
   Try
      result = Convert.ToInt64(value)
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
                        value.GetType().Name, value, result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("{0} is outside the range of the Int64 type.", value)
   Catch e As FormatException
      Console.WriteLine("The {0} value '{1}' is not in a recognizable format.", _
                        value.GetType().Name, value)
   End Try   
Next                                 
' The example displays the following output:
'    The String value 'One' is not in a recognizable format.
'    The String value '1.34e28' is not in a recognizable format.
'    The String value '-26.87' is not in a recognizable format.
'    Converted the String value '-18' to the Int64 value -18.
'    The String value '-6.00' is not in a recognizable format.
'    Converted the String value ' 0' to the Int64 value 0.
'    Converted the String value '137' to the Int64 value 137.
'    The String value '1601.9' is not in a recognizable format.
'    Converted the String value '2147483647' to the Int64 value 2147483647.

Remarks

Using the ToInt64(String) method is equivalent to passing value to the Int64.Parse(String) method. value is interpreted by using the formatting conventions of the current thread culture.

If you prefer not to handle an exception if the conversion fails, you can call the Int64.TryParse method instead. It returns a Boolean value that indicates whether the conversion succeeded or failed.

ToInt64(SByte)

Important

This API is not CLS-compliant.

Converts the value of the specified 8-bit signed integer to the equivalent 64-bit signed integer.

[System.CLSCompliant(false)]
public static long ToInt64 (sbyte value);
Parameters
value
SByte

The 8-bit signed integer to convert.

Returns

A 64-bit signed integer that is equivalent to value.

Examples

The following example converts each element in a signed byte array to a long integer.

sbyte[] numbers = { SByte.MinValue, -1, 0, 10, SByte.MaxValue };
long result;

foreach (sbyte number in numbers)
{
   result = Convert.ToInt64(number);
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                     number.GetType().Name, number,
                     result.GetType().Name, result);
}
// The example displays the following output:
//       Converted the SByte value -128 to the Int64 value -128.
//       Converted the SByte value -1 to the Int64 value -1.
//       Converted the SByte value 0 to the Int64 value 0.
//       Converted the SByte value 10 to the Int64 value 10.
//       Converted the SByte value 127 to the Int64 value 127.
Dim numbers() As SByte = { SByte.MinValue, -1, 0, 10, SByte.MaxValue }
Dim result As Long

For Each number As SByte In numbers
   result = Convert.ToInt64(number)
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                     number.GetType().Name, number, _
                     result.GetType().Name, result)
Next
' The example displays the following output:
'       Converted the SByte value -128 to the Int64 value -128.
'       Converted the SByte value -1 to the Int64 value -1.
'       Converted the SByte value 0 to the Int64 value 0.
'       Converted the SByte value 10 to the Int64 value 10.
'       Converted the SByte value 127 to the Int64 value 127.

ToInt64(Object)

Converts the value of the specified object to a 64-bit signed integer.

public static long ToInt64 (object value);
Parameters
value
Object

An object that implements the IConvertible interface, or null.

Returns

A 64-bit signed integer that is equivalent to value, or zero if value is null.

Exceptions

value is not in an appropriate format.

value does not implement the IConvertible interface.

-or-

The conversion is not supported.

value represents a number that is less than MinValue or greater than MaxValue.

Examples

The following example attempts to convert each element in an object array to a long integer.

object[] values = { true, -12, 163, 935, 'x', new DateTime(2009, 5, 12),
                    "104", "103.0", "-1",
                    "1.00e2", "One", 1.00e2, 16.3e42};
long result;

foreach (object value in values)
{
   try {
      result = Convert.ToInt64(value);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        value.GetType().Name, value,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int64 type.",
                        value.GetType().Name, value);
   }                     
   catch (FormatException) {
      Console.WriteLine("The {0} value {1} is not in a recognizable format.",
                        value.GetType().Name, value);
   }
   catch (InvalidCastException) {
      Console.WriteLine("No conversion to an Int64 exists for the {0} value {1}.",
                        value.GetType().Name, value);
                        
   }
}                           
// The example displays the following output:
//    Converted the Boolean value True to the Int64 value 1.
//    Converted the Int32 value -12 to the Int64 value -12.
//    Converted the Int32 value 163 to the Int64 value 163.
//    Converted the Int32 value 935 to the Int64 value 935.
//    Converted the Char value x to the Int64 value 120.
//    No conversion to an Int64 exists for the DateTime value 5/12/2009 12:00:00 AM.
//    Converted the String value 104 to the Int64 value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the Int64 value -1.
//    The String value 1.00e2 is not in a recognizable format.
//    The String value One is not in a recognizable format.
//    Converted the Double value 100 to the Int64 value 100.
//    The Double value 1.63E+43 is outside the range of the Int64 type.
Dim values() As Object = { True, -12, 163, 935, "x"c, #5/12/2009#, _
                           "104", "103.0", "-1", _
                           "1.00e2", "One", 1.00e2, 16.3e42}
Dim result As Long

For Each value As Object In values
   Try
      result = Convert.ToInt64(value)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        value.GetType().Name, value, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int64 type.", _
                        value.GetType().Name, value)
   Catch e As FormatException
      Console.WriteLine("The {0} value {1} is not in a recognizable format.", _
                        value.GetType().Name, value)
   Catch e As InvalidCastException
      Console.WriteLine("No conversion to an Int64 exists for the {0} value {1}.", _
                        value.GetType().Name, value)
                        
   End Try
Next                           
' The example displays the following output:
'    Converted the Boolean value True to the Int64 value 1.
'    Converted the Int64 value -12 to the Int64 value -12.
'    Converted the Int64 value 163 to the Int64 value 163.
'    Converted the Int64 value 935 to the Int64 value 935.
'    Converted the Char value x to the Int64 value 120.
'    No conversion to an Int64 exists for the DateTime value 5/12/2009 12:00:00 AM.
'    Converted the String value 104 to the Int64 value 104.
'    The String value 103.0 is not in a recognizable format.
'    Converted the String value -1 to the Int64 value -1.
'    The String value 1.00e2 is not in a recognizable format.
'    The String value One is not in a recognizable format.
'    Converted the Double value 100 to the Int64 value 100.
'    The Double value 1.63E+43 is outside the range of the Int64 type.

Remarks

If value is not null, this method wraps a call to the IConvertible.ToInt64 implementation of the underlying type of value.

ToInt64(Int64)

Returns the specified 64-bit signed integer; no actual conversion is performed.

public static long ToInt64 (long value);
Parameters
value
Int64

A 64-bit signed integer.

Returns

value is returned unchanged.

Examples

The following example converts each element in an array of integers to a long integer.

int[] numbers = { Int32.MinValue, -1, 0, 121, 340, Int32.MaxValue };
long result;
foreach (int number in numbers)
{
   result = Convert.ToInt64(number);
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                     number.GetType().Name, number,
                     result.GetType().Name, result);
}
// The example displays the following output:
//    Converted the Int32 value -2147483648 to the Int64 value -2147483648.
//    Converted the Int32 value -1 to the Int64 value -1.
//    Converted the Int32 value 0 to the Int64 value 0.
//    Converted the Int32 value 121 to the Int64 value 121.
//    Converted the Int32 value 340 to the Int64 value 340.
//    Converted the Int32 value 2147483647 to the Int64 value 2147483647.
Dim numbers() As Integer = { Int32.MinValue, -1, 0, 121, 340, Int32.MaxValue }
Dim result As Long
For Each number As Integer In numbers
   result = Convert.ToInt64(number)
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                     number.GetType().Name, number, _
                     result.GetType().Name, result)
Next
' The example displays the following output:
'    Converted the Int32 value -2147483648 to the Int64 value -2147483648.
'    Converted the Int32 value -1 to the Int64 value -1.
'    Converted the Int32 value 0 to the Int64 value 0.
'    Converted the Int32 value 121 to the Int64 value 121.
'    Converted the Int32 value 340 to the Int64 value 340.
'    Converted the Int32 value 2147483647 to the Int64 value 2147483647.

ToInt64(Byte)

Converts the value of the specified 8-bit unsigned integer to the equivalent 64-bit signed integer.

public static long ToInt64 (byte value);
Parameters
value
Byte

The 8-bit unsigned integer to convert.

Returns

A 64-bit signed integer that is equivalent to value.

Examples

The following example converts each element in an array of bytes to a long integer.

byte[] bytes = { Byte.MinValue, 14, 122, Byte.MaxValue};
long result;

foreach (byte byteValue in bytes)
{
   result = Convert.ToInt64(byteValue);
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                     byteValue.GetType().Name, byteValue,
                     result.GetType().Name, result);
}
// The example displays the following output:
//       Converted the Byte value 0 to the Int64 value 0.
//       Converted the Byte value 14 to the Int64 value 14.
//       Converted the Byte value 122 to the Int64 value 122.
//       Converted the Byte value 255 to the Int64 value 255.
Dim bytes() As Byte = { Byte.MinValue, 14, 122, Byte.MaxValue}
Dim result As Long

For Each byteValue As Byte In bytes
   result = Convert.ToInt64(byteValue)
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                     byteValue.GetType().Name, byteValue, _
                     result.GetType().Name, result)
Next
' The example displays the following output:
'    Converted the Byte value 0 to the Int64 value 0.
'    Converted the Byte value 14 to the Int64 value 14.
'    Converted the Byte value 122 to the Int64 value 122.
'    Converted the Byte value 255 to the Int64 value 255.

ToInt64(Char)

Converts the value of the specified Unicode character to the equivalent 64-bit signed integer.

public static long ToInt64 (char value);
Parameters
value
Char

The Unicode character to convert.

Returns

A 64-bit signed integer that is equivalent to value.

Examples

The following example converts each element in a Char array to a long integer.

char[] chars = { 'a', 'z', '\u0007', '\u03FF',
                 '\u7FFF', '\uFFFE' };
long result;
                        
foreach (char ch in chars)
{
   result = Convert.ToInt64(ch);
   Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
                     ch.GetType().Name, ch,
                     result.GetType().Name, result);
}   
// The example displays the following output:
//       Converted the Char value 'a' to the Int64 value 97.
//       Converted the Char value 'z' to the Int64 value 122.
//       Converted the Char value '' to the Int64 value 7.
//       Converted the Char value '?' to the Int64 value 1023.
//       Converted the Char value '?' to the Int64 value 32767.
//       Converted the Char value '?' to the Int64 value 65534.
Dim chars() As Char = { "a"c, "z"c, ChrW(7), ChrW(1023), _
                        ChrW(Short.MaxValue), ChrW(&hFFFE) }
Dim result As Long
                        
For Each ch As Char in chars
   result = Convert.ToInt64(ch)
   Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
                     ch.GetType().Name, ch, _
                     result.GetType().Name, result)
Next   
' The example displays the following output:
'       Converted the Char value 'a' to the Int64 value 97.
'       Converted the Char value 'z' to the Int64 value 122.
'       Converted the Char value '' to the Int64 value 7.
'       Converted the Char value '?' to the Int64 value 1023.
'       Converted the Char value '?' to the Int64 value 32767.
'       Converted the Char value '?' to the Int64 value 65534.

ToInt64(DateTime)

Calling this method always throws InvalidCastException.

public static long ToInt64 (DateTime value);
Parameters
value
DateTime

The date and time value to convert.

Returns

This conversion is not supported. No value is returned.

Exceptions

This conversion is not supported.

ToInt64(Boolean)

Converts the specified Boolean value to the equivalent 64-bit signed integer.

public static long ToInt64 (bool value);
Parameters
value
Boolean

The Boolean value to convert.

Returns

The number 1 if value is true; otherwise, 0.

Examples

The following example converts the Boolean values true and false to long integers.

bool falseFlag = false;
bool trueFlag = true;

Console.WriteLine("{0} converts to {1}.", falseFlag,
                  Convert.ToInt64(falseFlag));
Console.WriteLine("{0} converts to {1}.", trueFlag,
                  Convert.ToInt64(trueFlag));
// The example displays the following output:
//       False converts to 0.
//       True converts to 1.
Dim falseFlag As Boolean = False
Dim trueFlag As Boolean = True

Console.WriteLine("{0} converts to {1}.", falseFlag, _
                  Convert.ToInt64(falseFlag))
Console.WriteLine("{0} converts to {1}.", trueFlag, _
                  Convert.ToInt64(trueFlag))
' The example displays the following output:
'       False converts to 0.
'       True converts to 1.

ToInt64(Double)

Converts the value of the specified double-precision floating-point number to an equivalent 64-bit signed integer.

public static long ToInt64 (double value);
Parameters
value
Double

The double-precision floating-point number to convert.

Returns

value, rounded to the nearest 64-bit signed integer. If value is halfway between two whole numbers, the even number is returned; that is, 4.5 is converted to 4, and 5.5 is converted to 6.

Exceptions

value is greater than MaxValue or less than MinValue.

Examples

The following example attempts to convert each element in an array of Double values to a long integer.

double[] values= { Double.MinValue, -1.38e10, -1023.299, -12.98,
                   0, 9.113e-16, 103.919, 17834.191, Double.MaxValue };
long result;

foreach (double value in values)
{
   try {
      result = Convert.ToInt64(value);
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
                        value.GetType().Name, value,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("{0} is outside the range of the Int64 type.", value);
   }   
}                                 
//    -1.79769313486232E+308 is outside the range of the Int64 type.
//    -13800000000 is outside the range of the Int16 type.
//    Converted the Double value '-1023.299' to the Int64 value -1023.
//    Converted the Double value '-12.98' to the Int64 value -13.
//    Converted the Double value '0' to the Int64 value 0.
//    Converted the Double value '9.113E-16' to the Int64 value 0.
//    Converted the Double value '103.919' to the Int64 value 104.
//    Converted the Double value '17834.191' to the Int64 value 17834.
//    1.79769313486232E+308 is outside the range of the Int64 type.
Dim values() As Double = { Double.MinValue, -1.38e10, -1023.299, -12.98, _
                           0, 9.113e-16, 103.919, 17834.191, Double.MaxValue }
Dim result As Long

For Each value As Double In values
   Try
      result = Convert.ToInt64(value)
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
                        value.GetType().Name, value, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("{0} is outside the range of the Int64 type.", value)
   End Try   
Next                                 
'    -1.79769313486232E+308 is outside the range of the Int64 type.
'    -13800000000 is outside the range of the Int16 type.
'    Converted the Double value '-1023.299' to the Int64 value -1023.
'    Converted the Double value '-12.98' to the Int64 value -13.
'    Converted the Double value '0' to the Int64 value 0.
'    Converted the Double value '9.113E-16' to the Int64 value 0.
'    Converted the Double value '103.919' to the Int64 value 104.
'    Converted the Double value '17834.191' to the Int64 value 17834.
'    1.79769313486232E+308 is outside the range of the Int64 type.
See Also

ToInt64(Int16)

Converts the value of the specified 16-bit signed integer to an equivalent 64-bit signed integer.

public static long ToInt64 (short value);
Parameters
value
Int16

The 16-bit signed integer to convert.

Returns

A 64-bit signed integer that is equivalent to value.

Examples

The following example converts each element in an array of 16-bit integers to a long integer.

short[] numbers= { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue };
long result;

foreach (short number in numbers)
{
   result = Convert.ToInt64(number);
   Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
}
// The example displays the following output:
//    Converted the Int16 value -32768 to a Int32 value -32768.
//    Converted the Int16 value -1 to a Int32 value -1.
//    Converted the Int16 value 0 to a Int32 value 0.
//    Converted the Int16 value 121 to a Int32 value 121.
//    Converted the Int16 value 340 to a Int32 value 340.
//    Converted the Int16 value 32767 to a Int32 value 32767.
Dim numbers() As Short = { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue }
Dim result As Long

For Each number As Short In numbers
   result = Convert.ToInt64(number)
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
Next
' The example displays the following output:
'    Converted the Int16 value -32768 to the Int64 value -32768.
'    Converted the Int16 value -1 to the Int64 value -1.
'    Converted the Int16 value 0 to the Int64 value 0.
'    Converted the Int16 value 121 to the Int64 value 121.
'    Converted the Int16 value 340 to the Int64 value 340.
'    Converted the Int16 value 32767 to the Int64 value 32767.

ToInt64(Int32)

Converts the value of the specified 32-bit signed integer to an equivalent 64-bit signed integer.

public static long ToInt64 (int value);
Parameters
value
Int32

The 32-bit signed integer to convert.

Returns

A 64-bit signed integer that is equivalent to value.

ToInt64(Decimal)

Converts the value of the specified decimal number to an equivalent 64-bit signed integer.

public static long ToInt64 (decimal value);
Parameters
value
Decimal

The decimal number to convert.

Returns

value, rounded to the nearest 64-bit signed integer. If value is halfway between two whole numbers, the even number is returned; that is, 4.5 is converted to 4, and 5.5 is converted to 6.

Exceptions

value is greater than MaxValue or less than MinValue.

Examples

The following example attempts to convert each element in an array of Decimal values to a long integer.

decimal[] values= { Decimal.MinValue, -1034.23m, -12m, 0m, 147m,
                    199.55m, 9214.16m, Decimal.MaxValue };
long result;

foreach (decimal value in values)
{
   try {
      result = Convert.ToInt64(value);
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
                        value.GetType().Name, value,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("{0} is outside the range of the Int64 type.",
                        value);
   }   
}                                  
// The example displays the following output:
//    -79228162514264337593543950335 is outside the range of the Int64 type.
//    Converted the Decimal value '-1034.23' to the Int64 value -1034.
//    Converted the Decimal value '-12' to the Int64 value -12.
//    Converted the Decimal value '0' to the Int64 value 0.
//    Converted the Decimal value '147' to the Int64 value 147.
//    Converted the Decimal value '199.55' to the Int64 value 200.
//    Converted the Decimal value '9214.16' to the Int64 value 9214.
//    79228162514264337593543950335 is outside the range of the Int64 type.
Dim values() As Decimal = { Decimal.MinValue, -1034.23d, -12d, 0d, 147d, _
                            199.55d, 9214.16d, Decimal.MaxValue }
Dim result As Long

For Each value As Decimal In values
   Try
      result = Convert.ToInt64(value)
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
                        value.GetType().Name, value, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("{0} is outside the range of the Int64 type.", _
                        value)
   End Try   
Next                                  
' The example displays the following output:
'    -79228162514264337593543950335 is outside the range of the Int64 type.
'    Converted the Decimal value '-1034.23' to the Int64 value -1034.
'    Converted the Decimal value '-12' to the Int64 value -12.
'    Converted the Decimal value '0' to the Int64 value 0.
'    Converted the Decimal value '147' to the Int64 value 147.
'    Converted the Decimal value '199.55' to the Int64 value 200.
'    Converted the Decimal value '9214.16' to the Int64 value 9214.
'    79228162514264337593543950335 is outside the range of the Int64 type.

Applies to