IConvertible IConvertible IConvertible IConvertible Interface

Definizione

Importante

Questa API non è conforme a CLS.

Definisce i metodi che convertono il valore del tipo di valore o di riferimento di implementazione in un tipo Common Language Runtime con un valore equivalente.Defines methods that convert the value of the implementing reference or value type to a common language runtime type that has an equivalent value.

public interface class IConvertible
[System.CLSCompliant(false)]
[System.Runtime.InteropServices.ComVisible(true)]
public interface IConvertible
type IConvertible = interface
Public Interface IConvertible
Derivato
Attributi

Esempi

Nell'esempio di codice seguente viene illustrata IConvertible un'implementazione di per una classe di numeri complessi, in modo da consentirne il cast prima Convert Double come e quindi Doublechiamare i membri statici.The following code sample demonstrates an implementation of IConvertible for a Complex number class, allowing it to be cast first as a Double and then calling the static Convert members on that Double.

#using <System.dll>

using namespace System;

/// Class that implements IConvertible
ref class Complex: public IConvertible
{
private:
   double x;
   double y;

public:
   Complex( double x, double y )
   {
      this->x = x;
      this->y = y;
   }

   virtual TypeCode GetTypeCode()
   {
      return TypeCode::Object;
   }

   virtual bool ToBoolean( IFormatProvider^ /*provider*/ ) = IConvertible::ToBoolean
   {
      if ( (x != 0.0) || (y != 0.0) )
            return true;
      else
            return false;
   }

   double GetDoubleValue()
   {
      return Math::Sqrt( x * x + y * y );
   }

   virtual Byte ToByte( IFormatProvider^ /*provider*/ ) = IConvertible::ToByte
   {
      return Convert::ToByte( GetDoubleValue() );
   }

   virtual Char ToChar( IFormatProvider^ /*provider*/ ) = IConvertible::ToChar
   {
      return Convert::ToChar( GetDoubleValue() );
   }

   virtual DateTime ToDateTime( IFormatProvider^ /*provider*/ ) = IConvertible::ToDateTime
   {
      return Convert::ToDateTime( GetDoubleValue() );
   }

   virtual Decimal ToDecimal( IFormatProvider^ /*provider*/ ) = IConvertible::ToDecimal
   {
      return Convert::ToDecimal( GetDoubleValue() );
   }

   virtual double ToDouble( IFormatProvider^ /*provider*/ ) = IConvertible::ToDouble
   {
      return GetDoubleValue();
   }

   virtual short ToInt16( IFormatProvider^ /*provider*/ ) = IConvertible::ToInt16
   {
      return Convert::ToInt16( GetDoubleValue() );
   }

   virtual int ToInt32( IFormatProvider^ /*provider*/ ) = IConvertible::ToInt32
   {
      return Convert::ToInt32( GetDoubleValue() );
   }

   virtual Int64 ToInt64( IFormatProvider^ /*provider*/ ) = IConvertible::ToInt64
   {
      return Convert::ToInt64( GetDoubleValue() );
   }

   virtual signed char ToSByte( IFormatProvider^ /*provider*/ ) = IConvertible::ToSByte
   {
      return Convert::ToSByte( GetDoubleValue() );
   }

   virtual float ToSingle( IFormatProvider^ /*provider*/ ) = IConvertible::ToSingle
   {
      return Convert::ToSingle( GetDoubleValue() );
   }

   virtual String^ ToString( IFormatProvider^ /*provider*/ ) = IConvertible::ToString
   {
      return String::Format( "( {0} , {1} )", x, y );
   }

   virtual Object^ ToType( Type^ conversionType, IFormatProvider^ /*provider*/ ) = IConvertible::ToType
   {
      return Convert::ChangeType( GetDoubleValue(), conversionType );
   }

   virtual UInt16 ToUInt16( IFormatProvider^ /*provider*/ ) = IConvertible::ToUInt16
   {
      return Convert::ToUInt16( GetDoubleValue() );
   }

   virtual UInt32 ToUInt32( IFormatProvider^ /*provider*/ ) = IConvertible::ToUInt32
   {
      return Convert::ToUInt32( GetDoubleValue() );
   }

   virtual UInt64 ToUInt64( IFormatProvider^ /*provider*/ ) = IConvertible::ToUInt64
   {
      return Convert::ToUInt64( GetDoubleValue() );
   }

};

void WriteObjectInfo( Object^ testObject )
{
   TypeCode typeCode = Type::GetTypeCode( testObject->GetType() );
   switch ( typeCode )
   {
      case TypeCode::Boolean:
         Console::WriteLine( "Boolean: {0}", testObject );
         break;

      case TypeCode::Double:
         Console::WriteLine( "Double: {0}", testObject );
         break;

      default:
         Console::WriteLine( "{0}: {1}", typeCode, testObject );
         break;
   }
}

int main()
{
   Complex^ testComplex = gcnew Complex( 4,7 );
   WriteObjectInfo( testComplex );
   WriteObjectInfo( Convert::ToBoolean( testComplex ) );
   WriteObjectInfo( Convert::ToDecimal( testComplex ) );
   WriteObjectInfo( Convert::ToString( testComplex ) );
}
using System;

namespace ConsoleApplication2
{

	/// Class that implements IConvertible
	class Complex : IConvertible
	{
		double	x;
		double	y;

		public Complex(double x, double y)
		{
			this.x = x;
			this.y = y;
		}

		public TypeCode GetTypeCode()
		{
			return TypeCode.Object;
		}

		bool IConvertible.ToBoolean(IFormatProvider provider)
		{
			if(	(x != 0.0) || (y != 0.0) )
				return true;
			else
				return false;
		}

		double GetDoubleValue()
		{
			return Math.Sqrt(x*x + y*y);
		}

		byte IConvertible.ToByte(IFormatProvider provider)
		{
			return Convert.ToByte(GetDoubleValue());
		}

		char IConvertible.ToChar(IFormatProvider provider)
		{
			return Convert.ToChar(GetDoubleValue());
		}

		DateTime IConvertible.ToDateTime(IFormatProvider provider)
		{
			return Convert.ToDateTime(GetDoubleValue());
		}

		decimal IConvertible.ToDecimal(IFormatProvider provider)
		{
			return Convert.ToDecimal(GetDoubleValue());
		}

		double IConvertible.ToDouble(IFormatProvider provider)
		{
			return GetDoubleValue();
		}

		short IConvertible.ToInt16(IFormatProvider provider)
		{
			return Convert.ToInt16(GetDoubleValue());
		}

		int IConvertible.ToInt32(IFormatProvider provider)
		{
			return Convert.ToInt32(GetDoubleValue());
		}

		long IConvertible.ToInt64(IFormatProvider provider)
		{
			return Convert.ToInt64(GetDoubleValue());
		}

		sbyte IConvertible.ToSByte(IFormatProvider provider)
		{
			return Convert.ToSByte(GetDoubleValue());
		}

		float IConvertible.ToSingle(IFormatProvider provider)
		{
			return Convert.ToSingle(GetDoubleValue());
		}

		string IConvertible.ToString(IFormatProvider provider)
		{
			return String.Format("({0}, {1})", x, y);
		}

		object IConvertible.ToType(Type conversionType, IFormatProvider provider)
		{
			return Convert.ChangeType(GetDoubleValue(),conversionType);
		}

		ushort IConvertible.ToUInt16(IFormatProvider provider)
		{
			return Convert.ToUInt16(GetDoubleValue());
		}

		uint IConvertible.ToUInt32(IFormatProvider provider)
		{
			return Convert.ToUInt32(GetDoubleValue());
		}

		ulong IConvertible.ToUInt64(IFormatProvider provider)
		{
			return Convert.ToUInt64(GetDoubleValue());
		}

	}

	/// <summary>
	/// Summary description for Class1.
	/// </summary>
	class Class1
	{
		static void Main(string[] args)
		{

			Complex		testComplex = new Complex(4,7);

			WriteObjectInfo(testComplex);
			WriteObjectInfo(Convert.ToBoolean(testComplex));
			WriteObjectInfo(Convert.ToDecimal(testComplex));
			WriteObjectInfo(Convert.ToString(testComplex));

		}

		static void WriteObjectInfo(object testObject)
		{
			TypeCode	typeCode = Type.GetTypeCode( testObject.GetType() );

			switch( typeCode )
			{
				case TypeCode.Boolean:
					Console.WriteLine("Boolean: {0}", testObject);
					break;

				case TypeCode.Double:
					Console.WriteLine("Double: {0}", testObject);
					break;
								
				default:
					Console.WriteLine("{0}: {1}", typeCode.ToString(), testObject);
					break;
			}
		}
	}
}
Public Class Complex : Implements IConvertible
   Private x, y As Double

   Public Sub New(ByVal x As Double, ByVal y As Double)
      Me.x = x
      Me.y = y
   End Sub

   Function GetDoubleValue() As Double
      Return Math.Sqrt((x * x + y * y))
   End Function

   ' The remaining code provides IConvertible method implementations.
   Public Function GetTypeCode() As TypeCode Implements IConvertible.GetTypeCode
      Return TypeCode.Object
   End Function

   Function ToBoolean(ByVal provider As IFormatProvider) As Boolean _
            Implements IConvertible.ToBoolean
      Return x <> 0 OrElse y <> 0
   End Function

   Function ToByte(ByVal provider As IFormatProvider) As Byte Implements IConvertible.ToByte
       Return Convert.ToByte(GetDoubleValue())
   End Function

   Function ToChar(ByVal provider As IFormatProvider) As Char Implements IConvertible.ToChar
      Return Convert.ToChar(GetDoubleValue())
   End Function

   Function ToDateTime(ByVal provider As IFormatProvider) As DateTime Implements IConvertible.ToDateTime
      Return Convert.ToDateTime(GetDoubleValue())
   End Function

   Function ToDecimal(ByVal provider As IFormatProvider) As Decimal Implements IConvertible.ToDecimal
      Return Convert.ToDecimal(GetDoubleValue())
   End Function

   Function ToDouble(ByVal provider As IFormatProvider) As Double Implements IConvertible.ToDouble
      Return GetDoubleValue()
   End Function

   Function ToInt16(ByVal provider As IFormatProvider) As Short Implements IConvertible.ToInt16
      Return Convert.ToInt16(GetDoubleValue())
   End Function

   Function ToInt32(ByVal provider As IFormatProvider) As Integer Implements IConvertible.ToInt32
      Return Convert.ToInt32(GetDoubleValue())
   End Function

   Function ToInt64(ByVal provider As IFormatProvider) As Long Implements IConvertible.ToInt64
      Return Convert.ToInt64(GetDoubleValue())
   End Function

   Function ToSByte(ByVal provider As IFormatProvider) As SByte Implements IConvertible.ToSByte
      Return Convert.ToSByte(GetDoubleValue())
   End Function

   Function ToSingle(ByVal provider As IFormatProvider) As Single Implements IConvertible.ToSingle
      Return Convert.ToSingle(GetDoubleValue())
   End Function

   Overloads Function ToString(ByVal provider As IFormatProvider) As String Implements IConvertible.ToString
      Return String.Format("({0}, {1})", x, y)
   End Function

   Function ToType(ByVal conversionType As Type, ByVal provider As IFormatProvider) As Object Implements IConvertible.ToType
      Return Convert.ChangeType(GetDoubleValue(), conversionType)
   End Function

   Function ToUInt16(ByVal provider As IFormatProvider) As UInt16 Implements IConvertible.ToUInt16
      Return Convert.ToUInt16(GetDoubleValue())
   End Function

   Function ToUInt32(ByVal provider As IFormatProvider) As UInt32 Implements IConvertible.ToUInt32
      Return Convert.ToUInt32(GetDoubleValue())
   End Function

   Function ToUInt64(ByVal provider As IFormatProvider) As UInt64 Implements IConvertible.ToUInt64
      Return Convert.ToUInt64(GetDoubleValue())
   End Function
End Class

Public Module Example
   Sub Main()
      Dim testComplex As New Complex(4, 7)

      WriteObjectInfo(testComplex)
      WriteObjectInfo(Convert.ToBoolean(testComplex))
      WriteObjectInfo(Convert.ToDecimal(testComplex))
      WriteObjectInfo(Convert.ToString(testComplex))
   End Sub

   Sub WriteObjectInfo(ByVal testObject As Object)
      Dim typeCode As TypeCode = Type.GetTypeCode(testObject.GetType())

      Select Case typeCode
         Case typeCode.Boolean
            Console.WriteLine("Boolean: {0}", testObject)

         Case typeCode.Double
            Console.WriteLine("Double: {0}", testObject)

         Case Else
            Console.WriteLine("{0}: {1}", typeCode.ToString(), testObject)
      End Select
   End Sub
End Module

Commenti

Questa interfaccia fornisce metodi per convertire il valore di un'istanza di un tipo di implementazione in un tipo di Common Language Runtime con un valore equivalente.This interface provides methods to convert the value of an instance of an implementing type to a common language runtime type that has an equivalent value. I tipi di Common Language Runtime Booleansono SByte Byte,, Int16, UInt16,, Int32, ,Int64,,, ,Double Single UInt64 UInt32 Decimal,, eString. DateTime CharThe common language runtime types are Boolean, SByte, Byte, Int16, UInt16, Int32, UInt32, Int64, UInt64, Single, Double, Decimal, DateTime, Char, and String.

Se non esiste una conversione significativa in un tipo di Common Language Runtime, viene generata InvalidCastExceptionun'implementazione del metodo di interfaccia particolare.If there is no meaningful conversion to a common language runtime type, then a particular interface method implementation throws InvalidCastException. Se, ad esempio, questa interfaccia viene implementata in un tipo booleano, l' ToDateTime implementazione del metodo genera un'eccezione in quanto non DateTime esiste un equivalente significativo a un tipo booleano.For example, if this interface is implemented on a Boolean type, the implementation of the ToDateTime method throws an exception because there is no meaningful DateTime equivalent to a Boolean type.

Il Common Language Runtime in genere espone IConvertible l'interfaccia tramite Convert la classe.The common language runtime typically exposes the IConvertible interface through the Convert class. Il Common Language Runtime usa anche l' IConvertible interfaccia internamente, nelle implementazioni esplicite dell'interfaccia, per semplificare il codice usato per supportare le Convert conversioni nella classe e i tipi di Common Language Runtime di base.The common language runtime also uses the IConvertible interface internally, in explicit interface implementations, to simplify the code used to support conversions in the Convert class and basic common language runtime types.

Oltre all' IConvertible interfaccia, il .NET Framework fornisce classi denominate convertitori di tipi per la conversione di tipi di dati definiti dall'utente in altri tipi di dati.In addition to the IConvertible interface, the .NET Framework provides classes called type converters for converting user-defined data types to other data types. Per ulteriori informazioni, vedere l'argomento conversione generalizzata dei tipi .For more information, see the Generalized Type Conversion topic.

Note per gli implementatori

Se si implementa l' IConvertible interfaccia, l'implementazione viene chiamata automaticamente ChangeType(Object, Type) dal metodo se il Object parametro è un'istanza del tipo di implementazione e il Type parametro è un Common Language Runtime tipo.If you implement the IConvertible interface, your implementation will be called automatically by the ChangeType(Object, Type) method if the Object parameter is an instance of your implementing type and the Type parameter is a common language runtime type.

La maggior parte dei metodi di conversione ha IFormatProvider un parametro di tipo che rappresenta leCurrentCultureimpostazioni cultura correnti () o impostazioni cultura specifiche.Most conversion methods have a parameter of type IFormatProvider that represents either the current culture (CurrentCulture) or a specific culture. Per la maggior parte delle IConvertible implementazioni dei tipi di base, questo parametro viene ignorato.For the most part, the IConvertible implementations of the base types ignore this parameter. Tuttavia, è possibile scegliere se usarlo nel codice.However, you can choose whether to use it in your code.

Metodi

GetTypeCode() GetTypeCode() GetTypeCode() GetTypeCode()

Restituisce l'oggetto TypeCode per questa istanza.Returns the TypeCode for this instance.

ToBoolean(IFormatProvider) ToBoolean(IFormatProvider) ToBoolean(IFormatProvider) ToBoolean(IFormatProvider)

Converte il valore di questa istanza in un valore Boolean equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent Boolean value using the specified culture-specific formatting information.

ToByte(IFormatProvider) ToByte(IFormatProvider) ToByte(IFormatProvider) ToByte(IFormatProvider)

Converte il valore di questa istanza in un valore intero senza segno a 8 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent 8-bit unsigned integer using the specified culture-specific formatting information.

ToChar(IFormatProvider) ToChar(IFormatProvider) ToChar(IFormatProvider) ToChar(IFormatProvider)

Converte il valore di questa istanza in un carattere Unicode equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent Unicode character using the specified culture-specific formatting information.

ToDateTime(IFormatProvider) ToDateTime(IFormatProvider) ToDateTime(IFormatProvider) ToDateTime(IFormatProvider)

Converte il valore di questa istanza in un oggetto DateTime equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent DateTime using the specified culture-specific formatting information.

ToDecimal(IFormatProvider) ToDecimal(IFormatProvider) ToDecimal(IFormatProvider) ToDecimal(IFormatProvider)

Converte il valore di questa istanza in un numero Decimal equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent Decimal number using the specified culture-specific formatting information.

ToDouble(IFormatProvider) ToDouble(IFormatProvider) ToDouble(IFormatProvider) ToDouble(IFormatProvider)

Converte il valore di questa istanza in un numero in virgola mobile e precisione doppia mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent double-precision floating-point number using the specified culture-specific formatting information.

ToInt16(IFormatProvider) ToInt16(IFormatProvider) ToInt16(IFormatProvider) ToInt16(IFormatProvider)

Converte il valore di questa istanza in un valore intero con segno a 16 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent 16-bit signed integer using the specified culture-specific formatting information.

ToInt32(IFormatProvider) ToInt32(IFormatProvider) ToInt32(IFormatProvider) ToInt32(IFormatProvider)

Converte il valore dell'istanza in un intero con segno a 32 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent 32-bit signed integer using the specified culture-specific formatting information.

ToInt64(IFormatProvider) ToInt64(IFormatProvider) ToInt64(IFormatProvider) ToInt64(IFormatProvider)

Converte il valore dell'istanza in un intero con segno a 64 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent 64-bit signed integer using the specified culture-specific formatting information.

ToSByte(IFormatProvider) ToSByte(IFormatProvider) ToSByte(IFormatProvider) ToSByte(IFormatProvider)

Converte il valore dell'istanza in un intero con segno a 8 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent 8-bit signed integer using the specified culture-specific formatting information.

ToSingle(IFormatProvider) ToSingle(IFormatProvider) ToSingle(IFormatProvider) ToSingle(IFormatProvider)

Converte il valore di questa istanza in un numero in virgola mobile e precisione singola mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent single-precision floating-point number using the specified culture-specific formatting information.

ToString(IFormatProvider) ToString(IFormatProvider) ToString(IFormatProvider) ToString(IFormatProvider)

Converte il valore di questa istanza in un oggetto String equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent String using the specified culture-specific formatting information.

ToType(Type, IFormatProvider) ToType(Type, IFormatProvider) ToType(Type, IFormatProvider) ToType(Type, IFormatProvider)

Converte il valore di questa istanza in un oggetto Object con attributo Type specificato dal valore equivalente, mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an Object of the specified Type that has an equivalent value, using the specified culture-specific formatting information.

ToUInt16(IFormatProvider) ToUInt16(IFormatProvider) ToUInt16(IFormatProvider) ToUInt16(IFormatProvider)

Converte il valore dell'istanza in un intero senza segno a 16 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent 16-bit unsigned integer using the specified culture-specific formatting information.

ToUInt32(IFormatProvider) ToUInt32(IFormatProvider) ToUInt32(IFormatProvider) ToUInt32(IFormatProvider)

Converte il valore dell'istanza in un intero senza segno a 32 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent 32-bit unsigned integer using the specified culture-specific formatting information.

ToUInt64(IFormatProvider) ToUInt64(IFormatProvider) ToUInt64(IFormatProvider) ToUInt64(IFormatProvider)

Converte il valore dell'istanza in un intero senza segno a 64 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura.Converts the value of this instance to an equivalent 64-bit unsigned integer using the specified culture-specific formatting information.

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