Exception Exception Exception Exception Constructors

Definition

Overloads

Exception() Exception() Exception()

Initializes a new instance of the Exception class.

Exception(String) Exception(String) Exception(String) Exception(String)

Initializes a new instance of the Exception class with a specified error message.

Exception(SerializationInfo, StreamingContext) Exception(SerializationInfo, StreamingContext) Exception(SerializationInfo, StreamingContext) Exception(SerializationInfo, StreamingContext)

Initializes a new instance of the Exception class with serialized data.

Exception(String, Exception) Exception(String, Exception) Exception(String, Exception) Exception(String, Exception)

Initializes a new instance of the Exception class with a specified error message and a reference to the inner exception that is the cause of this exception.

Exception() Exception() Exception()

Initializes a new instance of the Exception class.

public:
 Exception();
public Exception ();
Public Sub New ()

Examples

The following code example derives an Exception that uses a predefined message. The code demonstrates the use of the parameterless constructor for the derived class and the base Exception class.

// Example for the Exception( ) constructor.
using namespace System;

namespace NDP_UE_CPP
{

   // Derive an exception with a predefined message.
   public ref class NotEvenException: public Exception
   {
   public:
      NotEvenException()
         : Exception( "The argument to a function requiring "
      "even input is not divisible by 2." )
      {}

   };


   // Half throws a base exception if the input is not even.
   int Half( int input )
   {
      if ( input % 2 != 0 )
            throw gcnew Exception;
      else
            return input / 2;
   }


   // Half2 throws a derived exception if the input is not even.
   int Half2( int input )
   {
      if ( input % 2 != 0 )
            throw gcnew NotEvenException;
      else
            return input / 2;
   }


   // CalcHalf calls Half and catches any thrown exceptions.
   void CalcHalf( int input )
   {
      try
      {
         int halfInput = Half( input );
         Console::WriteLine( "Half of {0} is {1}.", input, halfInput );
      }
      catch ( Exception^ ex ) 
      {
         Console::WriteLine( ex->ToString() );
      }

   }


   // CalcHalf2 calls Half2 and catches any thrown exceptions.
   void CalcHalf2( int input )
   {
      try
      {
         int halfInput = Half2( input );
         Console::WriteLine( "Half of {0} is {1}.", input, halfInput );
      }
      catch ( Exception^ ex ) 
      {
         Console::WriteLine( ex->ToString() );
      }

   }

}

int main()
{
   Console::WriteLine( "This example of the Exception( ) constructor "
   "generates the following output." );
   Console::WriteLine( "\nHere, an exception is thrown using the \n"
   "parameterless constructor of the base class.\n" );
   NDP_UE_CPP::CalcHalf( 12 );
   NDP_UE_CPP::CalcHalf( 15 );
   Console::WriteLine( "\nHere, an exception is thrown using the \n"
   "parameterless constructor of a derived class.\n" );
   NDP_UE_CPP::CalcHalf2( 24 );
   NDP_UE_CPP::CalcHalf2( 27 );
}

/*
This example of the Exception( ) constructor generates the following output.

Here, an exception is thrown using the
parameterless constructor of the base class.

Half of 12 is 6.
System.Exception: Exception of type System.Exception was thrown.
   at NDP_UE_CPP.Half(Int32 input)
   at NDP_UE_CPP.CalcHalf(Int32 input)

Here, an exception is thrown using the
parameterless constructor of a derived class.

Half of 24 is 12.
NDP_UE_CPP.NotEvenException: The argument to a function requiring even input is
 not divisible by 2.
   at NDP_UE_CPP.Half2(Int32 input)
   at NDP_UE_CPP.CalcHalf2(Int32 input)
*/
// Example for the Exception( ) constructor.
using System;

namespace NDP_UE_CS
{
    // Derive an exception with a predefined message.
    class NotEvenException : Exception
    {
        public NotEvenException( ) :
            base( "The argument to a function requiring " +
                "even input is not divisible by 2." )
        { }
    }

    class NewExceptionDemo 
    {
        public static void Main() 
        {
            Console.WriteLine( 
                "This example of the Exception( ) constructor " +
                "generates the following output." );
            Console.WriteLine( 
                "\nHere, an exception is thrown using the \n" +
                "parameterless constructor of the base class.\n" );

            CalcHalf( 12 );
            CalcHalf( 15 );

            Console.WriteLine( 
                "\nHere, an exception is thrown using the \n" +
                "parameterless constructor of a derived class.\n" );

            CalcHalf2( 24 );
            CalcHalf2( 27 );
        }
    	
        // Half throws a base exception if the input is not even.
        static int Half( int input )
        {
            if( input % 2 != 0 )
                throw new Exception( );

            else return input / 2;
        }

        // Half2 throws a derived exception if the input is not even.
        static int Half2( int input )
        {
            if( input % 2 != 0 )
                throw new NotEvenException( );

            else return input / 2;
        }

        // CalcHalf calls Half and catches any thrown exceptions.
        static void CalcHalf(int input )
        {
            try
            {
                int halfInput = Half( input );
                Console.WriteLine( 
                    "Half of {0} is {1}.", input, halfInput );
            }
            catch( Exception ex )
            {
                Console.WriteLine( ex.ToString( ) );
            }
        }

        // CalcHalf2 calls Half2 and catches any thrown exceptions.
        static void CalcHalf2(int input )
        {
            try
            {
                int halfInput = Half2( input );
                Console.WriteLine( 
                    "Half of {0} is {1}.", input, halfInput );
            }
            catch( Exception ex )
            {
                Console.WriteLine( ex.ToString( ) );
            }
        }
    }
}

/*
This example of the Exception( ) constructor generates the following output.

Here, an exception is thrown using the
parameterless constructor of the base class.

Half of 12 is 6.
System.Exception: Exception of type System.Exception was thrown.
   at NDP_UE_CS.NewExceptionDemo.Half(Int32 input)
   at NDP_UE_CS.NewExceptionDemo.CalcHalf(Int32 input)

Here, an exception is thrown using the
parameterless constructor of a derived class.

Half of 24 is 12.
NDP_UE_CS.NotEvenException: The argument to a function requiring even input is
not divisible by 2.
   at NDP_UE_CS.NewExceptionDemo.Half2(Int32 input)
   at NDP_UE_CS.NewExceptionDemo.CalcHalf2(Int32 input)
*/
' Example for the Exception( ) constructor.
Imports System
Imports Microsoft.VisualBasic

Namespace NDP_UE_VB

    ' Derive an exception with a predefined message.
    Class NotEvenException
        Inherits Exception
           
        Public Sub New( )
            MyBase.New( _
                "The argument to a function requiring " & _
                "even input is not divisible by 2." )
        End Sub ' New
    End Class ' NotEvenException

    Module NewExceptionDemo
       
        Sub Main( )
            Console.WriteLine( _
                "This example of the Exception( ) constructor " & _
                "generates the following output." )
            Console.WriteLine( vbCrLf & _
                "Here, an exception is thrown using the " & vbCrLf & _
                "parameterless constructor of the base class." & _
                vbCrLf )

            CalcHalf( 12 )
            CalcHalf( 15 )
              
            Console.WriteLine(vbCrLf & _
                "Here, an exception is thrown using the " & vbCrLf & _
                "parameterless constructor of a derived class." & _
                vbCrLf )

            CalcHalf2( 24 )
            CalcHalf2( 27 )
        End Sub ' Main
           
        ' Half throws a base exception if the input is not even.
        Function Half( input As Integer ) As Integer

            If input Mod 2 <> 0 Then
                Throw New Exception( )
            Else
                Return input / 2
            End If
        End Function ' Half
            
        ' Half2 throws a derived exception if the input is not even.
        Function Half2( input As Integer ) As Integer

            If input Mod 2 <> 0 Then
                Throw New NotEvenException( )
            Else
                Return input / 2
            End If
        End Function ' Half2
            
        ' CalcHalf calls Half and catches any thrown exceptions.
        Sub CalcHalf( input As Integer )

            Try
                Dim halfInput As Integer = Half( input )
                Console.WriteLine( _
                    "Half of {0} is {1}.", input, halfInput )

            Catch ex As Exception
                Console.WriteLine( ex.ToString( ) )
            End Try
        End Sub ' CalcHalf
           
        ' CalcHalf2 calls Half2 and catches any thrown exceptions.
        Sub CalcHalf2( input As Integer )

            Try
                Dim halfInput As Integer = Half2( input )
                Console.WriteLine( _
                    "Half of {0} is {1}.", input, halfInput )

            Catch ex As Exception
                Console.WriteLine( ex.ToString( ) )
            End Try
        End Sub ' CalcHalf2

    End Module ' NewExceptionDemo
End Namespace ' NDP_UE_VB

' This example of the Exception( ) constructor generates the following output.
' 
' Here, an exception is thrown using the
' parameterless constructor of the base class.
' 
' Half of 12 is 6.
' System.Exception: Exception of type System.Exception was thrown.
'    at NDP_UE_VB.NewExceptionDemo.Half(Int32 input)
'    at NDP_UE_VB.NewExceptionDemo.CalcHalf(Int32 input)
' 
' Here, an exception is thrown using the
' parameterless constructor of a derived class.
' 
' Half of 24 is 12.
' NDP_UE_VB.NotEvenException: The argument to a function requiring even input i
' s not divisible by 2.
'    at NDP_UE_VB.NewExceptionDemo.Half2(Int32 input)
'    at NDP_UE_VB.NewExceptionDemo.CalcHalf2(Int32 input)

Remarks

This constructor initializes the Message property of the new instance to a system-supplied message that describes the error and takes into account the current system culture.

All the derived classes should provide this default constructor. The following table shows the initial property values for an instance of Exception.

Property Value
InnerException A null reference (Nothing in Visual Basic).
Message A system-supplied localized description.

Exception(String) Exception(String) Exception(String) Exception(String)

Initializes a new instance of the Exception class with a specified error message.

public:
 Exception(System::String ^ message);
public Exception (string message);
new Exception : string -> Exception
Public Sub New (message As String)

Parameters

message
String String String String

The message that describes the error.

Examples

The following code example derives an Exception for a specific condition. The code demonstrates the use of the constructor that takes a caller-specified message as a parameter, for both the derived class and the base Exception class.

// Example for the Exception( String* ) constructor.
using namespace System;

namespace NDP_UE_CPP
{

   // Derive an exception with a specifiable message.
   public ref class NotEvenException: public Exception
   {
   private:
      static String^ notEvenMessage = "The argument to a function requiring "
      "even input is not divisible by 2.";

   public:
      NotEvenException()
         : Exception( notEvenMessage )
      {}

      NotEvenException( String^ auxMessage )
         : Exception( String::Format( "{0} - {1}", auxMessage, notEvenMessage ) )
      {}

   };


   // Half throws a base exception if the input is not even.
   int Half( int input )
   {
      if ( input % 2 != 0 )
            throw gcnew Exception( String::Format( "The argument {0} is not divisible by 2.", input ) );
      else
            return input / 2;
   }


   // Half2 throws a derived exception if the input is not even.
   int Half2( int input )
   {
      if ( input % 2 != 0 )
            throw gcnew NotEvenException( String::Format( "Invalid argument: {0}", input ) );
      else
            return input / 2;
   }


   // CalcHalf calls Half and catches any thrown exceptions.
   void CalcHalf( int input )
   {
      try
      {
         int halfInput = Half( input );
         Console::WriteLine( "Half of {0} is {1}.", input, halfInput );
      }
      catch ( Exception^ ex ) 
      {
         Console::WriteLine( ex->ToString() );
      }

   }


   // CalcHalf2 calls Half2 and catches any thrown exceptions.
   void CalcHalf2( int input )
   {
      try
      {
         int halfInput = Half2( input );
         Console::WriteLine( "Half of {0} is {1}.", input, halfInput );
      }
      catch ( Exception^ ex ) 
      {
         Console::WriteLine( ex->ToString() );
      }

   }

}

int main()
{
   Console::WriteLine( "This example of the Exception( String* )\n"
   "constructor generates the following output." );
   Console::WriteLine( "\nHere, an exception is thrown using the \n"
   "constructor of the base class.\n" );
   NDP_UE_CPP::CalcHalf( 18 );
   NDP_UE_CPP::CalcHalf( 21 );
   Console::WriteLine( "\nHere, an exception is thrown using the \n"
   "constructor of a derived class.\n" );
   NDP_UE_CPP::CalcHalf2( 30 );
   NDP_UE_CPP::CalcHalf2( 33 );
}

/*
This example of the Exception( String* )
constructor generates the following output.

Here, an exception is thrown using the
constructor of the base class.

Half of 18 is 9.
System.Exception: The argument 21 is not divisible by 2.
   at NDP_UE_CPP.Half(Int32 input)
   at NDP_UE_CPP.CalcHalf(Int32 input)

Here, an exception is thrown using the
constructor of a derived class.

Half of 30 is 15.
NDP_UE_CPP.NotEvenException: Invalid argument: 33 - The argument to a function
requiring even input is not divisible by 2.
   at NDP_UE_CPP.Half2(Int32 input)
   at NDP_UE_CPP.CalcHalf2(Int32 input)
*/
// Example for the Exception( string ) constructor.
using System;

namespace NDP_UE_CS
{
    // Derive an exception with a specifiable message.
    class NotEvenException : Exception
    {
        const string notEvenMessage = 
            "The argument to a function requiring " +
            "even input is not divisible by 2.";

        public NotEvenException( ) :
            base( notEvenMessage )
        { }

        public NotEvenException( string auxMessage ) :
            base( String.Format( "{0} - {1}", 
                auxMessage, notEvenMessage ) )
        { }
    }

    class NewSExceptionDemo 
    {
        public static void Main() 
        {
            Console.WriteLine( 
                "This example of the Exception( string )\n" +
                "constructor generates the following output." );
            Console.WriteLine( 
                "\nHere, an exception is thrown using the \n" +
                "constructor of the base class.\n" );

            CalcHalf( 18 );
            CalcHalf( 21 );

            Console.WriteLine( 
                "\nHere, an exception is thrown using the \n" +
                "constructor of a derived class.\n" );

            CalcHalf2( 30 );
            CalcHalf2( 33 );
        }
    	
        // Half throws a base exception if the input is not even.
        static int Half( int input )
        {
            if( input % 2 != 0 )
                throw new Exception( String.Format( 
                    "The argument {0} is not divisible by 2.", 
                    input ) );

            else return input / 2;
        }

        // Half2 throws a derived exception if the input is not even.
        static int Half2( int input )
        {
            if( input % 2 != 0 )
                throw new NotEvenException( 
                    String.Format( "Invalid argument: {0}", input ) );

            else return input / 2;
        }

        // CalcHalf calls Half and catches any thrown exceptions.
        static void CalcHalf(int input )
        {
            try
            {
                int halfInput = Half( input );
                Console.WriteLine( 
                    "Half of {0} is {1}.", input, halfInput );
            }
            catch( Exception ex )
            {
                Console.WriteLine( ex.ToString( ) );
            }
        }

        // CalcHalf2 calls Half2 and catches any thrown exceptions.
        static void CalcHalf2(int input )
        {
            try
            {
                int halfInput = Half2( input );
                Console.WriteLine( 
                    "Half of {0} is {1}.", input, halfInput );
            }
            catch( Exception ex )
            {
                Console.WriteLine( ex.ToString( ) );
            }
        }
    }
}

/*
This example of the Exception( string )
constructor generates the following output.

Here, an exception is thrown using the
constructor of the base class.

Half of 18 is 9.
System.Exception: The argument 21 is not divisible by 2.
   at NDP_UE_CS.NewSExceptionDemo.Half(Int32 input)
   at NDP_UE_CS.NewSExceptionDemo.CalcHalf(Int32 input)

Here, an exception is thrown using the
constructor of a derived class.

Half of 30 is 15.
NDP_UE_CS.NotEvenException: Invalid argument: 33 - The argument to a function r
equiring even input is not divisible by 2.
   at NDP_UE_CS.NewSExceptionDemo.Half2(Int32 input)
   at NDP_UE_CS.NewSExceptionDemo.CalcHalf2(Int32 input)
*/
' Example for the Exception( String ) constructor( String ).
Imports System
Imports Microsoft.VisualBasic

Namespace NDP_UE_VB

    ' Derive an exception with a specifiable message.
    Class NotEvenException
        Inherits Exception

        Private Const notEvenMessage As String = _
            "The argument to a function requiring " & _
            "even input is not divisible by 2."
           
        Public Sub New()
            MyBase.New(notEvenMessage)
        End Sub ' New
           
        Public Sub New(auxMessage As String)
            MyBase.New(String.Format("{0} - {1}", _
                auxMessage, notEvenMessage))
        End Sub ' New
    End Class ' NotEvenException

    Module NewSExceptionDemo
       
        Sub Main()
            Console.WriteLine( _
                "This example of the Exception( String )" & vbCrLf & _
                "constructor generates the following output." )
            Console.WriteLine( vbCrLf & _
                "Here, an exception is thrown using the " & vbCrLf & _
                "constructor of the base class." & vbCrLf )

            CalcHalf(18)
            CalcHalf(21)
              
            Console.WriteLine(vbCrLf & _
                "Here, an exception is thrown using the " & vbCrLf & _
                "constructor of a derived class." & vbCrLf )

            CalcHalf2(30)
            CalcHalf2(33)
        End Sub ' Main
           
        ' Half throws a base exception if the input is not even.
        Function Half(input As Integer) As Integer

            If input Mod 2 <> 0 Then
                Throw New Exception( String.Format( _
                    "The argument {0} is not divisible by 2.", _
                    input ) )
            Else
                Return input / 2
            End If
        End Function ' Half
            
        ' Half2 throws a derived exception if the input is not even.
        Function Half2(input As Integer) As Integer

            If input Mod 2 <> 0 Then
                Throw New NotEvenException( _
                    String.Format( "Invalid argument: {0}", input ) )
            Else
                Return input / 2
            End If
        End Function ' Half2
            
        ' CalcHalf calls Half and catches any thrown exceptions.
        Sub CalcHalf(input As Integer)

            Try
                Dim halfInput As Integer = Half(input)
                Console.WriteLine( _
                    "Half of {0} is {1}.", input, halfInput )

            Catch ex As Exception
                Console.WriteLine( ex.ToString( ) )
            End Try
        End Sub ' CalcHalf
           
           
        ' CalcHalf2 calls Half2 and catches any thrown exceptions.
        Sub CalcHalf2( input As Integer )

            Try
                Dim halfInput As Integer = Half2( input )
                Console.WriteLine( _
                    "Half of {0} is {1}.", input, halfInput )

            Catch ex As Exception
                Console.WriteLine( ex.ToString( ) )
            End Try
        End Sub ' CalcHalf2

    End Module ' NewSExceptionDemo
End Namespace ' NDP_UE_VB

' This example of the Exception( String )
' constructor generates the following output.
' 
' Here, an exception is thrown using the
' constructor of the base class.
' 
' Half of 18 is 9.
' System.Exception: The argument 21 is not divisible by 2.
'    at NDP_UE_VB.NewSExceptionDemo.Half(Int32 input)
'    at NDP_UE_VB.NewSExceptionDemo.CalcHalf(Int32 input)
' 
' Here, an exception is thrown using the
' constructor of a derived class.
' 
' Half of 30 is 15.
' NDP_UE_VB.NotEvenException: Invalid argument: 33 - The argument to a function
'  requiring even input is not divisible by 2.
'    at NDP_UE_VB.NewSExceptionDemo.Half2(Int32 input)
'    at NDP_UE_VB.NewSExceptionDemo.CalcHalf2(Int32 input)

Remarks

This constructor initializes the Message property of the new instance by using the message parameter. If the message parameter is null, this is the same as calling the Exception constructor.

The following table shows the initial property values for an instance of Exception.

Property Value
InnerException A null reference (Nothing in Visual Basic).
Message The error message string.

Exception(SerializationInfo, StreamingContext) Exception(SerializationInfo, StreamingContext) Exception(SerializationInfo, StreamingContext) Exception(SerializationInfo, StreamingContext)

Initializes a new instance of the Exception class with serialized data.

protected:
 Exception(System::Runtime::Serialization::SerializationInfo ^ info, System::Runtime::Serialization::StreamingContext context);
protected Exception (System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context);
new Exception : System.Runtime.Serialization.SerializationInfo * System.Runtime.Serialization.StreamingContext -> Exception
Protected Sub New (info As SerializationInfo, context As StreamingContext)

Parameters

info
SerializationInfo SerializationInfo SerializationInfo SerializationInfo

The SerializationInfo that holds the serialized object data about the exception being thrown.

context
StreamingContext StreamingContext StreamingContext StreamingContext

The StreamingContext that contains contextual information about the source or destination.

Exceptions

Examples

The following code example defines a derived serializable Exception class. The code forces a divide-by-0 error and then creates an instance of the derived exception using the (SerializationInfo, StreamingContext) constructor. The code serializes the instance to a file, deserializes the file into a new exception, which it throws, and then catches and displays the exception's data.

#using <System.Runtime.Serialization.Formatters.Soap.dll>

using namespace System;
using namespace System::IO;
using namespace System::Runtime::Serialization;
using namespace System::Runtime::Serialization::Formatters::Soap;

// Define a serializable derived exception class.

[Serializable]
ref class SecondLevelException: public Exception, public ISerializable
{
public:

   // This public constructor is used by class instantiators.
   SecondLevelException( String^ message, Exception^ inner )
      : Exception( message, inner )
   {
      HelpLink = "http://MSDN.Microsoft.com";
      Source = "Exception_Class_Samples";
   }


protected:

   // This protected constructor is used for deserialization.
   SecondLevelException( SerializationInfo^ info, StreamingContext context )
      : Exception( info, context )
   {}


public:

   // GetObjectData performs a custom serialization.
   [System::Security::Permissions::SecurityPermissionAttribute
   (System::Security::Permissions::SecurityAction::LinkDemand, 
   Flags=System::Security::Permissions::SecurityPermissionFlag::SerializationFormatter)]
   virtual void GetObjectData( SerializationInfo^ info, StreamingContext context ) override
   {
      
      // Change the case of two properties, and then use the 
      // method of the base class.
      HelpLink = HelpLink->ToLower();
      Source = Source->ToUpperInvariant();
      Exception::GetObjectData( info, context );
   }

};

int main()
{
   Console::WriteLine( "This example of the Exception constructor "
   "and Exception.GetObjectData\nwith Serialization"
   "Info and StreamingContext parameters "
   "generates \nthe following output.\n" );
   try
   {
      
      // This code forces a division by 0 and catches the 
      // resulting exception.
      try
      {
         int zero = 0;
         int ecks = 1 / zero;
      }
      catch ( Exception^ ex ) 
      {
         
         // Create a new exception to throw again.
         SecondLevelException^ newExcept = gcnew SecondLevelException( "Forced a division by 0 and threw "
         "another exception.",ex );
         Console::WriteLine( "Forced a division by 0, caught the "
         "resulting exception, \n"
         "and created a derived exception:\n" );
         Console::WriteLine( "HelpLink: {0}", newExcept->HelpLink );
         Console::WriteLine( "Source:   {0}", newExcept->Source );
         
         // This FileStream is used for the serialization.
         FileStream^ stream = gcnew FileStream( "NewException.dat",FileMode::Create );
         try
         {
            
            // Serialize the derived exception.
            SoapFormatter^ formatter = gcnew SoapFormatter( nullptr,StreamingContext(StreamingContextStates::File) );
            formatter->Serialize( stream, newExcept );
            
            // Rewind the stream and deserialize the 
            // exception.
            stream->Position = 0;
            SecondLevelException^ deserExcept = dynamic_cast<SecondLevelException^>(formatter->Deserialize( stream ));
            Console::WriteLine( "\nSerialized the exception, and then "
            "deserialized the resulting stream "
            "into a \nnew exception. "
            "The deserialization changed the case "
            "of certain properties:\n" );
            
            // Throw the deserialized exception again.
            throw deserExcept;
         }
         catch ( SerializationException^ se ) 
         {
            Console::WriteLine( "Failed to serialize: {0}", se->ToString() );
         }
         finally
         {
            stream->Close();
         }

      }

   }
   catch ( Exception^ ex ) 
   {
      Console::WriteLine( "HelpLink: {0}", ex->HelpLink );
      Console::WriteLine( "Source:   {0}", ex->Source );
      Console::WriteLine();
      Console::WriteLine( ex->ToString() );
   }

}

/*
This example of the Exception constructor and Exception.GetObjectData
with SerializationInfo and StreamingContext parameters generates
the following output.

Forced a division by 0, caught the resulting exception,
and created a derived exception:

HelpLink: http://MSDN.Microsoft.com
Source:   Exception_Class_Samples

Serialized the exception, and then deserialized the resulting stream into a
new exception. The deserialization changed the case of certain properties:

HelpLink: http://msdn.microsoft.com
Source:   EXCEPTION_CLASS_SAMPLES

SecondLevelException: Forced a division by 0 and threw another exception. ---> S
ystem.DivideByZeroException: Attempted to divide by zero.
   at main()
   --- End of inner exception stack trace ---
   at main()

*/
using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Soap;
using System.Security.Permissions;

 // Define a serializable derived exception class.
 [Serializable()]
 class SecondLevelException : Exception, ISerializable
 {
     // This public constructor is used by class instantiators.
     public SecondLevelException( string message, Exception inner ) :
         base( message, inner )
     {
         HelpLink = "http://MSDN.Microsoft.com";
         Source = "Exception_Class_Samples";
     }

     // This protected constructor is used for deserialization.
     protected SecondLevelException( SerializationInfo info, 
         StreamingContext context ) :
             base( info, context )
     { }

     // GetObjectData performs a custom serialization.
     [SecurityPermissionAttribute(SecurityAction.Demand,SerializationFormatter=true)]
     public override void GetObjectData( SerializationInfo info, 
         StreamingContext context ) 
     {
         // Change the case of two properties, and then use the 
         // method of the base class.
         HelpLink = HelpLink.ToLower( );
         Source = Source.ToUpperInvariant();

         base.GetObjectData( info, context );
     }
 }

 class SerializationDemo 
 {
     public static void Main() 
     {
         Console.WriteLine( 
             "This example of the Exception constructor " +
             "and Exception.GetObjectData\nwith Serialization" +
             "Info and StreamingContext parameters " +
             "generates \nthe following output.\n" );

         try
         {
             // This code forces a division by 0 and catches the 
             // resulting exception.
             try
             {
                 int  zero = 0;
                 int  ecks = 1 / zero;
             }
             catch( Exception ex )
             {
                 // Create a new exception to throw again.
                 SecondLevelException newExcept =
                     new SecondLevelException( 
                         "Forced a division by 0 and threw " +
                         "another exception.", ex );

                 Console.WriteLine( 
                     "Forced a division by 0, caught the " +
                     "resulting exception, \n" +
                     "and created a derived exception:\n" );
                 Console.WriteLine( "HelpLink: {0}", 
                     newExcept.HelpLink );
                 Console.WriteLine( "Source:   {0}", 
                     newExcept.Source );

                 // This FileStream is used for the serialization.
                 FileStream stream = 
                     new FileStream( "NewException.dat", 
                         FileMode.Create );

                 try
                 {
                     // Serialize the derived exception.
                     SoapFormatter formatter = 
                         new SoapFormatter( null,
                             new StreamingContext( 
                                 StreamingContextStates.File ) );
                     formatter.Serialize( stream, newExcept );

                     // Rewind the stream and deserialize the 
                     // exception.
                     stream.Position = 0;
                     SecondLevelException deserExcept = 
                         (SecondLevelException)
                             formatter.Deserialize( stream );

                     Console.WriteLine( 
                         "\nSerialized the exception, and then " +
                         "deserialized the resulting stream " +
                         "into a \nnew exception. " +
                         "The deserialization changed the case " +
                         "of certain properties:\n" );
                     
                     // Throw the deserialized exception again.
                     throw deserExcept;
                 }
                 catch( SerializationException se )
                 {
                     Console.WriteLine( "Failed to serialize: {0}", 
                         se.ToString( ) );
                 }
                 finally
                 {
                     stream.Close( );
                 }
             }
         }
         catch( Exception ex )
         {
             Console.WriteLine( "HelpLink: {0}", ex.HelpLink );
             Console.WriteLine( "Source:   {0}", ex.Source );

             Console.WriteLine( );
             Console.WriteLine( ex.ToString( ) );
         }
     }
 }
/*
This example displays the following output.

Forced a division by 0, caught the resulting exception,
and created a derived exception:

HelpLink: http://MSDN.Microsoft.com
Source:   Exception_Class_Samples

Serialized the exception, and then deserialized the resulting stream into a
new exception. The deserialization changed the case of certain properties:

HelpLink: http://msdn.microsoft.com
Source:   EXCEPTION_CLASS_SAMPLES

NDP_UE_CS.SecondLevelException: Forced a division by 0 and threw another except
ion. ---> System.DivideByZeroException: Attempted to divide by zero.
   at NDP_UE_CS.SerializationDemo.Main()
   --- End of inner exception stack trace ---
   at NDP_UE_CS.SerializationDemo.Main()
*/
' If compiling with the Visual Basic compiler (vbc.exe) from the command
' prompt, be sure to add the following switch:
'    /reference:System.Runtime.Serialization.Formatters.Soap.dll 
Imports System.IO
Imports System.Runtime.Serialization
Imports System.Runtime.Serialization.Formatters.Soap
Imports System.Security.Permissions

 ' Define a serializable derived exception class.
 <Serializable()>  _
 Class SecondLevelException
     Inherits Exception

     ' This public constructor is used by class instantiators.
     Public Sub New( message As String, inner As Exception )
         MyBase.New( message, inner )

         HelpLink = "http://MSDN.Microsoft.com"
         Source = "Exception_Class_Samples"
     End Sub

     ' This protected constructor is used for deserialization.
     Protected Sub New( info As SerializationInfo, _
         context As StreamingContext )
             MyBase.New( info, context )
     End Sub

     ' GetObjectData performs a custom serialization.
     <SecurityPermissionAttribute(SecurityAction.Demand, _
                                  SerializationFormatter:=True)> _
     Overrides Sub GetObjectData( info As SerializationInfo, _
         context As StreamingContext)

         ' Change the case of two properties, and then use the
         ' method of the base class.
         HelpLink = HelpLink.ToLower()
         Source = Source.ToUpperInvariant()

         MyBase.GetObjectData(info, context)
     End Sub
 End Class

 Module SerializationDemo

     Sub Main()
         Console.WriteLine( _
             "This example of the Exception constructor " & _
             "and Exception.GetObjectData " & vbCrLf & _
             "with SerializationInfo and StreamingContext " & _
             "parameters generates " & vbCrLf & _
             "the following output." & vbCrLf )

         ' This code forces a division by 0 and catches the
         ' resulting exception.
         Try
             Try
                 Dim zero As Integer = 0
                 Dim ecks As Integer = 1 \ zero

             ' Create a new exception to throw again.
             Catch ex As Exception

                 Dim newExcept As New SecondLevelException( _
                     "Forced a division by 0 and threw " & _
                     "another exception.", ex )

                 Console.WriteLine( _
                     "Forced a division by 0, caught the " & _
                     "resulting exception, " & vbCrLf & _
                     "and created a derived exception:" & vbCrLf )
                 Console.WriteLine( "HelpLink: {0}", _
                     newExcept.HelpLink )
                 Console.WriteLine( "Source:   {0}", _
                     newExcept.Source )

                 ' This FileStream is used for the serialization.
                 Dim stream As New FileStream( _
                     "NewException.dat", FileMode.Create )

                 ' Serialize the derived exception.
                 Try
                     Dim formatter As New SoapFormatter( Nothing, _
                         New StreamingContext( _
                             StreamingContextStates.File ) )
                     formatter.Serialize( stream, newExcept )

                     ' Rewind the stream and deserialize the
                     ' exception.
                     stream.Position = 0
                     Dim deserExcept As SecondLevelException = _
                         CType( formatter.Deserialize( stream ), _
                             SecondLevelException )

                     Console.WriteLine( vbCrLf & _
                         "Serialized the exception, and then " & _
                         "deserialized the resulting stream " & _
                         "into a " & vbCrLf & "new exception. " & _
                         "The deserialization changed the case " & _
                         "of certain properties:" & vbCrLf )

                     ' Throw the deserialized exception again.
                     Throw deserExcept

                 Catch se As SerializationException
                     Console.WriteLine( "Failed to serialize: {0}", _
                         se.ToString( ) )

                 Finally
                     stream.Close( )
                 End Try
             End Try
         Catch ex As Exception
             Console.WriteLine( "HelpLink: {0}", ex.HelpLink )
             Console.WriteLine( "Source:   {0}", ex.Source )

             Console.WriteLine( )
             Console.WriteLine( ex.ToString( ) )
         End Try
     End Sub
 End Module
' This example displays the following output:
' 
' Forced a division by 0, caught the resulting exception,
' and created a derived exception:
' 
' HelpLink: http://MSDN.Microsoft.com
' Source:   Exception_Class_Samples
' 
' Serialized the exception, and then deserialized the resulting stream into a
' new exception. The deserialization changed the case of certain properties:
' 
' HelpLink: http://msdn.microsoft.com
' Source:   EXCEPTION_CLASS_SAMPLES
' 
' NDP_UE_VB.SecondLevelException: Forced a division by 0 and threw another exce
' ption. ---> System.DivideByZeroException: Attempted to divide by zero.
'    at NDP_UE_VB.SerializationDemo.Main()
'    --- End of inner exception stack trace ---
'    at NDP_UE_VB.SerializationDemo.Main()

Remarks

This constructor is called during deserialization to reconstitute the exception object transmitted over a stream. For more information, see XML and SOAP Serialization.

See also

Exception(String, Exception) Exception(String, Exception) Exception(String, Exception) Exception(String, Exception)

Initializes a new instance of the Exception class with a specified error message and a reference to the inner exception that is the cause of this exception.

public:
 Exception(System::String ^ message, Exception ^ innerException);
public Exception (string message, Exception innerException);
new Exception : string * Exception -> Exception
Public Sub New (message As String, innerException As Exception)

Parameters

message
String String String String

The error message that explains the reason for the exception.

innerException
Exception Exception Exception Exception

The exception that is the cause of the current exception, or a null reference (Nothing in Visual Basic) if no inner exception is specified.

Examples

The following code example derives an Exception for a specific condition. The code demonstrates the use of the constructor that takes a message and an inner exception as parameters, for both the derived class and the base Exception class.

// Example for the Exception( String*, Exception* ) constructor.
using namespace System;

namespace NDP_UE_CPP
{

   // Derive an exception with a specifiable message and inner exception.
   public ref class LogTableOverflowException: public Exception
   {
   private:
      static String^ overflowMessage =  "The log table has overflowed.";

   public:
      LogTableOverflowException()
         : Exception( overflowMessage )
      {}

      LogTableOverflowException( String^ auxMessage )
         : Exception( String::Format( "{0} - {1}", overflowMessage, auxMessage ) )
      {}

      LogTableOverflowException( String^ auxMessage, Exception^ inner )
         : Exception( String::Format( "{0} - {1}", overflowMessage, auxMessage ), inner )
      {}

   };

   public ref class LogTable
   {
   public:
      LogTable( int numElements )
      {
         logArea = gcnew array<String^>(numElements);
         elemInUse = 0;
      }


   protected:
      array<String^>^logArea;
      int elemInUse;

   public:

      // The AddRecord method throws a derived exception 
      // if the array bounds exception is caught.
      int AddRecord( String^ newRecord )
      {
         try
         {
            logArea[ elemInUse ] = newRecord;
            return elemInUse++;
         }
         catch ( Exception^ ex ) 
         {
            throw gcnew LogTableOverflowException( String::Format( "Record \"{0}\" was not logged.", newRecord ),ex );
         }

      }

   };


   // Create a log table and force an overflow.
   void ForceOverflow()
   {
      LogTable^ log = gcnew LogTable( 4 );
      try
      {
         for ( int count = 1; ; count++ )
         {
            log->AddRecord( String::Format( "Log record number {0}", count ) );

         }
      }
      catch ( Exception^ ex ) 
      {
         Console::WriteLine( ex->ToString() );
      }

   }

}

int main()
{
   Console::WriteLine( "This example of the Exception( String*, Exception* )\n"
   "constructor generates the following output." );
   Console::WriteLine( "\nExample of a derived exception "
   "that references an inner exception:\n" );
   NDP_UE_CPP::ForceOverflow();
}

/*
This example of the Exception( String*, Exception* )
constructor generates the following output.

Example of a derived exception that references an inner exception:

NDP_UE_CPP.LogTableOverflowException: The log table has overflowed. - Record "L
og record number 5" was not logged. ---> System.IndexOutOfRangeException: Index
 was outside the bounds of the array.
   at NDP_UE_CPP.LogTable.AddRecord(String newRecord)
   --- End of inner exception stack trace ---
   at NDP_UE_CPP.LogTable.AddRecord(String newRecord)
   at NDP_UE_CPP.ForceOverflow()
*/
// Example for the Exception( string, Exception ) constructor.
using System;

namespace NDP_UE_CS
{
    // Derive an exception with a specifiable message and inner exception.
    class LogTableOverflowException : Exception
    {
        const string overflowMessage = 
            "The log table has overflowed.";

        public LogTableOverflowException( ) :
            base( overflowMessage )
        { }

        public LogTableOverflowException( string auxMessage ) :
            base( String.Format( "{0} - {1}", 
                overflowMessage, auxMessage ) )
        { }

        public LogTableOverflowException( 
            string auxMessage, Exception inner ) :
                base( String.Format( "{0} - {1}", 
                    overflowMessage, auxMessage ), inner )
        { }
    }

    class LogTable
    {
        public LogTable( int numElements )
        {
            logArea = new string[ numElements ];
            elemInUse = 0;
        }

        protected string[ ] logArea;
        protected int       elemInUse;

        // The AddRecord method throws a derived exception 
        // if the array bounds exception is caught.
        public    int       AddRecord( string newRecord )
        {
            try
            {
                logArea[ elemInUse ] = newRecord;
                return elemInUse++;
            }
            catch( Exception ex )
            {
                throw new LogTableOverflowException( 
                    String.Format( "Record \"{0}\" was not logged.", 
                        newRecord ), ex );
            }
        }
    }

    class OverflowDemo 
    {
        // Create a log table and force an overflow.
        public static void Main() 
        {
            LogTable log = new LogTable( 4 );

            Console.WriteLine( 
                "This example of the Exception( string, Exception )" +
                "\nconstructor generates the following output." );
            Console.WriteLine( 
                "\nExample of a derived exception " +
                "that references an inner exception:\n" );
            try
            {
                for( int count = 1; ; count++ )
                {
                    log.AddRecord( 
                        String.Format( 
                            "Log record number {0}", count ) );
                }
            }
            catch( Exception ex )
            {
                Console.WriteLine( ex.ToString( ) );
            }
        }
    }
}

/*
This example of the Exception( string, Exception )
constructor generates the following output.

Example of a derived exception that references an inner exception:

NDP_UE_CS.LogTableOverflowException: The log table has overflowed. - Record "Lo
g record number 5" was not logged. ---> System.IndexOutOfRangeException: Index
was outside the bounds of the array.
   at NDP_UE_CS.LogTable.AddRecord(String newRecord)
   --- End of inner exception stack trace ---
   at NDP_UE_CS.LogTable.AddRecord(String newRecord)
   at NDP_UE_CS.OverflowDemo.Main()
*/
' Sample for Exception( String, Exception ) constructor.
Imports System
Imports Microsoft.VisualBasic

Namespace NDP_UE_VB

    ' Derive an exception with a specifiable message and inner exception.
    Class LogTableOverflowException
        Inherits Exception

        Private Const overflowMessage As String = _
            "The log table has overflowed."
           
        Public Sub New( )
            MyBase.New( overflowMessage )
        End Sub ' New
           
        Public Sub New( auxMessage As String )
            MyBase.New( String.Format( "{0} - {1}", _
                overflowMessage, auxMessage ) )
        End Sub ' New
           
        Public Sub New( auxMessage As String, inner As Exception )
            MyBase.New( String.Format( "{0} - {1}", _
                overflowMessage, auxMessage ), inner )
        End Sub ' New
    End Class ' LogTableOverflowException

    Class LogTable
       
        Public Sub New( numElements As Integer )
            logArea = New String( numElements ) { }
            elemInUse = 0
        End Sub ' New
           
        Protected logArea( ) As String
        Protected elemInUse As Integer
           
        ' The AddRecord method throws a derived exception 
        ' if the array bounds exception is caught.
        Public Function AddRecord( newRecord As String ) As Integer

            Try
                Dim curElement as Integer = elemInUse
                logArea( elemInUse ) = newRecord
                elemInUse += 1
                Return curElement

            Catch ex As Exception
                Throw New LogTableOverflowException( String.Format( _
                    "Record ""{0}"" was not logged.", newRecord ), ex )
            End Try
        End Function ' AddRecord
        End Class ' LogTable

        Module OverflowDemo
           
        ' Create a log table and force an overflow.
        Sub Main()
            Dim log As New LogTable(4)
              
            Console.WriteLine( _
                "This example of the Exception( String, Exception )" & _
                vbCrLf & "constructor generates the following output." )
            Console.WriteLine( vbCrLf & _
                "Example of a derived exception " & vbCrLf & _
                "that references an inner exception:" & vbCrLf )
            Try
                Dim count As Integer = 0
                 
                Do
                    log.AddRecord( _
                        String.Format( _
                            "Log record number {0}", count ) )
                    count += 1
                Loop

            Catch ex As Exception
                Console.WriteLine( ex.ToString( ) )
            End Try
        End Sub ' Main

    End Module ' OverflowDemo
End Namespace ' NDP_UE_VB

' This example of the Exception( String, Exception )
' constructor generates the following output.
' 
' Example of a derived exception
' that references an inner exception:
' 
' NDP_UE_VB.LogTableOverflowException: The log table has overflowed. - Record "
' Log record number 5" was not logged. ---> System.IndexOutOfRangeException: In
' dex was outside the bounds of the array.
'    at NDP_UE_VB.LogTable.AddRecord(String newRecord)
'    --- End of inner exception stack trace ---
'    at NDP_UE_VB.LogTable.AddRecord(String newRecord)
'    at NDP_UE_VB.OverflowDemo.Main()

Remarks

An exception that is thrown as a direct result of a previous exception should include a reference to the previous exception in the InnerException property. The InnerException property returns the same value that is passed into the constructor, or a null reference (Nothing in Visual Basic) if the InnerException property does not supply the inner exception value to the constructor.

The following table shows the initial property values for an instance of Exception.

Property Value
InnerException The inner exception reference.
Message The error message string.

Applies to