C# Exception构造函数代码示例

// 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( ) );
            }
        }
    }
}

// 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( ) );
            }
        }
    }
}

//引入命名空间
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( ) );
         }
     }
 }

// 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( ) );
            }
        }
    }
}