Manually throw an exception

image_pdfimage_print

   

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Manually throw an exception. 
 
using System; 
 
public class ThrowDemo { 
  public static void Main() { 
    try { 
      Console.WriteLine("Before throw."); 
      throw new DivideByZeroException(); 
    } 
    catch (DivideByZeroException) { 
      // catch the exception 
      Console.WriteLine("Exception caught."); 
    } 
    Console.WriteLine("After try/catch block."); 
  } 
}


           
          


Let the C# runtime system handle the error

image_pdfimage_print

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Let the C# runtime system handle the error.

using System;

public class NotHandled {
public static void Main() {
int[] nums = new int[4];

Console.WriteLine(“Before exception is generated.”);

// Generate an index out-of-bounds exception.
for(int i=0; i < 10; i++) { nums[i] = i; Console.WriteLine("nums[{0}]: {1}", i, nums[i]); } } } [/csharp]

Demonstrates rethrowing an exception from a method

image_pdfimage_print

   

/*
C# Programming Tips &amp; Techniques
by Charles Wright, Kris Jamsa

Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/

//  Rethrow.cs -- Demonstrates rethrowing an exception from a method.
//
//                Compile this program with the following command line:
//                    C:>csc Rethrow.cs
//
namespace nsRethrow
{
    using System;
    using System.IO;
    
    public class Rethrow
    {
        static public void Main ()
        {
            while (true)
            {
                Console.Write ("Please enter a file name (return to exit): ");
                string FileName = Console.ReadLine ();
                if (FileName.Length == 0)
                    break;
                try
                {
                    ReadFile (FileName);
                    break;
                }
                catch (IOException e)
                {
                    if (e is FileNotFoundException)
                        Console.WriteLine ("The file " + FileName + " was not found");
                }
                catch (Exception e)
                {
                    Console.WriteLine (e.Message + "
");
                    break;
                }
            }
        }
        static public void ReadFile (string FileName)
        {
            FileStream strm;
            StreamReader reader;
            try
            {
                strm = new FileStream (FileName, FileMode.Open);
                reader = new StreamReader (strm);
                string str = reader.ReadToEnd ();
                Console.WriteLine (str);
            }
            catch (IOException e)
            {
                // If file not found, go back and get another name
                if (e is FileNotFoundException)
                    throw (e);
                // Code here to handle other IOException classes
                Console.WriteLine (e.Message);
                throw (new IOException());
            }
        }
    }
}


           
          


illustrates creating and throwing an exception object

image_pdfimage_print

   

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/

/*
  Example13_8.cs illustrates creating and
  throwing an exception object
*/

using System;

public class Example13_8
{

  public static void Main()
  {

    try
    {

      // create a new Exception object, passing a string
      // for the Message property to the constructor
      Exception myException = new Exception("myException");

      // set the HelpLink and Source properties
      myException.HelpLink = "See the Readme.txt file";
      myException.Source = "My Example13_8 Program";

      // throw the Exception object
      throw myException;

    }
    catch (Exception e)
    {

      // display the exception object&#039;s properties
      Console.WriteLine("HelpLink = " + e.HelpLink);
      Console.WriteLine("Message = " + e.Message);
      Console.WriteLine("Source = " + e.Source);
      Console.WriteLine("StackTrace = " + e.StackTrace);
      Console.WriteLine("TargetSite = " + e.TargetSite);

    }

  }

}

           
          


Exception throw and catch 2

image_pdfimage_print

   

/*
Learning C# 
by Jesse Liberty

Publisher: O&#039;Reilly 
ISBN: 0596003765
*/
 using System;

 namespace ExceptionHandling
 {
    public class TesterExceptionHandling3
    {

       static void Main()
       {
           Console.WriteLine("Enter Main...");
           TesterExceptionHandling3 t = new TesterExceptionHandling3();
           t.Run();
           Console.WriteLine("Exit Main...");
       }
       public void Run()
       {
           Console.WriteLine("Enter Run...");
           Func1();
           Console.WriteLine("Exit Run...");
       }


        public void Func1()
        {
            Console.WriteLine("Enter Func1...");
            try
            {
                Console.WriteLine("Entering try block...");
                Func2();
                Console.WriteLine("Exiting try block...");
            }
            catch
            {
                Console.WriteLine("Exception caught and handled!");
            }
            Console.WriteLine("Exit Func1...");
        }

        public void Func2()
        {
            Console.WriteLine("Enter Func2...");
            throw new System.Exception();
            Console.WriteLine("Exit Func2...");
        }
    }
 }


           
          


Exception throw and catch

image_pdfimage_print

   

/*
Learning C# 
by Jesse Liberty

Publisher: O&#039;Reilly 
ISBN: 0596003765
*/

 using System;

 namespace ExceptionHandling
 {
    public class TesterExceptionHandling2
    {
       static void Main()
       {
           Console.WriteLine("Enter Main...");
           TesterExceptionHandling2 t = new TesterExceptionHandling2();
           t.Run();
           Console.WriteLine("Exit Main...");
       }
       public void Run()
       {
           Console.WriteLine("Enter Run...");
           Func1();
           Console.WriteLine("Exit Run...");
       }


        public void Func1()
        {
            Console.WriteLine("Enter Func1...");
            Func2();
            Console.WriteLine("Exit Func1...");
        }

        public void Func2()
        {
            Console.WriteLine("Enter Func2...");
            try
            {
                Console.WriteLine("Entering try block...");
                throw new System.Exception();
                Console.WriteLine("Exiting try block...");
            }
            catch
            {
                Console.WriteLine("Exception caught and handled!");
            }
            Console.WriteLine("Exit Func2...");
        }
    }
 }

           
          


Exception throws

image_pdfimage_print

   

/*
Learning C# 
by Jesse Liberty

Publisher: O&#039;Reilly 
ISBN: 0596003765
*/

 using System;

 namespace ExceptionHandling
 {
    public class TesterExceptionHandling1
    {

       static void Main()
       {
           Console.WriteLine("Enter Main...");
           TesterExceptionHandling1 t = new TesterExceptionHandling1();
           t.Run();
           Console.WriteLine("Exit Main...");
       }
       public void Run()
       {
           Console.WriteLine("Enter Run...");
           Func1();
           Console.WriteLine("Exit Run...");
       }

        public void Func1()
        {
            Console.WriteLine("Enter Func1...");
            Func2();
            Console.WriteLine("Exit Func1...");
        }

        public void Func2()
        {
            Console.WriteLine("Enter Func2...");
            throw new System.Exception();
            Console.WriteLine("Exit Func2...");
        }

    }
 }