Wrong line number on stack trace

Question

I have this code

try
{
  //AN EXCEPTION IS GENERATED HERE!!!
}
catch  
{
   SqlService.RollbackTransaction();
   throw;
}

Code above is ca

Answer 1

As of .NET Framework 4.5 you can use the ExceptionDispatchInfo class to do this without the need for another method. For example, borrowing the code from Hans' excellent answer, when you just use throw, like this:

using System;

class Program {
    static void Main(string[] args) {
        try {
            Test();
        }
        catch (Exception ex) {
            Console.WriteLine(ex.ToString());
        }
        Console.ReadLine();
    }
    static void Test() {
        try {
            throw new ArgumentException();  // Line 15
        }
        catch {
            throw;                          // Line 18
        }
    }
}

It outputs this:

System.ArgumentException: Value does not fall within the expected range.
   at Program.Test() in Program.cs:line 18
   at Program.Main(String[] args) in Program.cs:line 6

But, you can use ExceptionDispatchInfo to capture and re-throw the exception, like this:

using System;

class Program {
    static void Main(string[] args) {
        try {
            Test();
        }
        catch (Exception ex) {
            Console.WriteLine(ex.ToString());
        }
        Console.ReadLine();
    }
    static void Test() {
        try {
            throw new ArgumentException();              // Line 15
        }
        catch(Exception ex) {
            ExceptionDispatchInfo.Capture(ex).Throw();  // Line 18
        }
    }
}

Then it will output this:

System.ArgumentException: Value does not fall within the expected range.
   at Program.Test() in Program.cs:line 15
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Program.Test() in Program.cs:line 18
   at Program.Main(String[] args) in Program.cs:line 6

As you can see, ExceptionDispatchInfo.Throw appends additional information to the stack trace of the original exception, adding the fact that it was re-thrown, but it retains the original line number and exception type. See the MSDN documentation for more information.