Was looking at this Fx-Cop rule: http://msdn.microsoft.com/en-us/library/ms182363(v=vs.80).aspx
When you need to bubble up the exception there are few ways you can do it.
Consider a Method Foo throws some exception.
private static void Foo()
{
//
// Some nasty behavior.
//
throw new Exception();
}
I. Throw with parameter
private static void ThrowWithVariable()
{
try
{
Foo();
}
catch (Exception ex)
{
//do something and bubble up
throw ex;
}
}
Output:
Message: Exception of type 'System.Exception' was thrown.
StackTrace: at ConsoleApplicationThrow.Ex.ThrowWithVariable() in H:\Study\ConsoleApplicationThrow\ConsoleApplicationThrow\Program.cs:line 102
at ConsoleApplicationThrow.Ex.Main() in H:\Study\ConsoleApplicationThrow\ConsoleApplicationThrow\Program.cs:line 20
II. Throw without parameter
private static void ThrowWithoutVariable()
{
try
{
Foo();
}
catch
{
//do something and bubble up
throw;
}
}
Output:
Message: Exception of type 'System.Exception' was thrown.
StackTrace: at ConsoleApplicationThrow.Ex.Foo() in H:\\Study\ConsoleApplicationThrow\ConsoleApplicationThrow\Program.cs:line 67
at ConsoleApplicationThrow.Ex.ThrowWithoutVariable() in H:\ Study\ConsoleApplicationThrow\ConsoleApplicationThrow\Program.cs:line 90
at ConsoleApplicationThrow.Ex.Main() in H:\ Study\ConsoleApplicationThrow\ConsoleApplicationThrow\Program.cs:line 35
III. Throw after wrapping in new exception
private static void ThrowWithNewException()
{
try
{
Foo();
}
catch (Exception ex)
{
//do something and bubble up
throw new Exception("Some useful info", ex);
}
}
Output:
Message: Some useful info
StackTrace: at ConsoleApplicationThrow.Ex.ThrowWithNewException() in H:\Study\ConsoleApplicationThrow\ConsoleApplicationThrow\Program.cs:line 78
at ConsoleApplicationThrow.Ex.Main() in H:\Study\ConsoleApplicationThrow\ConsoleApplicationThrow\Program.cs:line 50
Conclusions:
1. When the exceptions are needed to be bubbled up use “throw without parameter” instead of “throw with parameter”. This will ensure you will not lose out on actual line of code throwing exception.
2. Exception to this is when you would be adding some extra information and would be throwing new exception.
Few other related links:
