Repetivie Try/Catch Blocks

[Steve Murphy]

I have a couple of standard Try/Catch blocks that I use repeatedly. Is there
anyway to wrap these blocks into a method call? Or does C# have anything like a
C++ macro?

Thanks,
Steve Murphy

[Nicholas Paldino [.NET/C# MVP]]

Steve,

Unfortunately, no, there isn't anything like a macro.

In VS.NET 2005 though, you can have code snippets, meaning that when you
type a certain phrase, you can have it extend into a larger block of code.

Check out the section on MSDN titled "Investigating Code Snippet
Technology", located at (watch for line wrap):

http://msdn.microsoft.com/library/de...desnippets.asp

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com
"Steve Murphy" <sm*****@granite-ridge.com> wrote in message
news:%2****************@TK2MSFTNGP12.phx.gbl...

I have a couple of standard Try/Catch blocks that I use repeatedly. Is
there
anyway to wrap these blocks into a method call? Or does C# have anything
like a
C++ macro?

Thanks,
Steve Murphy

[Paul E Collins]

"Steve Murphy" <sm*****@granite-ridge.com> wrote:

I have a couple of standard Try/Catch blocks that I
use repeatedly. Is there anyway to wrap these blocks
into a method call?

Here is one possibility, using a delegate (which you could modify to
return a value). Personally, I wouldn't use this approach - it seems a
bit clumsy and long-winded - but I can't think of an alternative.

private delegate void GenericDelegate();

static void Main(string[] args)
{
RunWithHandler(new GenericDelegate(DoDivision));
}

private static void DoDivision()
{
int i = 0;
Console.WriteLine(i / i); // this will fail
}

private static void RunWithHandler(GenericDelegate theCode)
{
try
{
theCode();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}

P.

[clu]

Oh ... the missing macros !

Take a look at this post and to its comments:
http://blogs.msdn.com/ericgu/archive...31/363861.aspx

Claudio

[Steve McLellan]

"clu" <cl************@gmail.com> wrote in message
news:11**********************@o13g2000cwo.googlegr oups.com...

Oh ... the missing macros !

Take a look at this post and to its comments:
http://blogs.msdn.com/ericgu/archive...31/363861.aspx

I'd agree with the author... you can get into a right old mess with macros
in c++...

[Helge Jensen]

Steve Murphy wrote:

I have a couple of standard Try/Catch blocks that I use repeatedly. Is there
anyway to wrap these blocks into a method call? Or does C# have anything like a
C++ macro?

As suggested by others, you can use delegates combined with functions,
but that has the disadvangate of Exception wrapping:
delegate-invocations doesn't directly throw exceptions, but throws an
exception with the original exception as it's .Inner. This is
understandable with async execution of delegates but I cannot find any
reason for the behaciour with sync. invoked delegates.

Also the delegate-approach requires a delegate for every signarure of
the code to exec, making for almost as big a mess as copying try...catch.

You could consider whether your prorgam could be implemented with less
catch-clauses. I usually advice to catch only when one of:

- You can fix the situation: try another way, ...
- You are at the top of the stack

A special exception from this is catch for logging:

try {
...
} catch ( Exception e ) {
Logging.Log(e);
throw;
}

If you find that the catch-logic is actually "finally" logic, and there
is a 1-1 relation between the code to exec and the error, you can use
the "using" pattern for cleanup.

Finally, if all else fail, you can try to factorize the body of the
catch-handler into a function so you wont have to copy all the
exception-handling code into every catch-block.

--
Helge