.NET Exception Handling Guidelines: Catching Exceptions (part 4)

• Unless you are writing framework code, do not consume non-specific errors by catching System.Exception or System.SystemException.
• There are occasional circumstances when swallowing errors in applications are justified, but these are few and far between.
• Do NOT over catch. Over-catching can hide bugs. Let exceptions propagate up the call stack.
• Catch specific exceptions only when you know you can recover from them. Do NOT catch exceptions you can do nothing about.
• If you can avoid throwing an exception, by using a TryParse, Exists or some other method, do so.
• Use try-finally rather than try-catch for cleanup code.
• For objects that implement IDisposable consider the using statement:

• Try to avoid catching and rethrowing: it can decrease the effectiveness of debugging.
• If you do catch and rethrow an exception, use an empty throw rather than throw ex, otherwise you will lose the original exception’s call stack:

• In web applications, create a global unhandled error handler that logs everything. There are several tools available to assist with this:
  SmartAssembly
  Jeff Attwood’s CodeProject article
  ELMAH

The links to the previous posts on this topic are here: part 1, part 2, part 3.