Visual Basic® 2010 Unleashed

Handling Exceptions

Functions from Windows API generally return a numeric value as their result (called HRESULT), for communicating with the caller if the function succeeded or failed. Prior to .NET 2.0, getting information on functions failures was a difficult task. Starting from .NET 2.0 you can handle exceptions coming from the P/Invokes world with a classic Try..Catch block. The real improvement is that the .NET Framework can wrap unmanaged errors that have a .NET counterpart into managed exceptions. For example, if a Windows API invocation causes an out-of-memory error, the .NET Framework maps such error as an OutOfMemoryException that you can embrace within a normal Try..Catch block. By the way, it is reasonable that not all unmanaged errors ...