How do you handle exceptions between .NET and COM?

Q

Managed Code and Unmanaged Code related ASP.NET - How do you handle exceptions between .NET and COM?

✍: Guest

A

.NET handles errors through exception classes. COM handles errors through 32-bit data types called HRESULTs. All of the .NET exception classes include HResult properties that map to COM HRESULT codes.

If an exception occurs in a .NET object, the exception is automatically mapped to the appropriate HRESULT and returned to COM. Similarly, if an exception occurs in a COM object, the COM HRESULT is mapped to the appropriate exception class, which is returned to .NET, where it can be handled just like any other exception.

If you are creating your own .NET exception classes for use with COM, be sure to set the class’s HResult property so that the exception can be handled within COM.

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