Can you catch a native exception in C# code?

Question

In C# code can you catch a native exception thrown from deep in some unmanaged library? If so do you need to do anything differently to catch it or does a standard try...catch get it?

Answer 1

You can use Win32Exception and use its NativeErrorCode property to handle it appropriately.

// http://support.microsoft.com/kb/186550 const int ERROR_FILE_NOT_FOUND = 2; const int ERROR_ACCESS_DENIED = 5; const int ERROR_NO_APP_ASSOCIATED = 1155;   void OpenFile(string filePath) {     Process process = new Process();      try     {         // Calls native application registered for the file type         // This may throw native exception         process.StartInfo.FileName = filePath;         process.StartInfo.Verb = "Open";         process.StartInfo.CreateNoWindow = true;         process.Start();     }     catch (Win32Exception e)     {         if (e.NativeErrorCode == ERROR_FILE_NOT_FOUND ||              e.NativeErrorCode == ERROR_ACCESS_DENIED ||             e.NativeErrorCode == ERROR_NO_APP_ASSOCIATED)         {             MessageBox.Show(this, e.Message, "Error",                      MessageBoxButtons.OK,                      MessageBoxIcon.Exclamation);         }     } } 

Answer 2

Catch without () will catch non-CLS compliant exceptions including native exceptions.

try {  } catch {  } 

See the following FxCop rule for more info http://msdn.microsoft.com/en-gb/bb264489.aspx