从第三方DLL捕获StandardOutput

Question

I have a DLL that I call from my program which outputs status to the Visual Studio Output Window (assuming this is standard output) and I want to capture that output at run time.

All of the examples of how to do this assume I am using Process to launch an external app or console app and then capture the StandardOutput from the Process instance, which I have done more than a few times myself. But in this case my program calls the DLL directly -- I'm not starting an extra process.

While my program is calling the DLL, I want to read what it prints to standard output to log it for debugging and possibly exit my program if the DLL is failing. When the DLL call returns, my program should continue normally.

I know I need another thread to process the DLL output while my other thread is in the DLL call; I just don't know how to capture the output in the first place.

Answer 1

Your program could call Console.SetOut to replace the standard output stream with your own implementation.

This should allow you to trap standard output as needed. Note that you may also need to replace the standard error stream, depending on how the DLL is writing the output.