C# - Register a third party COM DLL during a pre-build event

Question

I have a dependency on several COM components. My project is managed. I want to ensure that the most recent version of the COM DLL is registered pre-build. I have added regsvr32 calls on the DLLs in the pre-build step but it never seems to work correctly. When the project is built it complains that the type isn't registered. I have both isolated and non-isolated components.

How do people handle this situation? Is regsvr32 the only answer? Why does MSBuild fail to notice that the types have been registered?

Answer 1

Regsvr32 is the way to register your typelib and COM server information in the registry. It's a trivial process, and I'm suprised that it doesn't work. Have you hand verified the process to make sure its not something else, like supplying the wrong path to regsvr32?

Answer 2

I solved this problem by calling a batch script:

$(ProjectDir)register.bat "$(SolutionDir)"

Batch:

regsvr32 "%~1ThirdParty\comdll1.dll" /s
if %ERRORLEVEL% NEQ 0 GOTO Exit
regsvr32 "%~1ThirdParty\comdll2.dll" /s
if %ERRORLEVEL% NEQ 0 GOTO Exit
regsvr32 "%~1ThirdParty\comdll3.dll" /s
EXIT:

The issue is that Visual Studio can only check the ERRORLEVEL value once, at the end. If comdll2 failed to register but comdll3 succeeded then the ERRORLEVEL would be 0 and the build would not fail.