Search code examples
c#interopx8664-bitregsvr32

Runtime C# knowing if 32-bit or 64-bit version of COM Interface is being used

I want to build a DLL Class Library use COM Interop, with C#, target ANY CPU, and register it as 32-bit and 64-bit interfaces.

I want to be able to, at runtime, display what interface was used - if I am using the 32-bit version, or 64-bit version.

Any ideas?

Solution

  • In order for a process to load a 32-bit DLL, the process has to be 32-bit. And same for 64-bit. So to find out what has been loaded, assuming it has already worked, you just need to find out the bit-ness of the CLR:

    if (System.IntPtr.Size == 8)
{
    // 64-bit
}
else
{
    // 32-bit
}

    PS. for discussion of whether you need to check for a size of 16, see my answer to this question.