Accessing Windows API Constants and Structs for P/Invoke

Question

Quick question: How can I access the BN_CLICKED constant and other constants defined for the Win32 API from .NET? Are they defined in some library? Do I have to define them myself? If so, where can I find these values? And are the values version-specific between versions of Windows?

Answer 1

I find the PInvoke Interop Assistant to be really helpful: http://blogs.microsoft.co.il/blogs/sasha/archive/2008/01/12/p-invoke-signature-generator.aspx.

It has almost everything and can convert the C++ to C#/VB for you. I rarely, if ever, resort to searching google/pinvoke.net anymore.

Here's the MSDN Magazine Article: http://msdn.microsoft.com/en-us/magazine/cc164193.aspx

The original January 2008 MSDN Magazine Article is now only available as a .CHM help file download, linked from the very bottom of https://msdn.microsoft.com/magazine/msdn-magazine-issues. (Column "CLR Inside Out: Marshaling between managed and unmanaged code.")

And here's the download: http://download.microsoft.com/download/f/2/7/f279e71e-efb0-4155-873d-5554a0608523/CLRInsideOut2008_01.exe. The source code can be found at http://clrinterop.codeplex.com/.

Answer 2

You could download the Microsoft Platform SDK and take a look at the header files (*.h). E.g. the BN_CLICKED is defined in the winuser.h file.

Usually, if you just need one or two constants, a Google search and a look at the first few results is also sufficient, since the value is printed there.