Can I call a Win32 API from the Visual Studio Immediate Window?

Question

I'm debugging a C++ Win32 application and I'd like to call an arbitrary Win32 API from the context of that process, as though the program had run this line of code:

DestroyWindow(0x00021c0e);

But entering that into the Immediate Window gives:

CXX0017: Error: symbol "DestroyWindow" not found

Edit: Using the full name of the function, {,,user32.dll}_NtUserDestroyWindow@4, I can get the Immediate Window to understand which function I mean and display the function's address:

{,,user32.dll}_NtUserDestroyWindow@4
0x76600454 _NtUserDestroyWindow@4

but when I try to call it, this happens:

{,,user32.dll}_NtUserDestroyWindow@4(0x00021c0e);
CXX0004: Error: syntax error

Is it even possible to call a C function from the Immediate Window like this, or am I barking up the wrong tree?

Answer 1

Once you have the function address (as you've done in the updated question), you can try casting it to a function pointer and calling it:

(*(BOOL (*)(HWND))0x76600454)((HWND)0x00021c0e)

The first part of that casts the address to BOOL (*)(HWND), which is a pointer to a function taking an HWND parameter and returning BOOL. Then, the function pointer is dereferenced and called. Make sure to get the parameters correct, otherwise bad things will happen. On 64-bit systems, and HWND might be 64 bits, so you might not be able to get away with passing the parameter as an int.

Edit: See the comments for the full story.