Get Window Handle of calling app in a DLL function

[Worm]

I'm writing a DLL and would like to be able to obtain the handle of the calling applications window programmatically rather than passing it as a parameter. All the things I've tried seem to fail.

Any ideas?

[Fluid Byte]

GetForegroundWindow_()

[Worm]

Thanks. I should know by now to be as specific as possible.

The solution you provided would work as long as the window is the active window. The problem comes if the app doesn't have focus and the function is called, it would give me the wrong handle. The DLL function will more than likely be called within a timer event, so there is a real chance the window will *not* be the active window.

[Trond]

What if the application doesn't even have a window?

[Worm]

Good point, but in this case I know there will always be a window.

[Trond]

But Windows doesn't know every process has a window, so it doesn't have a function to get the window from the process. Why don't you just pass the window handle (from which you can get the process, since every window has a process)?

[Worm]

Passing the handle is an option, but if I can obtain the handle through code I'd rather do that.

[srod]

The only other option which comes to mind is using something like EnumThreadWindows_(), but then you'll proably need to check the window title etc.

[netmaestro]

It seems like there should be an easier way, but this will work:

Code: Select all

Procedure ListWindows(hwnd, param)
  Shared CallerWindow
  GetWindowThreadProcessId_(hwnd, @processid)
  If GetCurrentProcessId_() = processid
    CallerWindow = hwnd
    ProcedureReturn #False
  Else
    ProcedureReturn #True
  EndIf
EndProcedure

ProcedureDLL GetCallerhWnd()
  Shared CallerWindow
  EnumWindows_(@ListWindows(), 0)
  ProcedureReturn CallerWindow
EndProcedure

[dell_jockey]

Passing the handle is an option, but if I can obtain the handle through code I'd rather do that.

passing a handle IS code too. Put it in the DLL attach procedure and you're good to go.

[Worm]

I agree, but the concept was to not need to worry about that and simply let the DLL get the handle. Netmaestro's code seems to work perfectly when I use it in PB, but if I try it in a DLL, I do not get the handle I need.

So, the answer for me in this instance is to make the handle a parameter that gets passed in.

Thanks to all.

[Kale]

Passing the handle is an option, but if I can obtain the handle through code I'd rather do that.

passing a handle IS code too. Put it in the DLL attach procedure and you're good to go.

Yeah. As wierd and long winded as it may seem netmaestro's code is actually the right way to get the handle, but it's far more simpler to just pass the handle to the dll.