Getting the PID of foreground window

Question

I'm writing an app that does actions depending on the current context. My goal is to get the path for the EXE that's currently running in the foreground. For this to work, I need to get the process handle for the foreground window. The problem is, with GetForegroundWindow() I get back a window handle, and for OpenProcess() to work I need to pass in a process ID, not a window handle. Any suggestions?

The code I'm currently using:

SetPrivilege(); //setting SE_DEBUG_NAME privilige for getting process path
DWORD processId = GetProcessId(GetForegroundWindow());
std::cout << "PID: " << processId << '\n'; //for debug
std::string ret;
HANDLE handle = OpenProcess(
    PROCESS_QUERY_LIMITED_INFORMATION,
    FALSE,
    processId
);

Are you ignoring [UI Automation](https://learn.microsoft.com/en-us/windows/win32/winauto/entry-uiauto-win32) out of intent or ignorance? — IInspectable, May 16 '21 at 23:16
The first reply solved it for me, was a simple fix, don't know how I didn't think of that. And to answer IInspectable 's question, out of intent. — Zágoni Mátyás, May 19 '21 at 15:27

score 2 · Accepted Answer · answered May 16 '21 at 20:41

2

You can use GetWindowThreadProcessId:

HWND hWnd = GetForegroundWindow ();
DWORD process_id;
GetWindowThreadProcessId (hWnd, &process_id);

It's not immediately obvious how this function reports error conditions.

answered May 16 '21 at 20:41

Paul Sanders

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The documentation doesnt say, but the only possible way it can report an error is by returning 0 for the thread ID, which your example is ignoring – Remy Lebeau May 16 '21 at 21:58
@RemyLebeau That would seem reasonable, yes. – Paul Sanders May 16 '21 at 22:15

Getting the PID of foreground window

1 Answers1