GetWindowThreadProcessId function (winuser.h)

Retrieves the identifier of the thread that created the specified window and, optionally, the identifier of the process that created the window.

Syntax

DWORD GetWindowThreadProcessId(
  [in]            HWND    hWnd,
  [out, optional] LPDWORD lpdwProcessId
);

Parameters

[in] hWnd

Type: HWND

A handle to the window.

[out, optional] lpdwProcessId

Type: LPDWORD

A pointer to a variable that receives the process identifier. If this parameter is not NULL, GetWindowThreadProcessId copies the identifier of the process to the variable; otherwise, it does not.

Return value

Type: DWORD

The return value is the identifier of the thread that created the window.

Requirements

   
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header winuser.h (include Windows.h)
Library User32.lib
DLL User32.dll
API set ext-ms-win-ntuser-window-l1-1-0 (introduced in Windows 8)

See also

Windows Overview