Win32 what is hwnd

This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. GetWindow function winuser. The function examines only child windows of the specified window.

It does not examine descendant windows. For more information, see Owned Windows. Requirements Minimum supported client Windows Professional [desktop apps only] Minimum supported server Windows Server [desktop apps only] Target Platform Windows Header winuser. The answer is GetDlgItem. We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts learning and sharing knowledge.

This is just example code, and not my real code, it's used in a diffrent way in my program. Hope to hear from you! Thanks, Schoorsteen. Thanks in advance! If window creation failed, it returned NULL. We then show the window by calling ShowWindow.

The first argument for this function is the handle to the window. The second argument is the show style, which indicates how the window is to be displayed. Most applications just pass the cmdshow argument passed in WinMain. After the window is shown, it must be updated by a call to UpdateWindow. It causes an update message to be sent to the window. We will learn what this means in another tutorial. Now comes the heart of the application: The message pump.

It pumps messages sent to this application by the operating system, and dispatches the messages to the window procedure. The GetMessage call returns non-zero until the application receieves a messages that causes it to quit, in which case it returns 0. The only argument that concerns us is the pointer to an MSG structure that will be filled in with information about the message. The other arguments are all 0. Inside the message loop, TranslateMessage translates virtual-key messages into character messages.

The meaning of this, again, is unimportant to us. It takes a pointer to an MSG structure. The call directly following it, DispatchMessage , dispatches the message pointed to by its argument to the window's window procedure.

The last thing WinMain must do is return a status code. The wParam member of the MSG structure contains this return value, so it is returned.

See here for more information on system wide hooks. If the window procedure for the window in question is under your control or if you can subclass it , then I would suggest registering a custom message that the window responds to with a non-zero result.

Sending that message to any other window or an invalid HWND will result in 0. Of course, that only tells you if the HWND refers to one of the windows that you control -- but perhaps given other answers above that might even be advantageous.

Asked By: Doug Ferguson. Answered By: Brian R.