What message do i need to listen into my window procedure to close the GUI when right-clicking into her taskbar button and clicking on X Close window?

LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{

    switch (msg)
    {
    case ???:
    {
      //...
    }
    break;
    }

Note: Im not referring to the X into the caption/title bar.

CodePudding user response：

It's the same message you get when the user presses the [X] button in the caption bar, or chooses Close from the system menu: WM_CLOSE.

The documentation contains useful information. In particular:

An application can prompt the user for confirmation, prior to destroying a window, by processing the WM_CLOSE message and calling the DestroyWindow function only if the user confirms the choice.

By default, the DefWindowProc function calls the DestroyWindow function to destroy the window.

CodePudding user response：

The first message is WM_CLOSE. If you handle that message, you have a chance to cancel closing the window.

If the WM_CLOSE handler decided to destroy the window in response (the DefWindowProc function does that), more messages are coming: WM_DESTROY, and finally WM_NCDESTROY. Unlike WM_CLOSE, it’s impossible to cancel closing the window in these handlers, too late.