Win32: How to Hide 3Rd Party Windows in Taskbar by Hwnd

Win32: How to hide 3rd party windows in taskbar by hWnd

Before you use SetWindowLong, call ShowWindow(hWnd, SW_HIDE), then call SetWindowLong, then call ShowWindow again like ShowWindow(hWnd, SW_SHOW). So your code will look like this:

long style= GetWindowLong(hWnd, GWL_STYLE);
style &= ~(WS_VISIBLE);    // this works - window become invisible 

style |= WS_EX_TOOLWINDOW;   // flags don't work - windows remains in taskbar
style &= ~(WS_EX_APPWINDOW); 

ShowWindow(hWnd, SW_HIDE); // hide the window
SetWindowLong(hWnd, GWL_STYLE, style); // set the style
ShowWindow(hWnd, SW_SHOW); // show the window for the new style to come into effect
ShowWindow(hWnd, SW_HIDE); // hide the window so we can't see it

Here is a relevant quote from Microsoft's Website:

To prevent the window button from being placed on the taskbar, create
the unowned window with the WS_EX_TOOLWINDOW extended style. As an
alternative, you can create a hidden window and make this hidden
window the owner of your visible window.

The Shell will remove a window's button from the taskbar only if the
window's style supports visible taskbar buttons. If you want to
dynamically change a window's style to one that doesn't support
visible taskbar buttons, you must hide the window first (by calling
ShowWindow with SW_HIDE), change the window style, and then show the
window.

c# remove 3rd party application from taskbar

If you have the handle to the window you can call ShowWindow() through the Win32 API. Then you can do:

// Let the window disappear (even from taskbar)
ShowWindow(this.Handle, WindowShowStyle.Hide);

// Revive the window back to the user
ShowWindow(this.Handle, WindowShowStyle.ShowNoActivate);

So from now, all your problem is to get the handle of the window you like to hide:

Process[] procs = Process.GetProcesses();
IntPtr hWnd;
foreach(Process proc in procs)
{
   if ((hWnd = proc.MainWindowHandle) != IntPtr.Zero)
   {
      Console.WriteLine("{0} : {1}", proc.ProcessName, hWnd);
   }
}

C++ don't display in the taskbar a window created with CreateWindow

set 'dwStyle' to WS_POPUP, the third argument:

HWND WINAPI CreateWindow(
    __in_opt  LPCTSTR lpClassName,
    __in_opt  LPCTSTR lpWindowName,
    __in      DWORD dwStyle,
    __in      int x,
    __in      int y,
    __in      int nWidth,
    __in      int nHeight,
    __in_opt  HWND hWndParent,
    __in_opt  HMENU hMenu,
    __in_opt  HINSTANCE hInstance,
    __in_opt  LPVOID lpParam);

If you're doing win32, I suggest, for your own sanity, you give Qt a try.

Why does WM_CLOSE/DESTROY only partially close my Notepad window?

I'm using [CloseWindow] to try to close the window.

CloseWindow doesn't close a window -- it minimizes it.

Instead, send the window a WM_CLOSE message:

SendMessage(h, WM_CLOSE, 0, 0);

Why does the task bar appear when I display a self-drawn modeless dialog? .. sometimes?

Following a long discussion I come to the conclusion that DestroyWindow was not the problem. I found in the end that displaying a dialog.. clicking on the POS, then clicking back on the dialog that sometimes the taskbar would appear. I have spent an entire week trying to find reasons for all of this but to no avail. I thought that assigning the POS window as the owner would solve the problem - it didn't. In the end the solution for my problem was to determine if the taskbar is obscured completely before showing my dialog. If it is, I hide the taskbar for the duration which my dialog is displayed (set its placement to SW_HIDE) and then set it to SW_SHOW when I close my dialog. The task bar doesn't pop up and annoy people anymore. Not a fantastic solution for other peoples' applications perhaps, but perfect for our customers.

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