Hiding/Showing the Windows TaskBar

I was writing an application which had a requirement saying that the Windows taskbar needs to be hidden. While looking out for source code, I came across SystemParametersInfo() API in MSDN, which retrieves the size of the work area on the primary display monitor. The work area is the portion of the screen not obscured by the system taskbar or by application desktop toolbars.

Now, my only requirement was to retrieve the handle to the TaskBar window. I used CWnd’s FindWindow() function to do this. FindWindow() takes two parameters, the window’s class name (a WNDCLASS structure) and the windw name (the windows title). You may retrieve these properties of the window using the SPY++’s FindWindow utility that comes with Visual Studio.

Using these two functions I came up with the following code which you can use to either show or hide the taskbar and utilize the full desktop.

void gShowHideTaskBar(BOOL bHide /*=FALSE*/)
{
 CRect rectWorkArea = CRect(0,0,0,0);
 CRect rectTaskBar = CRect(0,0,0,0);
 CWnd* pWnd = CWnd::FindWindow(“Shell_TrayWnd”, “”);
 if( bHide )
 {
  // Code to Hide the System Task Bar
  SystemParametersInfo(SPI_GETWORKAREA,
                       0,
                       LPVOID)&rectWorkArea,
                       0);
  if( pWnd )
  {
   pWnd->GetWindowRect(rectTaskBar);
   rectWorkArea.bottom += rectTaskBar.Height();
   SystemParametersInfo(SPI_SETWORKAREA,
                        0,
                        LPVOID)&rectWorkArea,
                        0);
   pWnd->ShowWindow(SW_HIDE);
  }
 }
 else
 {
  // Code to Show the System Task Bar
  SystemParametersInfo(SPI_GETWORKAREA,
                       0,
                       (LPVOID)&rectWorkArea,
                       0);
  if( pWnd )
  {
   pWnd->GetWindowRect(rectTaskBar);
   rectWorkArea.bottom -= rectTaskBar.Height();
   SystemParametersInfo(SPI_SETWORKAREA,
                        0,
                        (LPVOID)&rectWorkArea,
                        0);
   pWnd->ShowWindow(SW_SHOW);
  }
 }
}

Downloads

Download source – 2 Kb
Download demo project (including release build) – 28 Kb