title: How to refresh to entire device's screen (Windows Mobile)?
body: <p>I'm working on a simple application that draws an alpha-blended picture on the screen's Device Context every 2 secs, I want to refresh the screen contents before the drawing operation (To erase the drawn pic),</p>
  
  <p>I have used many many trick but unfortunately, the screen won't refresh correctly, some regions still keep portions of the drawn pic</p>
  
  <p>I'm really frustrated from this issue :(</p>
  
  <p>These are the sources codes I have used, I'm using C#</p>
  
  <pre><code>SendMessage(HWND_BROADCAST, WM_SYSCOLORCHANGE, IntPtr.Zero, IntPtr.Zero); // wasted time in the refreshing process is enough to keep this.
  
  UpdateWindow(HWND_BROADCAST);// does not work at all!
  
  InvalidateRect(IntPtr.Zero,IntPtr.Zero,true); // the same goes here.
  
  SendMessage(HWND_BROADCAST, WM_PAINT, IntPtr.Zero, IntPtr.Zero); // pfffff !
  
  SendMessage(HWND_BROADCAST, WM_SETTINGCHANGE, new IntPtr(SPI_SETNONCLIENTMETRICS), IntPtr.Zero); // trying to refresh the explorer, no resutl
  </code></pre>
  
  <p>I used also EnumWindows and call back , very slow and does not fit my case.</p>
  
  <p>I wanna refresh the whole screen</p>
  
  <p>Help please!</p>
  
  <p>Regards</p>
  
  <p>Waleed</p>