[StructLayout(LayoutKind.Sequential)] public struct MARGINS {   public int Left;   public int Right;   public int Top;   public int Bottom; }  [DllImport("dwmapi.dll", PreserveSig = false)] static extern void DwmExtendFrameIntoClientArea(IntPtr hwnd, ref MARGINS margins);  [DllImport("dwmapi.dll", PreserveSig = false)] static extern bool DwmIsCompositionEnabled();  public Form1() {   InitializeComponent(); }  protected override void OnLoad(EventArgs e) {   if (DwmIsCompositionEnabled())   {     MARGINS margins = new MARGINS();     margins.Right = margins.Left = margins.Top = margins.Bottom = this.Width + this.Height;     DwmExtendFrameIntoClientArea(this.Handle, ref margins);   }   base.OnLoad(e); }  protected override void OnPaintBackground(PaintEventArgs e) {   base.OnPaintBackground(e);   if (DwmIsCompositionEnabled())   {     e.Graphics.Clear(Color.Black);   } }