1.设置窗体opacity属性：
2.窗体的BackColor和TransparencyKey属性设置相同的值：
2.加using System.Runtime.InteropServices;引用然后加上以下代码：
[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();protected override void OnLoad(EventArgs e){if (DwmIsCompositionEnabled()){MARGINS m = new MARGINS();m.Right = m.Left = m.Top = this.Width + this.Height;DwmExtendFrameIntoClientArea(this.Handle, ref m);}base.OnLoad(e);}protected override void OnPaintBackground(PaintEventArgs e){base.OnPaintBackground(e);if (DwmIsCompositionEnabled()){e.Graphics.Clear(Color.Black);}}
待续...
