代码

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms;using System.Reflection;using System.Runtime.InteropServices;//引用DLL申明namespace WindowsFormsApplication1{    public partial class Form1 : Form    {        //DLL申明        [StructLayout(LayoutKind.Sequential)]        public struct MARGINS        {            public int Left;            public int Right;            public int Top;            public int Bottom;        }        //DLL申明        [DllImport("dwmapi.dll", PreserveSig = false)]        static extern void DwmExtendFrameIntoClientArea(IntPtr hwnd, ref MARGINS        margins);        //DLL申明        [DllImport("dwmapi.dll", PreserveSig = false)]        static extern bool DwmIsCompositionEnabled();        //直接添加代码        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);        }        //直接添加代码        protected override void OnPaintBackground(PaintEventArgs e)        {            base.OnPaintBackground(e);            if (DwmIsCompositionEnabled())            {                e.Graphics.Clear(Color.Black);            }        }        public Form1()        {            InitializeComponent();        }    }}

这中效果的实现主要是调用了系统的dwmapi.dll。

dwmapi.dll是Microsoft Desktop Window Manager API（桌面窗口管理器DWM 的公用界面）的动态链接库，正常文件，主要用作桌面效果的api。

DWM 是一种新界面，在除 Windows Vista Home Basic 之外的所有 Windows Vista 版本中均提供 DWM 界面。所以这种效果只能在Vista之后的系统中使用。