public class LdwmForm : Form

    {

        public LdwmForm()

        {

            Initialize();

        }

        /// <summary>

        /// 界面加载

        /// </summary>

        /// <param name="e"></param>

        protected override void OnLoad(EventArgs e)

        {

            dwmInitialize();

            base.OnLoad(e);

        }

        /// <summary>

        ///

        /// </summary>

        /// <param name="e"></param>

        protected override void OnMouseDown(MouseEventArgs e)

        {

            _IsMouseDown = true;

            _location = this.Location;

            _startPoint = Control.MousePosition;

            base.OnMouseDown(e);

        }

        /// <summary>

        ///

        /// </summary>

        /// <param name="e"></param>

        protected override void OnMouseMove(MouseEventArgs e)

        {

            if (_IsMouseDown)

            {

                Point p = Control.MousePosition;

                this.Location = new Point(_location.X + p.X - _startPoint.X, _location.Y + p.Y - _startPoint.Y);

            }

            base.OnMouseMove(e);

        }

        /// <summary>

        ///

        /// </summary>

        /// <param name="e"></param>

        protected override void OnMouseUp(MouseEventArgs e)

        {

            _IsMouseDown = false;

            base.OnMouseUp(e);

        }

        /// <summary>

        /// 界面绘制

        /// </summary>

        /// <param name="e"></param>

        protected override void OnPaint(PaintEventArgs e)

        {

            base.OnPaint(e);

            e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;

            if (dwmEnabled)

            {

                e.Graphics.Clear(Color.FromArgb(, , , ));

                DrawShadow(this.Size, dwmleft, e.Graphics);

            }

            RectangleF rect = new RectangleF(dwmleft - 0.5f, dwmtop - 0.5f, this.Width - dwmleft - dwmright + 0.5f, this.Height - dwmtop - dwmbottom + 0.5f);

            SolidBrush brush = new SolidBrush(this.BackColor);

            e.Graphics.FillRectangle(brush, rect);

            brush.Dispose(); brush = null;

        }

        /// <summary>

        ///

        /// </summary>

        protected override CreateParams CreateParams

        {

            get

            {

                CreateParams cp = base.CreateParams;

                cp.Style = cp.Style | WS_MINIMIZEBOX;

                return cp;

            }

        }

        /// <summary>

        /// 绘制阴影效果

        /// </summary>

        /// <param name="size">控件尺寸</param>

        /// <param name="radius">阴影半径</param>

        /// <param name="g">绘图区</param>

        private void DrawShadow(Size size, int radius, Graphics g)

        {

            if (radius <= ) return;

            int d =  * radius;

            #region[LinearGradientBrush]

            ColorBlend blend = new ColorBlend();

            blend.Colors = new Color[] { Color.FromArgb(, Color.Black), Color.FromArgb(, Color.Black), Color.FromArgb(, Color.Black) };

            blend.Positions = new float[] { , 0.4f,  };

            LinearGradientBrush brushleft = new LinearGradientBrush(new Point(radius, ), new Point(, ), Color.FromArgb(, Color.Black), Color.FromArgb(, Color.Black));

            brushleft.InterpolationColors = blend;

            LinearGradientBrush brushright = new LinearGradientBrush(new Point(size.Width - radius - , ), new Point(size.Width, ), Color.FromArgb(, Color.Black), Color.FromArgb(, Color.Black));

            brushright.InterpolationColors = blend;

            LinearGradientBrush brushtop = new LinearGradientBrush(new Point(, radius), new Point(, ), Color.FromArgb(, Color.Black), Color.FromArgb(, Color.Black));

            brushtop.InterpolationColors = blend;

            LinearGradientBrush brushbottom = new LinearGradientBrush(new Point(, size.Height - radius - ), new Point(, size.Height), Color.FromArgb(, Color.Black), Color.FromArgb(, Color.Black));

            brushbottom.InterpolationColors = blend;

            #endregion

            #region[path]

            GraphicsPath pathlefttop = new GraphicsPath();

            pathlefttop.AddPie(new Rectangle(, , d, d), , );

            GraphicsPath pathrighttop = new GraphicsPath();

            pathrighttop.AddPie(new Rectangle(this.Width - d, , d, d), , );

            GraphicsPath pathleftbottom = new GraphicsPath();

            pathleftbottom.AddPie(new Rectangle(, this.Height - d, d, d), , );

            GraphicsPath pathrightbottom = new GraphicsPath();

            pathrightbottom.AddPie(new Rectangle(this.Width - d, this.Height - d, d, d), , );

            #endregion

            #region[PathGradientBrush]

            PathGradientBrush brushlefttop = new PathGradientBrush(pathlefttop);

            brushlefttop.CenterPoint = new Point(radius, radius);

            brushlefttop.CenterColor = Color.FromArgb(, Color.Black);

            brushlefttop.SurroundColors = new Color[] { Color.FromArgb(, Color.Black) };

            //brushlefttop.InterpolationColors = blend;

            PathGradientBrush brushrighttop = new PathGradientBrush(pathrighttop);

            brushrighttop.CenterPoint = new Point(this.Width - radius, radius);

            brushrighttop.CenterColor = Color.FromArgb(, Color.Black);

            brushrighttop.SurroundColors = new Color[] { Color.FromArgb(, Color.Black) };

            //brushrighttop.InterpolationColors = blend;

            PathGradientBrush brushleftbottom = new PathGradientBrush(pathleftbottom);

            brushleftbottom.CenterPoint = new Point(radius, this.Height - radius);

            brushleftbottom.CenterColor = Color.FromArgb(, Color.Black);

            brushleftbottom.SurroundColors = new Color[] { Color.FromArgb(, Color.Black) };

            //brushleftbottom.InterpolationColors = blend;

            PathGradientBrush brushrightbottom = new PathGradientBrush(pathrightbottom);

            brushrightbottom.CenterPoint = new Point(this.Width - radius, this.Height - radius);

            brushrightbottom.CenterColor = Color.FromArgb(, Color.Black);

            brushrightbottom.SurroundColors = new Color[] { Color.FromArgb(, Color.Black) };

            //brushrightbottom.InterpolationColors = blend;

            #endregion

            #region[draw]

            g.FillRectangle(brushleft, new RectangleF(, radius - 0.5f, radius, this.Height - d + 0.5f));

            g.FillRectangle(brushright, new RectangleF(this.Width - radius - , radius - 0.5f, radius, this.Height - d + 0.5f));

            g.FillRectangle(brushtop, new RectangleF(radius - 0.5f, , this.Width - d + 0.5f, radius));

            g.FillRectangle(brushbottom, new RectangleF(radius - 0.5f, this.Height - radius - , this.Width - d + 0.5f, radius));

            g.FillPath(brushlefttop, pathlefttop);

            g.FillPath(brushrighttop, pathrighttop);

            g.FillPath(brushleftbottom, pathleftbottom);

            g.FillPath(brushrightbottom, pathrightbottom);

            #endregion

            #region[dispose]

            brushleft.Dispose(); brushleft = null;

            brushright.Dispose(); brushright = null;

            brushtop.Dispose(); brushtop = null;

            brushbottom.Dispose(); brushbottom = null;

            pathlefttop.Dispose(); pathlefttop = null;

            pathrighttop.Dispose(); pathrighttop = null;

            pathleftbottom.Dispose(); pathleftbottom = null;

            pathrightbottom.Dispose(); pathrightbottom = null;

            brushlefttop.Dispose(); brushlefttop = null;

            brushrighttop.Dispose(); brushrighttop = null;

            brushleftbottom.Dispose(); brushleftbottom = null;

            brushrightbottom.Dispose(); brushrightbottom = null;

            #endregion

        }

        /// <summary>

        /// 初始化

        /// </summary>

        private void Initialize()

        {

            this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.OptimizedDoubleBuffer, true);

            this.FormBorderStyle = FormBorderStyle.None;

            this.StartPosition = FormStartPosition.CenterScreen;

            dwmleft = ;

            dwmtop = ;

            dwmright = ;

            dwmbottom = ;

        }

        /// <summary>

        /// dwm初始化

        /// </summary>

        private void dwmInitialize()

        {

            #region[dwmInitialize]

            this.dwmEnabled = true;

            int flag = ;

            MARGINS mg = new MARGINS();

            mg.m_Left = dwmleft;

            mg.m_Top = dwmtop;

            mg.m_Right = dwmright;

            mg.m_Bottom = dwmbottom;

            //判断Vista系统

            if (System.Environment.OSVersion.Version.Major >= )

            {

                DwmIsCompositionEnabled(ref flag);    //检测Aero是否为打开

                if (flag > )

                {

                    DwmExtendFrameIntoClientArea(this.Handle, ref mg);

                }

                else

                {

                    dwmEnabled = false;

                    dwmleft = ;

                    dwmtop = ;

                    dwmright = ;

                    dwmbottom = ;

                    //MessageBox.Show("Desktop Composition is Disabled!");

                }

            }

            else

            {

                dwmEnabled = false;

                dwmleft = ;

                dwmtop = ;

                dwmright = ;

                dwmbottom = ;

                //MessageBox.Show("Please run this on Windows Vista.");

            }

            GC.Collect();

            #endregion

        }

        protected bool dwmEnabled;

        protected int dwmleft;

        protected int dwmtop;

        protected int dwmright;

        protected int dwmbottom;

        private bool _IsMouseDown;

        private Point _location;

        private Point _startPoint;

        private const int WS_MINIMIZEBOX = 0x00020000;

        /// <summary>

        ///

        /// </summary>

        public struct MARGINS

        {

            public int m_Left;

            public int m_Right;

            public int m_Top;

            public int m_Bottom;

        };

        [DllImport("dwmapi.dll")]

        private static extern void DwmIsCompositionEnabled(ref int enabledptr);

        [DllImport("dwmapi.dll", PreserveSig = false)]

        public static extern bool DwmIsCompositionEnabled();

        [DllImport("dwmapi.dll")]

        private static extern void DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS margin);

    }

public partial class Form1 : LdwmForm

    {

        public Form1()

        {

            InitializeComponent();

            dwmleft = ;//这个是调节窗体阴影宽度，设置一个很大的值，可以使整个窗体全透

            dwmtop = ;

            dwmright = ;

            dwmbottom = ;

        }

        protected override void OnPaint(PaintEventArgs e)

        {

            base.OnPaint(e);

            e.Graphics.FillRectangle(new SolidBrush(Color.FromArgb(, , , )), this.ClientRectangle);//这里实现窗体半透明

        }

    }