1.无边框窗体阴影，win7(需要开启Aero效果)及以上系统
public class LdwmForm : Form { public LdwmForm() { Initialize(); } /// /// 界面加载 /// /// protected override void OnLoad(EventArgs e) { dwmInitialize(); base.OnLoad(e); } /// /// /// /// protected override void OnMouseDown(MouseEventArgs e) { _IsMouseDown = true; _location = this.Location; _startPoint = Control.MousePosition; base.OnMouseDown(e); } /// /// /// /// 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); } /// /// /// /// protected override void OnMouseUp(MouseEventArgs e) { _IsMouseDown = false; base.OnMouseUp(e); } /// /// 界面绘制 /// /// protected override void OnPaint(PaintEventArgs e) { base.OnPaint(e); e.Graphics.SmoothingMode = SmoothingMode.AntiAlias; if (dwmEnabled) { e.Graphics.Clear(Color.FromArgb(0, 0, 0, 0)); 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; } /// /// /// protected override CreateParams CreateParams { get { CreateParams cp = base.CreateParams; cp.Style = cp.Style | WS_MINIMIZEBOX; return cp; } } /// /// 绘制阴影效果 /// /// 控件尺寸 /// 阴影半径 /// 绘图区 private void DrawShadow(Size size, int radius, Graphics g) { if (radius <= 0) return; int d = 2 * radius; #region[LinearGradientBrush] ColorBlend blend = new ColorBlend(); blend.Colors = new Color[] { Color.FromArgb(100, Color.Black), Color.FromArgb(40, Color.Black), Color.FromArgb(0, Color.Black) }; blend.Positions = new float[] { 0, 0.4f, 1 }; LinearGradientBrush brushleft = new LinearGradientBrush(new Point(radius, 0), new Point(0, 0), Color.FromArgb(60, Color.Black), Color.FromArgb(0, Color.Black)); brushleft.InterpolationColors = blend; LinearGradientBrush brushright = new LinearGradientBrush(new Point(size.Width - radius - 1, 0), new Point(size.Width, 0), Color.FromArgb(80, Color.Black), Color.FromArgb(0, Color.Black)); brushright.InterpolationColors = blend; LinearGradientBrush brushtop = new LinearGradientBrush(new Point(0, radius), new Point(0, 0), Color.FromArgb(60, Color.Black), Color.FromArgb(0, Color.Black)); brushtop.InterpolationColors = blend; LinearGradientBrush brushbottom = new LinearGradientBrush(new Point(0, size.Height - radius - 1), new Point(0, size.Height), Color.FromArgb(80, Color.Black), Color.FromArgb(0, Color.Black)); brushbottom.InterpolationColors = blend; #endregion #region[path] GraphicsPath pathlefttop = new GraphicsPath(); pathlefttop.AddPie(new Rectangle(0, 0, d, d), 180, 90); GraphicsPath pathrighttop = new GraphicsPath(); pathrighttop.AddPie(new Rectangle(this.Width - d, 0, d, d), 270, 90); GraphicsPath pathleftbottom = new GraphicsPath(); pathleftbottom.AddPie(new Rectangle(0, this.Height - d, d, d), 90, 90); GraphicsPath pathrightbottom = new GraphicsPath(); pathrightbottom.AddPie(new Rectangle(this.Width - d, this.Height - d, d, d), 0, 90); #endregion #region[PathGradientBrush] PathGradientBrush brushlefttop = new PathGradientBrush(pathlefttop); brushlefttop.CenterPoint = new Point(radius, radius); brushlefttop.CenterColor = Color.FromArgb(80, Color.Black); brushlefttop.SurroundColors = new Color[] { Color.FromArgb(0, Color.Black) }; //brushlefttop.InterpolationColors = blend; PathGradientBrush brushrighttop = new PathGradientBrush(pathrighttop); brushrighttop.CenterPoint = new Point(this.Width - radius, radius); brushrighttop.CenterColor = Color.FromArgb(80, Color.Black); brushrighttop.SurroundColors = new Color[] { Color.FromArgb(0, Color.Black) }; //brushrighttop.InterpolationColors = blend; PathGradientBrush brushleftbottom = new PathGradientBrush(pathleftbottom); brushleftbottom.CenterPoint = new Point(radius, this.Height - radius); brushleftbottom.CenterColor = Color.FromArgb(80, Color.Black); brushleftbottom.SurroundColors = new Color[] { Color.FromArgb(0, Color.Black) }; //brushleftbottom.InterpolationColors = blend; PathGradientBrush brushrightbottom = new PathGradientBrush(pathrightbottom); brushrightbottom.CenterPoint = new Point(this.Width - radius, this.Height - radius); brushrightbottom.CenterColor = Color.FromArgb(80, Color.Black); brushrightbottom.SurroundColors = new Color[] { Color.FromArgb(0, Color.Black) }; //brushrightbottom.InterpolationColors = blend; #endregion #region[draw] g.FillRectangle(brushleft, new RectangleF(1, radius - 0.5f, radius, this.Height - d + 0.5f)); g.FillRectangle(brushright, new RectangleF(this.Width - radius - 1, radius - 0.5f, radius, this.Height - d + 0.5f)); g.FillRectangle(brushtop, new RectangleF(radius - 0.5f, 0, this.Width - d + 0.5f, radius)); g.FillRectangle(brushbottom, new RectangleF(radius - 0.5f, this.Height - radius - 1, 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 } /// /// 初始化 /// private void Initialize() { this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.OptimizedDoubleBuffer, true); this.FormBorderStyle = FormBorderStyle.None; this.StartPosition = FormStartPosition.CenterScreen; dwmleft = 5; dwmtop = 5; dwmright = 5; dwmbottom = 5; } /// /// dwm初始化 /// private void dwmInitialize() { #region[dwmInitialize] this.dwmEnabled = true; int flag = 0; 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 >= 6) { DwmIsCompositionEnabled(ref flag); //检测Aero是否为打开 if (flag > 0) { DwmExtendFrameIntoClientArea(this.Handle, ref mg); } else { dwmEnabled = false; dwmleft = 0; dwmtop = 0; dwmright = 0; dwmbottom = 0; //MessageBox.Show("Desktop Composition is Disabled!"); } } else { dwmEnabled = false; dwmleft = 0; dwmtop = 0; dwmright = 0; dwmbottom = 0; //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; /// /// /// 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); } 继承以上窗体自动实现无边框窗体阴影功能
2、全透明或半透明窗体实现
public partial class Form1 : LdwmForm { public Form1() { InitializeComponent(); dwmleft = 10000;//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 = 10000; dwmright = 10000; dwmbottom = 10000; } protected override void OnPaint(PaintEventArgs e) { base.OnPaint(e); e.Graphics.FillRectangle(new SolidBrush(Color.FromArgb(50, 255, 0, 0)), this.ClientRectangle);//这里实现窗体半透明 } } 
这是半透明窗体