C# 开发圆角控件(窗体)

最近在做卡片视图的程序，要求将控件做成带有圆角的效果，下面是我在网上查找的资料，经过测试，确定可以实现功能。其中方法三既适应于控件，也适应于窗体。

先上传效果图：

方法一：

增加命名空间:using System.Drawing.Drawing2D;  
添加方法如下:当然各角的点可根据需要确定.

 private void Type(Control sender, int p_1, double p_2)
         {
             GraphicsPath oPath = new GraphicsPath();
             oPath.AddClosedCurve(
                 new Point[] {
             new Point(, sender.Height / p_1),
             new Point(sender.Width / p_1, ),
             new Point(sender.Width - sender.Width / p_1, ),
             new Point(sender.Width, sender.Height / p_1),
             new Point(sender.Width, sender.Height - sender.Height / p_1),
             new Point(sender.Width - sender.Width / p_1, sender.Height),
             new Point(sender.Width / p_1, sender.Height),
             new Point(, sender.Height - sender.Height / p_1) },

                 (float)p_2);

             sender.Region = new Region(oPath);
         }

在窗体的paint和resize事件中增加:Type(this,20,0.1);  
参数20和0.1也可以根据自己的需要调整到最佳效

方法二：

 public void SetWindowRegion()
         {

             System.Drawing.Drawing2D.GraphicsPath FormPath;

             FormPath = new System.Drawing.Drawing2D.GraphicsPath();

             Rectangle rect = new Rectangle(, , this.Width, this.Height - );//this.Left-10,this.Top-10,this.Width-10,this.Height-10);                 

             FormPath = GetRoundedRectPath(rect, );

             this.Region = new Region(FormPath);

         }

         private GraphicsPath GetRoundedRectPath(Rectangle rect, int radius)
         {

             int diameter = radius;

             Rectangle arcRect = new Rectangle(rect.Location, new Size(diameter, diameter));

             GraphicsPath path = new GraphicsPath();

             //   左上角   

             path.AddArc(arcRect, , );

             //   右上角   

             arcRect.X = rect.Right - diameter;

             path.AddArc(arcRect, , );

             //   右下角   

             arcRect.Y = rect.Bottom - diameter;

             path.AddArc(arcRect, , );

             //   左下角   

             arcRect.X = rect.Left;

             path.AddArc(arcRect, , );

             path.CloseFigure();

             return path;

         }

在窗体的resize事件中增加:SetWindowRegion();

方法三：通过Window系统API行数，修改控件和窗体为椭圆形状。代码如下所示：

 [System.Runtime.InteropServices.DllImport("gdi32")]
         private static extern IntPtr BeginPath(IntPtr hdc);
         [System.Runtime.InteropServices.DllImport("gdi32")]
         private static extern int SetBkMode(IntPtr hdc, int nBkMode);
         const int TRANSPARENT = ;
         [System.Runtime.InteropServices.DllImport("gdi32")]
         private static extern IntPtr EndPath(IntPtr hdc);
         [System.Runtime.InteropServices.DllImport("gdi32")]
         private static extern IntPtr PathToRegion(IntPtr hdc);
         [System.Runtime.InteropServices.DllImport("gdi32")]
         private static extern int Ellipse(IntPtr hdc, int x1, int y1, int x2, int y2);
         [System.Runtime.InteropServices.DllImport("user32")]
         private static extern IntPtr SetWindowRgn(IntPtr hwnd, IntPtr hRgn, bool bRedraw);
         [System.Runtime.InteropServices.DllImport("user32")]
         private static extern IntPtr GetDC(IntPtr hwnd);

 protected override void OnPaint(PaintEventArgs e)
         {
             base.OnPaint(e);

             IntPtr dc;
             IntPtr region;

             dc = GetDC(this.Handle);
             BeginPath(dc);
             SetBkMode(dc, TRANSPARENT);
             Ellipse(dc, , , this.Width - , this.Height - );
             EndPath(dc);
             region = PathToRegion(dc);
             SetWindowRgn(this.Handle, region, false);
         }