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.

 1 private void Type(Control sender, int p_1, double p_2)
 2         {
 3             GraphicsPath oPath = new GraphicsPath();
 4             oPath.AddClosedCurve(
 5                 new Point[] {
 6             new Point(0, sender.Height / p_1),
 7             new Point(sender.Width / p_1, 0), 
 8             new Point(sender.Width - sender.Width / p_1, 0), 
 9             new Point(sender.Width, sender.Height / p_1),
10             new Point(sender.Width, sender.Height - sender.Height / p_1), 
11             new Point(sender.Width - sender.Width / p_1, sender.Height), 
12             new Point(sender.Width / p_1, sender.Height),
13             new Point(0, sender.Height - sender.Height / p_1) },
14 
15                 (float)p_2);
16 
17             sender.Region = new Region(oPath);
18         }

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：

 1 public void SetWindowRegion()
 2         {
 3 
 4             System.Drawing.Drawing2D.GraphicsPath FormPath;
 5 
 6             FormPath = new System.Drawing.Drawing2D.GraphicsPath();
 7 
 8             Rectangle rect = new Rectangle(0, 22, this.Width, this.Height - 22);//this.Left-10,this.Top-10,this.Width-10,this.Height-10);                 
 9 
10             FormPath = GetRoundedRectPath(rect, 30);
11 
12             this.Region = new Region(FormPath);
13 
14         }
15 
16         private GraphicsPath GetRoundedRectPath(Rectangle rect, int radius)
17         {
18 
19             int diameter = radius;
20 
21             Rectangle arcRect = new Rectangle(rect.Location, new Size(diameter, diameter));
22 
23             GraphicsPath path = new GraphicsPath();
24 
25             //   左上角   
26 
27             path.AddArc(arcRect, 180, 90);
28 
29             //   右上角   
30 
31             arcRect.X = rect.Right - diameter;
32 
33             path.AddArc(arcRect, 270, 90);
34 
35             //   右下角   
36 
37             arcRect.Y = rect.Bottom - diameter;
38 
39             path.AddArc(arcRect, 0, 90);
40 
41             //   左下角   
42 
43             arcRect.X = rect.Left;
44 
45             path.AddArc(arcRect, 90, 90);
46 
47             path.CloseFigure();
48 
49             return path;
50 
51         }

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：

 1 [System.Runtime.InteropServices.DllImport("gdi32")]
 2         private static extern IntPtr BeginPath(IntPtr hdc);
 3         [System.Runtime.InteropServices.DllImport("gdi32")]
 4         private static extern int SetBkMode(IntPtr hdc, int nBkMode);
 5         const int TRANSPARENT = 1;
 6         [System.Runtime.InteropServices.DllImport("gdi32")]
 7         private static extern IntPtr EndPath(IntPtr hdc);
 8         [System.Runtime.InteropServices.DllImport("gdi32")]
 9         private static extern IntPtr PathToRegion(IntPtr hdc);
10         [System.Runtime.InteropServices.DllImport("gdi32")]
11         private static extern int Ellipse(IntPtr hdc, int x1, int y1, int x2, int y2);
12         [System.Runtime.InteropServices.DllImport("user32")]
13         private static extern IntPtr SetWindowRgn(IntPtr hwnd, IntPtr hRgn, bool bRedraw);
14         [System.Runtime.InteropServices.DllImport("user32")]
15         private static extern IntPtr GetDC(IntPtr hwnd);

 1 protected override void OnPaint(PaintEventArgs e)
 2         {
 3             base.OnPaint(e);
 4 
 5             IntPtr dc;
 6             IntPtr region;
 7 
 8             dc = GetDC(this.Handle);
 9             BeginPath(dc);
10             SetBkMode(dc, TRANSPARENT);
11             Ellipse(dc, 0, 0, this.Width - 3, this.Height - 2);
12             EndPath(dc);
13             region = PathToRegion(dc);
14             SetWindowRgn(this.Handle, region, false);
15         }