using System;using System.Collections.Generic;using System.ComponentModel;using System.Drawing;using System.Drawing.Drawing2D;using System.Linq;using System.Text;using System.Windows.Forms;namespace LC.Component{    public class cpPanel : System.Windows.Forms.Panel    {        private Color _borderColor = Color.FromArgb(23, 169, 254);           private int _radius = 10;        private RoundStyle _roundeStyle;        private const int WM_PAINT = 0xF;         public cpPanel() : base()           {           }        /// <summary>        /// 建立圆角路径的样式。        /// </summary>        public enum RoundStyle        {            /// <summary>            /// 四个角都不是圆角。            /// </summary>            None = 0,            /// <summary>            /// 四个角都为圆角。            /// </summary>            All = 1,            /// <summary>            /// 左边两个角为圆角。            /// </summary>            Left = 2,            /// <summary>            /// 右边两个角为圆角。            /// </summary>            Right = 3,            /// <summary>            /// 上边两个角为圆角。            /// </summary>            Top = 4,            /// <summary>            /// 下边两个角为圆角。            /// </summary>            Bottom = 5,        }        /// <summary>        /// 建立带有圆角样式的路径。        /// </summary>        /// <param name="rect">用来建立路径的矩形。</param>        /// <param name="_radius">圆角的大小。</param>        /// <param name="style">圆角的样式。</param>        /// <param name="correction">是否把矩形长宽减 1,以便画出边框。</param>        /// <returns>建立的路径。</returns>        GraphicsPath CreatePath(Rectangle rect, int radius, RoundStyle style, bool correction)        {            GraphicsPath path = new GraphicsPath();            int radiusCorrection = correction ? 1 : 0;            switch (style)            {                case RoundStyle.None:                    path.AddRectangle(rect);                    break;                case RoundStyle.All:                    path.AddArc(rect.X, rect.Y, radius, radius, 180, 90);                    path.AddArc(rect.Right - radius - radiusCorrection, rect.Y, radius, radius, 270, 90);                    path.AddArc(rect.Right - radius - radiusCorrection, rect.Bottom - radius - radiusCorrection, radius, radius, 0, 90);                    path.AddArc(rect.X, rect.Bottom - radius - radiusCorrection, radius, radius, 90, 90);                    break;                case RoundStyle.Left:                    path.AddArc(rect.X, rect.Y, radius, radius, 180, 90);                    path.AddLine(rect.Right - radiusCorrection, rect.Y, rect.Right - radiusCorrection, rect.Bottom - radiusCorrection);                    path.AddArc(rect.X, rect.Bottom - radius - radiusCorrection, radius, radius, 90, 90);                    break;                case RoundStyle.Right:                    path.AddArc(rect.Right - radius - radiusCorrection, rect.Y, radius, radius, 270, 90);                    path.AddArc(rect.Right - radius - radiusCorrection, rect.Bottom - radius - radiusCorrection, radius, radius, 0, 90);                    path.AddLine(rect.X, rect.Bottom - radiusCorrection, rect.X, rect.Y);                    break;                case RoundStyle.Top:                    path.AddArc(rect.X, rect.Y, radius, radius, 180, 90);                    path.AddArc(rect.Right - radius - radiusCorrection, rect.Y, radius, radius, 270, 90);                    path.AddLine(rect.Right - radiusCorrection, rect.Bottom - radiusCorrection, rect.X, rect.Bottom - radiusCorrection);                    break;                case RoundStyle.Bottom:                    path.AddArc(rect.Right - radius - radiusCorrection, rect.Bottom - radius - radiusCorrection, radius, radius, 0, 90);                    path.AddArc(rect.X, rect.Bottom - radius - radiusCorrection, radius, radius, 90, 90);                    path.AddLine(rect.X, rect.Y, rect.Right - radiusCorrection, rect.Y);                    break;            }            path.CloseFigure(); //这句很关键，缺少会没有左边线。            return path;        }        [DefaultValue(typeof(Color), "23, 169, 254"), Description("控件边框颜色")]           public Color BorderColor           {               get { return _borderColor; }               set                {                    _borderColor = value;                   base.Invalidate();               }           }             [DefaultValue(typeof(int), "10"), Description("圆角弧度大小")]           public int Radius           {               get { return _radius; }               set              {                   _radius = value;                   base.Invalidate();               }           }        public RoundStyle RoundeStyle        {            get { return _roundeStyle; }            set            {                _roundeStyle = value;                base.Invalidate();            }        }        protected override void WndProc(ref Message m)           {               try              {                   base.WndProc(ref m);                   if (m.Msg == WM_PAINT)                   {                       if (this.Radius > 0)                       {                           using (Graphics g = Graphics.FromHwnd(this.Handle))                           {                               Rectangle r = new Rectangle();                               r.Width = this.Width;                               r.Height = this.Height;                            DrawBorder(g, r, this.RoundeStyle, this.Radius);                        }                       }                   }               }               catch(Exception ex)               {                   MessageBox.Show(ex.Message);               }           }        private void DrawBorder(Graphics g, Rectangle rect, RoundStyle roundStyle, int radius)        {            rect.Width -= 1;            rect.Height -= 1;            using (GraphicsPath path = CreatePath(rect, radius, roundStyle, false))            {                using (Pen pen = new Pen(this.BorderColor))                {                    g.DrawPath(pen, path);                }            }        }     }}