c# winForm 圓角Panel

using System;

using System.Collections.Generic;

using System.Text;

using System.Windows.Forms;

using System.Drawing;

using System.Drawing.Drawing2D;

namespace RoundPanel

{

    class RoundPanel : Panel

    {

        private int mMatrixRound = 8;

        private Color mBack;

        public Color Back

        {

             get { return mBack; }

            set

            {

                if (value == null)

                {

                     mBack = Control.DefaultBackColor;

                }

                else

                {

                     mBack = value;

                }

                base.Refresh();

            }

        }

        public int MatrixRound

        {

             get { return mMatrixRound; }

            set

            {

                mMatrixRound = value;

                base.Refresh();

            }

        }

        private GraphicsPath CreateRound(Rectangle rect, int radius)

        {

            GraphicsPath roundRect = new GraphicsPath();

//頂端

            roundRect.AddLine(rect.Left + radius - 1, rect.Top - 1, rect.Right - radius, rect.Top - 1);             

//右上角

roundRect.AddArc(rect.Right - radius, rect.Top - 1, radius, radius, 270, 90);

//右邊

            roundRect.AddLine(rect.Right, rect.Top + radius, rect.Right, rect.Bottom - radius);

            //右下角

            roundRect.AddArc(rect.Right - radius, rect.Bottom - radius, radius, radius, 0, 90);

//底邊

            roundRect.AddLine(rect.Right - radius, rect.Bottom, rect.Left + radius, rect.Bottom);

            //左下角

roundRect.AddArc(rect.Left - 1, rect.Bottom - radius, radius, radius, 90, 90);

//左邊

            roundRect.AddLine(rect.Left - 1, rect.Top + radius, rect.Left - 1, rect.Bottom - radius);

//左上角

            roundRect.AddArc(rect.Left - 1, rect.Top - 1, radius, radius, 180, 90);

            return roundRect;

        }

        protected override void OnPaint(PaintEventArgs e)

        {

            int width = base.Width - base.Margin.Left - base.Margin.Right;

            int height = base.Height - base.Margin.Top - base.Margin.Bottom;

            Rectangle rec = new Rectangle(base.Margin.Left, base.Margin.Top, width, height);

            GraphicsPath round = CreateRound(rec, mMatrixRound);

             e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;

             e.Graphics.FillPath((Brush)(new SolidBrush(mBack)), round);

        }

        protected override void OnResize(EventArgs eventargs)

        {

             base.Refresh();

        }

    }

}

轉載于:https://www.cnblogs.com/hfzsjz/archive/2010/08/13/1799062.html