using System;
using System.Drawing;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;

namespace GButton
{
    public partial class GZXButton : Button
    {
        private enum MouseActionType
        { 
            None,
            Hover,
            Click
         }
        private MouseActionType mouseActionType;
        private ImageAttributes imgattr = new ImageAttributes();//实例化一个图像属性类
        private Bitmap btnbmp;//定义一个位图
        private Rectangle btnrc;//定义一个矩形

        public GZXButton()
        {
            InitializeComponent();
            mouseActionType = MouseActionType.None;
            this.SetStyle(ControlStyles.AllPaintingInWmPaint|//禁止擦除背景
                ControlStyles.DoubleBuffer|//双缓冲
                ControlStyles.UserPaint,true);
            //下面这些可以不设置,也可以自己定义
            this.Font = new Font("Aial Black", 12, FontStyle.Bold);
            this.BackColor = Color.DarkTurquoise;
            this.Size = new Size(112, 48);
        }
        /// <summary>
        ///  按钮形状
        /// </summary>
        /// <param name="rc">按钮的坐标和大小</param>
        /// <param name="r">按钮圆弧的半径</param>
        /// <returns>返回按钮形状</returns>
        private GraphicsPath GetGraphicsPath(Rectangle rc, int r)
        {
            int x = rc.X, y = rc.Y, w = rc.Width, h = rc.Height;
            GraphicsPath gpath = new GraphicsPath();
            gpath.AddArc(x, y, r, r, 180, 90);//左上角圆弧
            gpath.AddArc(x + w - r, y, r, r, 270, 90);//右上角圆弧
            gpath.AddArc(x + w - r, y + h - r,r, r, 0, 90);//右下角圆弧
            gpath.AddArc(x, y + h - r, r, r, 90, 90);//左下角圆弧
            gpath.CloseFigure();//闭合
            return gpath;
        }
        protected override void OnPaint(PaintEventArgs pe)
        {
           // base.OnPaint(pe);
            Graphics g = pe.Graphics;//创建画布
            g.Clear(SystemColors.ButtonFace);//重置背景颜色,可以自定义
            Color clr = this.BackColor;
            int btnOff = 0;//按钮边距
            int shadowOff = 0;//阴影边距
            switch (mouseActionType)
            { 
                case MouseActionType.None:
                    break;
                case MouseActionType.Hover:
                    clr = Color.LightGray;
                    break;
                case MouseActionType.Click:
                    shadowOff = 4;
                    clr = Color.LightGray;
                    btnOff = 2;
                    break;
                default:
                    break;
            }
            g.SmoothingMode = SmoothingMode.AntiAlias;//消除锯齿
            //创建按钮本身的图形
            Rectangle rc1 = new Rectangle(btnOff, btnOff, this.ClientSize.Width - 8 - btnOff, this.ClientSize.Height - 8 - btnOff);
            GraphicsPath gpath1 = this.GetGraphicsPath(rc1, 20);
            LinearGradientBrush br1 = new LinearGradientBrush(new Point(0, 0), new Point(0, rc1.Height + 6), clr, Color.White);
            //创建按钮阴影
            Rectangle rc2 = rc1;
            rc2.Offset(shadowOff, shadowOff);
            GraphicsPath gpath2 = this.GetGraphicsPath(rc2, 20);
            PathGradientBrush br2 = new PathGradientBrush(gpath2);
            br2.CenterColor = Color.Black;
            br2.SurroundColors = new Color[] { SystemColors.ButtonFace };
            //为了更逼真，我们将渐变结束颜色设定为窗体前景色，可以根据窗口的前景颜色适当调整
            //创建按钮顶部白色渐变
            Rectangle rc3 = rc1;
            rc3.Inflate(-5, -5);
            rc3.Height = 15;
            GraphicsPath gpath3 = GetGraphicsPath(rc3, 20);
            LinearGradientBrush br3 = new LinearGradientBrush(rc3, Color.FromArgb(255, Color.White), Color.FromArgb(0, Color.White), LinearGradientMode.Vertical);
            //绘制图形
            g.FillPath(br2, gpath2);//绘制阴影