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

            g.FillPath(br1, gpath1);//绘制按钮

            g.FillPath(br3, gpath3);//绘制顶部白色泡泡

            //设定内存位图对象，进行二级缓存绘图操作

            btnrc = new Rectangle(rc1.Location, rc1.Size);

            btnbmp = new Bitmap(btnrc.Width, btnrc.Height);

            Graphics g_bmp = Graphics.FromImage(btnbmp);

            g_bmp.SmoothingMode = SmoothingMode.AntiAlias;

            g_bmp.FillPath(br1, gpath1);

            g_bmp.FillPath(br3, gpath3);

            //将region赋值给button

            Region rgn = new Region(gpath1);

            rgn.Union(gpath2);

            this.Region = rgn;

            //绘制按钮的文本

            GraphicsPath gpath4 = new GraphicsPath();

            RectangleF gpath1bounds = gpath1.GetBounds();

            Rectangle rcText = new Rectangle((int)gpath1bounds.X + btnOff, (int)gpath1bounds.Y + btnOff, (int)gpath1bounds.Width,

                (int)gpath1bounds.Height);

            StringFormat strFormat = new StringFormat();

            strFormat.Alignment = StringAlignment.Center;

            strFormat.LineAlignment = StringAlignment.Center;//横竖都居中

            gpath4.AddString(this.Text, this.Font.FontFamily, (int)this.Font.Style, this.Font.Size, rcText, strFormat);

            Pen txtPen = new Pen(this.ForeColor, 1);

            g.DrawPath(txtPen, gpath4);

            g_bmp.DrawPath(txtPen, gpath4);

        }

        protected override void OnMouseDown(MouseEventArgs mevent)

        {

            if (mevent.Button == MouseButtons.Left)

            {

                this.mouseActionType = MouseActionType.Click;

                this.Invalidate();

            }

            base.OnMouseDown(mevent);

        }

        protected override void OnMouseUp(MouseEventArgs mevent)

        {

            this.mouseActionType = MouseActionType.Hover;

            this.Invalidate();

            base.OnMouseUp(mevent);

        }

        protected override void OnMouseHover(EventArgs e)

        {

            this.mouseActionType = MouseActionType.Hover;

            this.Invalidate();

            base.OnMouseHover(e);

        }

        protected override void OnMouseEnter(EventArgs e)

        {

            this.mouseActionType = MouseActionType.Hover;

            this.Invalidate();

            base.OnMouseEnter(e);

        }

        protected override void OnMouseLeave(EventArgs e)//鼠标离开事件

        {

            this.mouseActionType = MouseActionType.None;

            this.Invalidate();

            base.OnMouseLeave(e);

        }

    }

}