扩展GroupBox控件

public class GroupBoxEx : GroupBox   
    {   
        private Font _titleFont = new Font("宋体", 10, FontStyle.Regular);   
        private Color _titleColor = Color.Green;   
        private Color _borderColor = Color.FromArgb(23, 169, 254);   
        private int _radius = 10;   
        private int _tiltePos =10;   
  
        private const int WM_ERASEBKGND = 0x0014;   
        private const int WM_PAINT = 0xF;   
  
        public GroupBoxEx()   
            : base()   
        {   
        }   
  
        [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(Color), "Green"), Description("标题颜色")]   
        public Color TitleColor   
        {   
            get { return _titleColor; }   
            set  
            {   
                _titleColor = value;   
                base.Invalidate();   
            }   
        }   
  
        [DefaultValue(typeof(Font), ""), Description("标题字体设置")]   
        public Font TitleFont   
        {   
            get { return _titleFont; }   
            set  
            {   
                _titleFont = value;   
                base.Invalidate();   
            }   
        }   
  
  
        [DefaultValue(typeof(int), "30"), Description("圆角弧度大小")]   
        public int Radius   
        {   
            get { return _radius; }   
            set  
            {   
                _radius = value;   
                base.Invalidate();   
            }   
        }   
  
        [DefaultValue(typeof(int), "10"), Description("标题位置")]   
        public int TiltePos   
        {   
            get { return _tiltePos; }   
            set  
            {   
                _tiltePos = 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.Radius);   
                        }   
                    }   
                }   
            }   
            catch (Exception ex)   
            {   
                MessageBox.Show(ex.Message);   
            }   
        }   
  
        private void DrawBorder(Graphics g, Rectangle rect, int radius)   
        {   
            rect.Width -= 1;   
            rect.Height -= 1;   
  
  
            using (Pen pen = new Pen(this.BorderColor))   
            {   
                g.Clear(this.BackColor);   
                g.DrawString(this.Text, this.TitleFont, new SolidBrush(this.TitleColor), radius + this.TiltePos, 0);   
  
                g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;   
  
                GraphicsPath path = new GraphicsPath();   
  
                float height = g.MeasureString(this.Text, this.TitleFont).Height / 2;   
                float width = g.MeasureString(this.Text, this.TitleFont).Width;   
  
                path.AddArc(rect.X, rect.Y + height, radius, radius, 180, 90);//左上角弧线   
                  path.AddLine(radius, rect.Y + height, radius + this.TiltePos, rect.Y + height);   
  
                path.StartFigure();   
  
                path.AddLine(radius + this.TiltePos + width, rect.Y + height, rect.Right - radius, rect.Y + height);   
  
                path.AddArc(rect.Right - radius, rect.Y + height, radius, radius, 270, 90);//右上角弧线   
                  path.AddArc(rect.Right - radius, rect.Bottom - radius, radius, radius, 0, 90);   
                path.AddArc(rect.X, rect.Bottom - radius, radius, radius, 90, 90);   
  
                path.StartFigure();   
  
                path.AddArc(rect.X, rect.Y + height, radius, radius, -90, -90);//左上角弧线   
                  path.AddArc(rect.X, rect.Bottom - radius, radius, radius, -180, -90);   
  
  
                g.DrawPath(pen, path);   
            }   
        }   
    }