C#通过重写Panel改变边框颜色与宽度的方法

using System;using System.Collections.Generic;using System.Text;using System.Runtime.InteropServices;using System.ComponentModel;using System.Windows.Forms;using System.Drawing;namespace ImageStudio{ public class PanelEx : System.Windows.Forms.Panel {  [DllImport("user32.dll")]  private static extern IntPtr GetWindowDC(IntPtr hwnd);  [DllImport("user32.dll")]  private static extern int ReleaseDC(IntPtr hwnd, IntPtr hdc);  private Color _borderColor = Color.Black;  private int _borderWidth = 1;  //  // 摘要:  //  获取或设置控件的边框颜色。  //  // 返回结果:  //  控件的边框颜色 System.Drawing.Color。默认为 System.Drawing.Color.Black  //  属性的值。  [Description("组件的边框颜色。"), Category("Appearance")]  public Color BorderColor  {   get   {    return _borderColor;   }   set   {    _borderColor = value;    this.Invalidate();   }  }  //  // 摘要:  //  获取或设置控件的边框宽度。  //  // 返回结果:  //  控件的边框宽度 int。默认为 1  //  属性的值。  [Description("组件的边框宽度。"), Category("Appearance")]  public int BorderWidth  {   get   {    return _borderWidth;   }   set   {    _borderWidth = value;    this.Invalidate();   }  }  public PanelEx()  {   SetStyle(ControlStyles.DoubleBuffer, true);   SetStyle(ControlStyles.AllPaintingInWmPaint, false);   SetStyle(ControlStyles.ResizeRedraw, true);   SetStyle(ControlStyles.UserPaint, true);   SetStyle(ControlStyles.SupportsTransparentBackColor, true);   this.Paint+=new PaintEventHandler(PanelEx_Paint);  }  private void PanelEx_Paint(object sender, PaintEventArgs e)  {   if (this.BorderStyle == BorderStyle.FixedSingle)   {    IntPtr hDC = GetWindowDC(this.Handle);    Graphics g = Graphics.FromHdc(hDC);    ControlPaint.DrawBorder(     g,     new Rectangle(0, 0, this.Width, this.Height),     _borderColor,     _borderWidth,     ButtonBorderStyle.Solid,     _borderColor,     _borderWidth,     ButtonBorderStyle.Solid,     _borderColor,     _borderWidth,     ButtonBorderStyle.Solid,     _borderColor,     _borderWidth,     ButtonBorderStyle.Solid);    g.Dispose();    ReleaseDC(Handle, hDC);   }  } }}