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);
   }
  }
 }
}