C#实现位图转换成图标的方法

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace WindowsApplication2
{
  public partial class Form23 : Form
  {
    public Form23()
    {
      InitializeComponent();
    }
    private void button1_Click(object sender, EventArgs e)
    {
      Bitmap bmp = new Bitmap(@"d:/我的文档/桌面/ico/watermark.bmp");
      IntPtr hIcon = bmp.GetHicon();
      Icon icon=Icon.FromHandle(hIcon);
      this.Icon = icon;
      Graphics g = this.CreateGraphics();
      //g.DrawIcon(icon, this.ClientRectangle);
      g.DrawIconUnstretched(icon, this.ClientRectangle);
    }
  }
}