在按钮上绘制图片

using System;
using System.Drawing;
using System.Windows.Forms;

namespace 在button上绘制图片
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
this.button1.Click+=new EventHandler(button1_Click);
this.button1.Paint+=new PaintEventHandler(button1_Paint);
}
Bitmap bm;
private void button1_Click(object sender, EventArgs e)
{
OpenFileDialog of = new OpenFileDialog();
of.InitialDirectory = @"E:\";
of.Filter = "图片文件|*.jpg;*.png;*.gif";
if (of.ShowDialog() == DialogResult.OK && of.FileName != "")
{
bm = new Bitmap(of.FileName);
this.Invalidate();//使当前操作区域无效，并导致重绘事件
}
}

private void button1_Paint(object sender, PaintEventArgs e)
{
if (bm != null)
{
Graphics g=e.Graphics;
TextureBrush b=new TextureBrush(bm);
Button bt = (Button)sender;
bt.Width = bm.Width;
bt.Height = bm.Height;
if (this.Width < bm.Width)
{
this.Width = (int)(bm.Width * 1.3);
}
if (this.Height < bm.Height)
{
this.Height = (int)(bm.Height*1.3);
}
g.FillRectangle(b, this.ClientRectangle);
}
}
}
}