急 ！c#项目的主界面做个更换背景的功能？？

Question

麻烦各位说清楚点呢@

Answer 1

用GDI画
//声明
private Image image = Image.FromFile(@"E:\标准.BMP");  //载入图片
        private RectangleF RtF;
  private void DrawImage()  //画图函数
        {
            try
            {
                Graphics g = this.CreateGraphics();
                g.DrawImage(image, RtF);
                g.Dispose();
            }
            catch
            { 
            }
        }
  private void Form1_Paint(object sender, PaintEventArgs e)
        {
            DrawImage();
        }
 private void button1_Click(object sender, EventArgs e)
        {
           image = Image.FromFile(@"E:\标准1.BMP");  //载入另一张图片
            try
            {
                RtF = new RectangleF(0, 0, this.Width, this.Height);
            }
        }