加载页面

using Image = System.Drawing.Image;

在Page_Load里调用下面代码,然后直接调用这个页面的url就是生成的图片了.

Image image = Image.FromFile(Server.MapPath("~/background.png"));
            Graphics g = Graphics.FromImage(image);
            try
            {

                ///
                  ////操作image对象代码

                ///

                //保存图片并通过Response输出流

                Response.Clear();

                Response.ContentType = "image/png";

                image.Save(Response.OutputStream, ImageFormat.Png);

            }

            finally
            {
                g.Dispose();
                image.Dispose();

            }

                image.Save(Response.OutputStream, ImageFormat.Png);

            }

            finally
            {
                g.Dispose();
                image.Dispose();

            }