FileStream fs = new FileStream(Server.MapPath("images/DSC_0290.JPG"), FileMode.Open);//将图片文件存在文件流中

        long fslength = fs.Length;//流长度

        byte[] b1 = new byte[(int)fslength];//定义二进制数组

        fs.Read(b1, , (int)fslength);//将流中字节写入二进制数组中

        fs.Close();//关闭流

        //Response.ContentType = "image/jpeg";

        //Response.BinaryWrite(b1);//将图片输出在页面

        Response.Clear();

        Response.ContentType = "image/jpg";

        Response.BinaryWrite(b1);