将字符串写入图片

将字符串写入到图片中.

1 换行采用指定写入位置来实现

2 务必释放资源,否则会出现Win32Error 

 

 protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                //前一页面传递过来的参数
                string email = Request.QueryString.Get("email");
                string realName = new OLUserService.OLUserService().GetRealNameByEmail(email);
                string workid = new OLUserService.OLUserService().GetWorkIdByEmail(email);

                //image1图片控件-呈现写入字符串后的图片
                string fileName = this.image1.ImageUrl;
                int index = fileName.LastIndexOf(".");

                string newFileName = fileName.Substring(0, index) + "_" + realName + fileName.Substring(index);
                FileInfo fileInfo = new FileInfo(Server.MapPath(fileName));
                fileInfo.CopyTo(Server.MapPath(newFileName), true);

                System.Drawing.Image image = new Bitmap(Server.MapPath(newFileName));
                Graphics g = Graphics.FromImage(image);
                
                string s2 = string.Format("通过了关于《集团商业行为准则》的{0}", DateTime.Now.ToString("yyyy"));
                string s3 = "年度认证，特此证明。";

                Font drawFont = new Font("Arial", 12);
                SolidBrush drawBrush = new SolidBrush(Color.Black);
                
                //通过指定写入位置实现换行功能
                drawPoint = new PointF(50, 200);
                g.DrawString(s2, drawFont, drawBrush, drawPoint);

                drawPoint = new PointF(50, 230);
                g.DrawString(s3, drawFont, drawBrush, drawPoint);
               

                System.Drawing.Image img = new Bitmap(image);
                //此处尤为重要,使用资源后的释放.否则会出现Win32错误

                //[ExternalException (0x80004005): A generic error occurred in GDI+.]

                g.Dispose();
                image.Dispose();

                img.Save(Server.MapPath(newFileName), System.Drawing.Imaging.ImageFormat.Jpeg);
                this.image1.ImageUrl = newFileName;
            }
        }