//把文字转换成图片
            if (!string.IsNullOrEmpty(present_no)) //如果文字不为空
            {
                try
                {
                    if (!Directory.Exists(@sinpath))
                    {
                        Directory.CreateDirectory(@sinpath); //用于存在图片的路径不存在，则先生成。
                    }
                    //图片对象  初始化图片的宽度与高度           
                    System.Drawing.Bitmap image = new System.Drawing.Bitmap(150, 30);
                    //画板
                    Graphics g = Graphics.FromImage(image);
                    //文本样式
                    //Font font = new System.Drawing.Font(“Arial”, 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
                    Font font = new System.Drawing.Font(“Arial”, 10, (System.Drawing.FontStyle.Regular));
                    //文本颜色与纹理
                    //System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0,0, image.Width, image.Height), Color.Red, Color.Red,0, true);
                    SolidBrush drawBrush = new SolidBrush(Color.Red); //文字颜色
                    g.FillRectangle(new SolidBrush(Color.White), 0, 0, image.Width, image.Height);

                    //g.DrawString(wordstring要绘制的文本, font, brush, 2, 2);
                    //image.Save(filename保存路径)
                    g.DrawString(pnName, font, drawBrush, 5, 5);
                    string path = sinpath + “\\” + present_no + “.jpg”;
                    image.Save(path, System.Drawing.Imaging.ImageFormat.Jpeg);
                }
                catch (Exception ex)
                {
                    throw ex;                   
                }

       }