if (!Page.IsPostBack)

{

    try

    {

        string str = Server.MapPath("~/upload/test.jpg");

        System.Drawing.Image myImage = System.Drawing.Image.FromFile(str);

        Bitmap map = new Bitmap(myImage);

        myImage.Dispose();

        Graphics graphics = Graphics.FromImage(map);

        graphics.InterpolationMode = InterpolationMode.HighQualityBilinear;

        SolidBrush brush = new SolidBrush(Color.Red);

        PointF P = new PointF(, );

        Font font = new Font("宋体", );

        graphics.DrawString("guwei4037", font, brush, P);

        map.Save(str.Substring(, str.LastIndexOf("\\") + ) + "new" + str.Substring(str.LastIndexOf("\\") + , str.LastIndexOf(".") - str.LastIndexOf("\\") - ) + str.Substring(str.LastIndexOf("."), str.Length - str.LastIndexOf(".")), ImageFormat.Jpeg);

        font.Dispose();

        graphics.Dispose();

    }

    catch { }

}