{

Bitmap nbitmap = new Bitmap(1000, 1000);

Graphics g = Graphics.FromImage(nbitmap);

Font font = new Font(FontFamily.GenericSansSerif, 10, FontStyle.Italic);

Brush brush = Brushes.Black;

g.DrawString("测试字符串", font, brush, 10, 10);/////运行到这句报参数无效

g.Dispose();

font.Dispose();

brush.Dispose();

nbitmap.Save(context.Server.MapPath("~/upload/cert" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".jpg"));

nbitmap.Dispose();

}