asp.net总结

生成验证码

   public class CreateCode : IHttpHandler

    {



        public void ProcessRequest(HttpContext context)

        {

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

            using (Bitmap bm = new Bitmap(80, 25))//画板 bitmap

            {

                using (Graphics gp = Graphics.FromImage(bm)) //画笔 graphics

                {

                   // gp.FillRectangle(Brushes.Red, 0, 0, bm.Width, bm.Height);    //填充画板，颜色，从某点开始 宽度高度

              //      gp.FillRectangle(Brushes.White, 1, 1, bm.Width - 2, bm.Height - 2);



                    gp.DrawString(MakeCode(), new Font("楷体", 12), Brushes.Yellow,22,5);

                    bm.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);//将这个画板输出

                }

            }

        }



        public string MakeCode()

        {

            string result = "";

            string ku = "0123456789abcdefghijklmnopqistuvwxyzABCDEFGHIJKLMNOPQISTUVWXYZ";

            Random ra = new Random();

            for (int i = 0; i < 4; i++)

            {

                result += ku[ra.Next(0, ku.Length)];

            }

            return result;

        }

画板Bitmap 画笔Graphic 控制颜色 Brushs 画字，颜色，开始xy，宽高