(一) 添加一個一般處理程序，

<%@ WebHandler Language="C#" Class="show" %>using System; using System.Web; using System.Drawing;//引用 using System.Web.SessionState;//IRequiresSessionState的命名空間public class show : IHttpHandler, IRequiresSessionState {public void ProcessRequest(HttpContext context){context.Response.ContentType = "image/jpeg";//要輸出的類型Bitmap img = new Bitmap(50, 20);//造空白圖Graphics gr = Graphics.FromImage(img);//往哪個圖上去繪制Font font = new Font("宋體", 12, FontStyle.Bold);//設置字體SolidBrush brush = new SolidBrush(Color.White);//設置刷子gr.FillRectangle(brush, 0, 0, 50, 20);//刷子繪制的形狀brush.Color = Color.Red;//顏色string s = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";string str = "";Random rand = new Random();//初始化隨機數for (int i = 0; i < 4; i++){int start = rand.Next(62); //生成一個隨機的起始位置str += s.Substring(start, 1).ToString();}//需要繼承接口context.Session["yanzheng"] = str;gr.DrawString(str, font, brush, 0, 0);//繪制完了圖片了//將圖片保存，通過response響應流保存 img.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);}public bool IsReusable{get{return false;}}}

（二）制作一個主頁面 Default

添加一個imagebutton , textbox ,button

不要忘記在imageUrl中添加寫的圖片的方法。

using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls;public partial class _Default : System.Web.UI.Page {protected void Page_Load(object sender, EventArgs e){}protected void Button1_Click(object sender, EventArgs e){string txtyanzheng = TextBox1.Text;if (string.IsNullOrWhiteSpace(txtyanzheng)){}else{string yanzheng = Session["yanzheng"].ToString(); //用Session傳值接收過來if (txtyanzheng == yanzheng){Response.Write("<script>alert('注冊成功')</script>");}else{Response.Write("<script>alert('驗證碼不正確')</script>");}}}}

效果圖：

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轉載于:https://www.cnblogs.com/w-wz/p/4661432.html

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