添加一般处理程序
<%@ WebHandler Language="C#" Class="yanzheng" %>
using System;
using System.Web;
using System.Web.SessionState;//IRequiresSessionState的命名空间
using System.Drawing;
public class yanzheng : IHttpHandler, IRequiresSessionState{
public void ProcessRequest (HttpContext context) {
context.Response.ContentType = "image/jpeg";//要输出的类型
Bitmap img = new Bitmap(50,20);//空白图，指定大小
Graphics gr = Graphics.FromImage(img);//往哪个图上绘制
Font font = new Font("宋体",12,FontStyle.Bold);//字体样式
SolidBrush brush = new SolidBrush(Color.White);//设置画笔
gr.FillRectangle(brush,0,0,50,20);//设置画笔绘制图形的形状
brush.Color = Color.Red;//绘制图形的颜色
string s = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";//随即字符数据源
string str = "";
Random r = new Random();
for (int i = 0; i < 4; i++)
{
int start = r.Next(62);
str += s.Substring(start,1).ToString();//取随机数，截取一位，组成4位验证码
}
context.Session["yanzheng"] = str;//会话中保存
gr.DrawString(str,font,brush,0,0);//绘制图形
//保存图片，通过Response响应流保存
img.Save(context.Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);
}
public bool IsReusable {
get {
return false;
}
}
}
界面
<body>
<form id="form1" runat="server" method="get">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<br />
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:TextBox ID="txtcode" runat="server"></asp:TextBox>
<asp:ImageButton ID="ImageButton1" runat="server" ImageUrl="yanzheng.ashx" OnClick="ImageButton1_Click" />
<br />
<asp:Button ID="btn_checkCode" runat="server" OnClick="btn_checkCode_Click" Text="验证" />
<br />
<asp:Label ID="Label1" runat="server"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
</body>
protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
{
ImageButton1.ImageUrl = "yanzheng.ashx?id="+new Random().Next(100);
}
protected void btn_checkCode_Click(object sender, EventArgs e)
{
string s1 = txtcode.Text.ToUpper();
string s2 = Session["yanzheng"].ToString().ToUpper();
if (s1==s2)
{
Label1.Text = "验证成功";
}
else
{
Response.Write("<script>alert(‘验证失败‘)</script>");
}
}
时间： 2024-12-20 13:28:18