图片验证码制作

default.aspx里：包含点击图片更新的js代码

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default3.aspx.cs" Inherits="Default3" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
        <asp:Image ID="Image1" runat="server" ImageUrl="YZM.aspx" />
        <asp:Button ID="Button1" runat="server" Text="Button" />
        <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
    </div>
    </form>
</body>
</html>
<script>//点击图片更新
    var a = 0;
    document.getElementById("Image1").onclick = function ()
    {
        this.setAttribute("src","yzm.aspx?id="+a);
        a++;
    }


</script>

default.cs里：验证相同的按钮事件写在这里

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;


public partial class Default3 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Button1.Click += Button1_Click;
    }

    void Button1_Click(object sender, EventArgs e)//验证是否相同
    {
        string t1 = TextBox1.Text;
        string t2 = Session["yzm"].ToString();
        if (t1.ToUpper() == t2.ToUpper())
        {
            Label1.Text = "验证成功";
        }
        else
        { Label1.Text = "验证失败"; }
    }
}

YZM.aspx.cs里：主要的绘制，生成写在这里

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;

public partial class YZM : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Bitmap img = new Bitmap(70, 30);
        Graphics g = Graphics.FromImage(img);//绘制
        Random r = new Random();

        List<Color> clist = new List<Color>();//设定颜色集合
        clist.Add(Color.Yellow);
        clist.Add(Color.Black);
        clist.Add(Color.Blue);
        clist.Add(Color.Green);
        clist.Add(Color.Pink);
        clist.Add(Color.Orange);

        for (int i = 0; i < 10; i++)
        {
            Color cl = clist[r.Next(0, clist.Count)];//随机选取颜色
            Pen pe = new Pen(new SolidBrush(cl),r.Next(1,5));//随机生成颜色,随机生成线的粗细
            g.DrawLine(pe, new PointF(r.Next(0, 70), r.Next(0, 30)), new PointF(r.Next(0, 70), r.Next(0, 30)));//随机生成线
        }

        string all = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";//设定验证码集合
        string s = "";
        
        for (int i = 0; i < 4; i++)//随机生成四位验证码
        {
            s += all.Substring(r.Next(1,all.Length),1);
        }
        Session["yzm"] = s;//设置全局变量，用于验证调用
        

       

        g.DrawString(s, new Font("微软雅黑", 15), new SolidBrush(Color.Red), new PointF(5, 5));//绘制验证码

        img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Png);//输出流
　　　　　　
　　　　 response.end();
    }
}

 

posted @ 2017-01-07 16:52  游称  阅读(173)  评论(0)  编辑  收藏  举报