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后台文件:
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using System;
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using System.Data;
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using System.Configuration;
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using System.Collections;
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using System.Drawing;
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using System.Web;
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using System.Web.Security;
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using System.Web.UI;
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using System.Web.UI.WebControls;
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using System.Web.UI.WebControls.WebParts;
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using System.Web.UI.HTMLControls;
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public partial class Default2 : System.Web.UI.Page
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{
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protected void Page_Load(object sender, EventArgs e)
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{
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if(!this.IsPostBack)
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{
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this.GenImg(this.GenCode(4));
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}
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}
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//产生随机字符串
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private string GenCode(int num)
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{
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string[] source=
{"0","1","2","3","4","5","6","7","8","9",
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"A","B","C","D","E","F","G","H","I","J","K","L","M","N",
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"O","P","Q","R","S","T","U","V","W","X","Y","Z"};
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string code="";
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Random rd=new Random();
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for(int i=0;i < num;i++)
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{
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code += source[rd.Next(0,source.Length)];
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}
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return code;
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}
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//生成图片
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private void GenImg(string code)
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{
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Bitmap myPalette = new Bitmap(60, 20);//定义一个画板
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Graphics gh = Graphics.FromImage(myPalette);//在画板上定义绘图的实例
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Rectangle rc = new Rectangle(0, 0, 60, 20);//定义一个矩形
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gh.FillRectangle(new SolidBrush(Color.Blue), rc);//填充矩形
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gh.DrawString(code, new Font("宋体", 16), new SolidBrush(Color.White), rc);//在矩形内画出字符串
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myPalette.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);//将图片显示出来
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Session["ValidateCode"] = code;//将字符串保存到Session中,以便需要时进行验证
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gh.Dispose();
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myPalette.Dispose();
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}
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}
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HTML文件:2
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加入一个HTML控件Image即可
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<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.ASPx.cs" Inherits="Default2" %>
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<img src="Default2.ASPx" />
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