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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    
<title>无标题页</title>
</head>
<body>
    
<form id="form1" runat="server">
    
<div>
    
    
</div>
    
</form>
</body>
</html>
ValidateCode.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;

public partial class ValidateCode : System.Web.UI.Page
{
    
protected void Page_Load(object sender, EventArgs e)
    {
        
string checkCode = CreateRandomCode(4);
        Session[
"CheckCode"= checkCode;
        CreateImage(checkCode);
    }

    
private string CreateRandomCode(int codeCount)
    {
        
string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z";
        
string[] allCharArray = allChar.Split(',');
        
string randomCode = "";
        
int temp = -1;

        Random rand 
= new Random();
        
for (int i = 0; i < codeCount; i++)
        {
            
if (temp != -1)
            {
                rand 
= new Random(i * temp * ((int)DateTime.Now.Ticks));
            }
            
int t = rand.Next(35);
            
if (temp == t)
            {
                
return CreateRandomCode(codeCount);
            }
            temp 
= t;
            randomCode 
+= allCharArray[t];
        }
        
return randomCode;
    }

    
private void CreateImage(string checkCode)
    {
        
int iwidth = (int)(checkCode.Length * 11.5);
        System.Drawing.Bitmap image 
= new System.Drawing.Bitmap(iwidth, 20);
        Graphics g 
= Graphics.FromImage(image);
        Font f 
= new System.Drawing.Font("Arial"10, System.Drawing.FontStyle.Bold);
        Brush b 
= new System.Drawing.SolidBrush(Color.White);
        
//g.FillRectangle(new System.Drawing.SolidBrush(Color.Blue),0,0,image.Width, image.Height);
        g.Clear(Color.Blue);
        g.DrawString(checkCode, f, b, 
33);

        Pen blackPen 
= new Pen(Color.Black, 0);
        Random rand 
= new Random();
        
for (int i = 0; i < 5; i++)
        {
            
int y = rand.Next(image.Height);
            g.DrawLine(blackPen, 
0, y, image.Width, y);
        }

        System.IO.MemoryStream ms 
= new System.IO.MemoryStream();
        image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
        Response.ClearContent();
        Response.ContentType 
= "image/Jpeg";
        Response.BinaryWrite(ms.ToArray());
        g.Dispose();
        image.Dispose();
    }
}

引用页代码:

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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    
<title>无标题页</title>
</head>
<body>
    
<form id="form1" runat="server">
    
<div>
        
<asp:Image ID="Image1" runat="server" ImageUrl="ValidateCode.aspx" /></div>
    
</form>
</body>
</html>
截图:
完整代码下载: asp.net实现验证码
posted on 2007-05-20 20:41  Travelling  阅读(219)  评论(0编辑  收藏  举报