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完整asp.net图形验证码程序

2009-03-28 09:49 281 查看
1、测试页面:Default.aspx

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

<!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>ASP.NET验证码</title>

</head>

<body>

<form id="form1" runat="server">

<div>

请输入验证码:<input id="txtVI" type="text" name="view_id" runat="server" maxlength="5" size="5"/>

<asp:Image id="Image1" runat="server" ImageUrl="ValidateCode.aspx" ImageAlign="Middle" />

<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="您没有输入验证码" ControlToValidate="txtVI"></asp:RequiredFieldValidator><br />

<asp:Button ID="Button1" runat="server" Text="提 交" OnClick="Button1_Click" /></div>

</form>

</body>

</html>

2、测试页面后台:Default.aspx.cs

using System;

using System.Data;

using System.Configuration;

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;

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 VNum;

VNum = Session["VNum"].ToString();

Session.Abandon();

ViewState["VNum"] = VNum;

if (txtVI.Value == ViewState["VNum"].ToString())

{

Response.Write("<script>alert('验证码输入正确!');</script>");

return;

}

else

{

// VIWShow.Text="所填写的验证码不正确!";

Response.Write("<script>alert('验证码输入错误!');</script>");

return;

}

}

}

3、生成验证码页面:ValidateCode.aspx

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

4、生成验证码页面后台:

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;

/* Copyright all(c) 2005 ZhongFeng, http://blog.csdn.net/SW515 */

public partial class ValidateCode : System.Web.UI.Page

{

private void Page_Load(object sender, System.EventArgs e)

{

this.CreateCheckCodeImage(GenerateCheckCode());

}

#region Web 窗体设计器生成的代码

override protected void OnInit(EventArgs e)

{

//

// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。

//

InitializeComponent();

base.OnInit(e);

}

/// <summary>

/// 设计器支持所需的方法 - 不要使用代码编辑器修改

/// 此方法的内容。

/// </summary>

private void InitializeComponent()

{

this.Load += new System.EventHandler(this.Page_Load);

}

#endregion

private string GenerateCheckCode()

{

int number;

char code;

string checkCode = String.Empty;

System.Random random = new Random();

for (int i = 0; i < 5; i++)

{

number = random.Next();

if (number % 2 == 0)

code = (char)('0' + (char)(number % 10));

else

code = (char)('A' + (char)(number % 26));

checkCode += code.ToString();

}

Session["VNum"] = checkCode;

return checkCode;

}

private void CreateCheckCodeImage(string checkCode)

{

if (checkCode == null || checkCode.Trim() == String.Empty)

return;

System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);

System.Drawing.Graphics g = Graphics.FromImage(image);

try

{

//生成随机生成器

Random random = new Random();

//清空图片背景色

g.Clear(Color.White);

//画图片的背景噪音线

for (int i = 0; i < 25; i++)

{

int x1 = random.Next(image.Width);

int x2 = random.Next(image.Width);

int y1 = random.Next(image.Height);

int y2 = random.Next(image.Height);

g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);

}

Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));

System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);

g.DrawString(checkCode, font, brush, 2, 2);

//画图片的前景噪音点

for (int i = 0; i < 100; i++)

{

int x = random.Next(image.Width);

int y = random.Next(image.Height);

image.SetPixel(x, y, Color.FromArgb(random.Next()));

}

//画图片的边框线

g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);

System.IO.MemoryStream ms = new System.IO.MemoryStream();

image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);

Response.ClearContent();

Response.ContentType = "image/Gif";

Response.BinaryWrite(ms.ToArray());

}

finally

{

g.Dispose();

image.Dispose();

}

}

}
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