C#实现登录验证码 ashx
2007-11-21 10:18
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代码如下：
／／／首先新建一个ValidateCode.ashx文件．
using System;
using System.Data;
using System.Web;
using System.Collections;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Drawing;
namespace WebApplication3
{
/// <summary>
/// Summary description for $codebehindclassname$
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class ValidateCode : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
context.Response.Cache.SetCacheability(HttpCacheability.NoCache);///特别注意，如不加，单击验证图片＇看不清换一张＇，无效果．
this.CreateCheckCodeImage(GenerateCheckCode(context),context);
}
public bool IsReusable
{
get
{
return false;
}
}
private string GenerateCheckCode(HttpContext context)
{
int number;
char code;
string checkCode = String.Empty;
System.Random random = new Random();
for (int i = 0; i < 6; i++)
{
number = random.Next();
if (number % 2 == 0)
code = (char)('0' + (char)(number % 10));
else if (number % 3 == 0)
code = (char)('A' + (char)(number % 26));
else
code = (char)('a' + (char)(number % 26));
checkCode += code.ToString();
}
context.Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));／／／你也可以存到Seesion里．
return checkCode;
}
private void CreateCheckCodeImage(string checkCode, HttpContext context)
{
if (checkCode == null || checkCode.Trim() == String.Empty)
return;
System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
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);
context.Response.ClearContent();
context.Response.ContentType = "image/Gif";
context.Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
}
}
／／／再实现一个登陆界面
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="WebApplication3._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>登录界面</title>
</head>
<body>
<form id="form1" runat="server">
<div>
用户名：<asp:TextBox ID="txt_user" runat="server"></asp:TextBox>
<br />
密 码：<asp:TextBox ID="txt_pwd" runat="server" TextMode="Password"></asp:TextBox><br />
验证码：
<asp:TextBox ID="txtCheckCode" runat="server"></asp:TextBox>
<img src="ValidateCode.ashx" onclick="this.src='ValidateCode.ashx'" title="看不清换一张" />
<asp:Label ID="lblMessage" runat="server"></asp:Label>
<br />
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="登录" /></div>
</form>
</body>
</html>
///登录页隐藏代码如下：
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;
namespace WebApplication3
{
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
if (Request.Cookies["CheckCode"] == null)
{
lblMessage.Text = "您的浏览器设置已被禁用 Cookies，您必须设置浏览器允许使用 Cookies 选项后才能使用本系统。";
lblMessage.Visible = true;
return;
}
if (String.Compare(Request.Cookies["CheckCode"].Value, txtCheckCode.Text, true) != 0)
{
lblMessage.Text = "验证码错误，请输入正确的验证码。";
lblMessage.Visible = true;
return;
}
///在这执行下一步
///如果你的CheckCode是存到Session里的话，代码如下：
//if (Session["CheckCode"] != null)
//{
// if (String.Compare(Session["CheckCode"].ToString(), txtCheckCode.Text.Trim(), true) != 0)
// {
// lblMessage.Text = "验证码错误，请输入正确的验证码。";
// lblMessage.Visible = true;
// return;
// }
// else
// {
///在这执行下一步
// }
//}
}
}
}
／／／首先新建一个ValidateCode.ashx文件．
using System;
using System.Data;
using System.Web;
using System.Collections;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Drawing;
namespace WebApplication3
{
/// <summary>
/// Summary description for $codebehindclassname$
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class ValidateCode : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
context.Response.Cache.SetCacheability(HttpCacheability.NoCache);///特别注意，如不加，单击验证图片＇看不清换一张＇，无效果．
this.CreateCheckCodeImage(GenerateCheckCode(context),context);
}
public bool IsReusable
{
get
{
return false;
}
}
private string GenerateCheckCode(HttpContext context)
{
int number;
char code;
string checkCode = String.Empty;
System.Random random = new Random();
for (int i = 0; i < 6; i++)
{
number = random.Next();
if (number % 2 == 0)
code = (char)('0' + (char)(number % 10));
else if (number % 3 == 0)
code = (char)('A' + (char)(number % 26));
else
code = (char)('a' + (char)(number % 26));
checkCode += code.ToString();
}
context.Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));／／／你也可以存到Seesion里．
return checkCode;
}
private void CreateCheckCodeImage(string checkCode, HttpContext context)
{
if (checkCode == null || checkCode.Trim() == String.Empty)
return;
System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
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);
context.Response.ClearContent();
context.Response.ContentType = "image/Gif";
context.Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
}
}
／／／再实现一个登陆界面
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="WebApplication3._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>登录界面</title>
</head>
<body>
<form id="form1" runat="server">
<div>
用户名：<asp:TextBox ID="txt_user" runat="server"></asp:TextBox>
<br />
密 码：<asp:TextBox ID="txt_pwd" runat="server" TextMode="Password"></asp:TextBox><br />
验证码：
<asp:TextBox ID="txtCheckCode" runat="server"></asp:TextBox>
<img src="ValidateCode.ashx" onclick="this.src='ValidateCode.ashx'" title="看不清换一张" />
<asp:Label ID="lblMessage" runat="server"></asp:Label>
<br />
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="登录" /></div>
</form>
</body>
</html>
///登录页隐藏代码如下：
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;
namespace WebApplication3
{
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
if (Request.Cookies["CheckCode"] == null)
{
lblMessage.Text = "您的浏览器设置已被禁用 Cookies，您必须设置浏览器允许使用 Cookies 选项后才能使用本系统。";
lblMessage.Visible = true;
return;
}
if (String.Compare(Request.Cookies["CheckCode"].Value, txtCheckCode.Text, true) != 0)
{
lblMessage.Text = "验证码错误，请输入正确的验证码。";
lblMessage.Visible = true;
return;
}
///在这执行下一步
///如果你的CheckCode是存到Session里的话，代码如下：
//if (Session["CheckCode"] != null)
//{
// if (String.Compare(Session["CheckCode"].ToString(), txtCheckCode.Text.Trim(), true) != 0)
// {
// lblMessage.Text = "验证码错误，请输入正确的验证码。";
// lblMessage.Visible = true;
// return;
// }
// else
// {
///在这执行下一步
// }
//}
}
}
}
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