//===============a.ashx代码如下:========================
<%@ WebHandler Language="C#" Class="ValidateImageHandler" %>
using System;
using System.Web;
using System.Web.SessionState;
using System.Drawing;
using System.Drawing.Imaging;
using System.Text;
using System.Data;
/// <summary>
/// ValidateImageHandler 生成网站验证码功能
/// </summary>
public class ValidateImageHandler : IHttpHandler, IRequiresSessionState
{
int intLength = 5; //长度
string strIdentify = "Identify"; //随机字串存储键值,以便存储到Session中
public ValidateImageHandler()
{
} /// <summary>
/// 生成验证图片核心代码
/// </summary>
/// <param name="hc"></param>
public void ProcessRequest(HttpContext hc)
{
//设置输出流图片格式
hc.Response.ContentType = "image/gif";
Bitmap b = new Bitmap(200, 60);
Graphics g = Graphics.FromImage(b);
g.FillRectangle(new SolidBrush(Color.YellowGreen), 0, 0, 200, 60);
Font font = new Font(FontFamily.GenericSerif, 42, FontStyle.Bold, GraphicsUnit.Pixel);
Random r = new Random(); //合法随机显示字符列表
string strLetters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
StringBuilder s = new StringBuilder();
//将随机生成的字符串绘制到图片上
for (int i = 0; i < intLength; i++)
{
s.Append(strLetters.Substring(r.Next(0, strLetters.Length - 1), 1));
g.DrawString(s[s.Length - 1].ToString(), font, new SolidBrush(Color.Blue), i * 38, r.Next(0, 15));
} //生成干扰线条
Pen pen = new Pen(new SolidBrush(Color.Blue), 2);
for (int i = 0; i < 10; i++)
{
g.DrawLine(pen, new Point(r.Next(0, 199), r.Next(0, 59)), new Point(r.Next(0, 199), r.Next(0, 59)));
}
b.Save(hc.Response.OutputStream, ImageFormat.Gif);
hc.Session[strIdentify] = s.ToString(); //先保存在Session中,验证与用户输入是否一致
//Response.Write(hc.Session[strIdentify]);
//Response.End();
hc.Response.End();
}
/// <summary>
/// 表示此类实例是否可以被多个请求共用(重用可以提高性能)
/// </summary>
public bool IsReusable
{
get
{
return true;
}
}
}
前台显示的页面b.aspx如下:
<img width="100px" height="25px" src="ValidateImageHandler.ashx"/>我怎么才能使用hc.Session[strIdentify] = s.ToString();中的数值?
<%@ WebHandler Language="C#" Class="ValidateImageHandler" %>
using System;
using System.Web;
using System.Web.SessionState;
using System.Drawing;
using System.Drawing.Imaging;
using System.Text;
using System.Data;
/// <summary>
/// ValidateImageHandler 生成网站验证码功能
/// </summary>
public class ValidateImageHandler : IHttpHandler, IRequiresSessionState
{
int intLength = 5; //长度
string strIdentify = "Identify"; //随机字串存储键值,以便存储到Session中
public ValidateImageHandler()
{
} /// <summary>
/// 生成验证图片核心代码
/// </summary>
/// <param name="hc"></param>
public void ProcessRequest(HttpContext hc)
{
//设置输出流图片格式
hc.Response.ContentType = "image/gif";
Bitmap b = new Bitmap(200, 60);
Graphics g = Graphics.FromImage(b);
g.FillRectangle(new SolidBrush(Color.YellowGreen), 0, 0, 200, 60);
Font font = new Font(FontFamily.GenericSerif, 42, FontStyle.Bold, GraphicsUnit.Pixel);
Random r = new Random(); //合法随机显示字符列表
string strLetters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
StringBuilder s = new StringBuilder();
//将随机生成的字符串绘制到图片上
for (int i = 0; i < intLength; i++)
{
s.Append(strLetters.Substring(r.Next(0, strLetters.Length - 1), 1));
g.DrawString(s[s.Length - 1].ToString(), font, new SolidBrush(Color.Blue), i * 38, r.Next(0, 15));
} //生成干扰线条
Pen pen = new Pen(new SolidBrush(Color.Blue), 2);
for (int i = 0; i < 10; i++)
{
g.DrawLine(pen, new Point(r.Next(0, 199), r.Next(0, 59)), new Point(r.Next(0, 199), r.Next(0, 59)));
}
b.Save(hc.Response.OutputStream, ImageFormat.Gif);
hc.Session[strIdentify] = s.ToString(); //先保存在Session中,验证与用户输入是否一致
//Response.Write(hc.Session[strIdentify]);
//Response.End();
hc.Response.End();
}
/// <summary>
/// 表示此类实例是否可以被多个请求共用(重用可以提高性能)
/// </summary>
public bool IsReusable
{
get
{
return true;
}
}
}
前台显示的页面b.aspx如下:
<img width="100px" height="25px" src="ValidateImageHandler.ashx"/>我怎么才能使用hc.Session[strIdentify] = s.ToString();中的数值?
<%@ Import Namespace="System.Web" %>
<%@ Import Namespace="System.Web.SessionState" %>
<%@ Import Namespace="System.Drawing" %>
<%@ Import Namespace="System.Drawing.Imaging" %>
<%@ Import Namespace="System.Data" %>
<script runat="server">
public class ValidateImageHandler : IHttpHandler, IRequiresSessionState
{
int intLength = 5; //长度
string strIdentify = "Identify"; //随机字串存储键值,以便存储到Session中
public void ProcessRequest(HttpContext hc)
{
//设置输出流图片格式
hc.Response.ContentType = "image/gif";
Bitmap b = new Bitmap(200, 60);
Graphics g = Graphics.FromImage(b);
g.FillRectangle(new SolidBrush(Color.YellowGreen), 0, 0, 200, 60);
Font font = new Font(FontFamily.GenericSerif, 42, FontStyle.Bold, GraphicsUnit.Pixel);
Random r = new Random();
//合法随机显示字符列表
string strLetters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
StringBuilder s = new StringBuilder();
//将随机生成的字符串绘制到图片上
for (int i = 0; i < intLength; i++)
{
s.Append(strLetters.Substring(r.Next(0, strLetters.Length - 1), 1));
g.DrawString(s[s.Length - 1].ToString(), font, new SolidBrush(Color.Blue), i * 38, r.Next(0, 15));
}
//生成干扰线条
Pen pen = new Pen(new SolidBrush(Color.Blue), 2);
for (int i = 0; i < 10; i++)
{
g.DrawLine(pen, new Point(r.Next(0, 199), r.Next(0, 59)), new Point(r.Next(0, 199), r.Next(0, 59)));
}
b.Save(hc.Response.OutputStream, ImageFormat.Gif);
hc.Session[strIdentify] = s.ToString(); //先保存在Session中,验证与用户输入是否一致
hc.Response.End();
}
public bool IsReusable
{
get
{
return true;
}
}
}
</script>
<!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>验证码</title>
</head>
<body>
<img width="100px" height="25px" src="ValidateImageHandler.ashx"/></body>
</html>
<%Response.Write("验证码="+Session["Identify"]);%>写出的是上一次的验证码
<%@ Import Namespace="System.Web" %>
<%@ Import Namespace="System.Web.SessionState" %>
<%@ Import Namespace="System.Drawing" %>
<%@ Import Namespace="System.Drawing.Imaging" %>
<%@ Import Namespace="System.Data" %>
<script runat="server">
public class ValidateImageHandler : IHttpHandler, IRequiresSessionState
{
int intLength = 5;
public void ProcessRequest(HttpContext hc)
{
//设置输出流图片格式
hc.Response.ContentType = "image/gif";
Bitmap b = new Bitmap(200, 60);
Graphics g = Graphics.FromImage(b);
g.FillRectangle(new SolidBrush(Color.YellowGreen), 0, 0, 200, 60);
Font font = new Font(FontFamily.GenericSerif, 42, FontStyle.Bold, GraphicsUnit.Pixel);
Random r = new Random();
//合法随机显示字符列表
string strLetters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
StringBuilder s = new StringBuilder();
hc.Session["Identify"] = s.ToString(); //先保存在Session中,验证与用户输入是否一致
//将随机生成的字符串绘制到图片上
for (int i = 0; i < intLength; i++)
{
s.Append(strLetters.Substring(r.Next(0, strLetters.Length - 1), 1));
g.DrawString(s[s.Length - 1].ToString(), font, new SolidBrush(Color.Blue), i * 38, r.Next(0, 15));
}
//生成干扰线条
Pen pen = new Pen(new SolidBrush(Color.Blue), 2);
for (int i = 0; i < 10; i++)
{
g.DrawLine(pen, new Point(r.Next(0, 199), r.Next(0, 59)), new Point(r.Next(0, 199), r.Next(0, 59)));
}
b.Save(hc.Response.OutputStream, ImageFormat.Gif);
}
public bool IsReusable
{
get
{
return true;
}
}
}
</script>
<%Response.Write("验证码="+Session["Identify"]);%>
<!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>验证码</title>
</head>
<body>
<form name="form1" method="post" action="1.aspx">
<img width="100px" height="25px" src="ValidateImageHandler.ashx"/>
<input type="text" name="textfield">
<input type="hidden" name="a" value="<%Response.Write(Session["Identify"]);%>">
<input type="submit" name="Submit" value="提交">
</form>
</body>
</html>