本程序功能是使用Session将用户输入的用户名保存在Session中(登录成功情况下，登录失败不会有Session值)，其它页面想访问时会先判断是否有之前存的Session值。
登录Login.htm页面:
<head>
<title></title>
<script type="text/javascript">
//刷新验证码
function refreshYZM() {
var imgYZM = document.getElementById("imgYZM");
imgYZM.src = "YanZhengMa.ashx?t="+new Date();
}
</script>
</head>
<body>
<form action="Login.ashx" method="post">
<table>
<tr><td>用户名</td><td><input type="text" name="username" /></td></tr>
<tr><td>密码</td><td><input type="password" name="password" /></td></tr>
<tr>
<td>
<img src="YanZhengMa.ashx" id="imgYZM" onclick="refreshYZM()" />
</td><td><input type="text" name="yzm" />
</td>
</tr>
<tr><td><input type="submit" name="btnLogin" value="登录" /></td><td>@msg</td></tr>
</table>
</form>
</body>
</html>
生成验证码YanZhengMa.ashx:
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "image/jpeg";
Random rand = new Random();
int num = rand.Next(1000, 10000);//生成4位随机数
string code = num.ToString();
context.Session[Login.YZM] = code;
using (Bitmap bmp = new Bitmap(45, 25))
{
using (Graphics g = Graphics.FromImage(bmp))
using (Font font = new Font(FontFamily.GenericSerif, 15))
{
g.DrawString(code, font, Brushes.Red, new PointF(0, 0));
}
bmp.Save(context.Response.OutputStream, ImageFormat.Jpeg);
}
}
登录Login.ashx页在(必须实现IRequiresSessionState接口，在using System.Data.SqlClient;命名空间下)：
public const string YZM = "YZM";//存储验证码
public const string LOGINUSERNAME = "LoginUserName";//将登录用户名存到Session，供多个页面访问
public const string LOGINURL = "LoginUrl";//尝试登录的时候的页面地址
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/html";
string btnLogin = context.Request["btnLogin"];//获取点击按钮
string html = CommonHelper.ReadHtml("~/Login.htm");//获取Login.htm页面内容
if (string.IsNullOrEmpty(btnLogin))//判断按钮是否点击
{
html = html.Replace("@msg", "");
context.Response.Write(html);
}
else
{
string yzm = context.Request["yzm"];//获取用户输入的验证码
string yzmInServer = (string)context.Session[YZM];//获取服务器的验证码
if (yzm != yzmInServer)//判断用户输入与服务器的验证码
{
html = html.Replace("@msg","<font color=red>验证验错误</font>");
context.Response.Write(html);
return;
}
string username = context.Request["username"];
string password = context.Request["password"];
int r = (int)SQLHelper.ExecuteScalar("select count(*) from Users where [email protected] and [email protected]",
new SqlParameter { ParameterName = "@name", Value = username },
new SqlParameter { ParameterName = "@password", Value = password });
if (r <= 0)
{
html = html.Replace("@msg", "<font color=red>用户名或密码错误</font>");
context.Response.Write(html);
return;
}
else
{
//如果登录成功
context.Session[LOGINUSERNAME] = username;//把当前登录的用户名写到Session中
//获取上一次访问网址的Session值,在QueryYuE.ashx和ChangePassword.ashx中已作判断，
//当没登录时，就设置Session值"LOGINURL"为要访问的页面
string navUrl = (string)context.Session[LOGINURL];
if (navUrl != null)
{
context.Response.Redirect(navUrl);//重定向回到上一次访问的页面，动态获取
}
else
{
context.Response.Write("看，美丽的图片。。。。。");
}
}
}
}
修改密码ChangePassword.ashx(须实现IRequiresSessionState)：
public void ProcessRequest(HttpContext context)
{
string username = (string)context.Session[Login.LOGINUSERNAME];//获取登录时存入的Session值
if (username == null)//如果没登录强制性的访问此页面，则重定向到登陆页面
{
context.Session[Login.LOGINURL] = context.Request.Url.ToString();//把当前地址存到Session中
context.Response.Redirect("Login.ashx");
}
else
{
context.Response.Write("修改密码。。。，当前登录用户<a href=‘Loginout.ashx‘>退出登录</a>" + username);
}
}
余额查询QueryYuE.ashx(须实现IRequiresSessionState):
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/html";
string username = (string)context.Session[Login.LOGINUSERNAME];
if (username == null)//如果没登录强制性的访问此页面，则重定向到登陆页面
{
context.Session[Login.LOGINURL] = context.Request.Url.ToString();//把当前地址存到Session中
context.Response.Redirect("Login.ashx");
}
else
{
context.Response.Write("查询余额。。。，当前登录用户。<a href=‘Loginout.ashx‘>退出登录</a>" + username);
}
}
退出登录Loginout.ashx(须实现IRequiresSessionState):
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/html";
context.Session.Abandon();//销毁Session
context.Response.Redirect("Login.ashx");
}
帮助类CommonHelper.cs:
public class CommonHelper
{
public static string ReadHtml(string path)
{
string fillPath = HttpContext.Current.Server.MapPath(path);
string html = File.ReadAllText(fillPath);
return html;
}
}
时间： 2024-11-03 22:21:25