ASP.NET登陆验证例子
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>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<asp:Label ID="Label1" runat="server" Text="UserName"></asp:Label>
<asp:TextBox ID="tbUserName" runat="server" Height="22px" Width="128px"></asp:TextBox>
<br />
<asp:Label ID="Label2" runat="server" Text="PassPort"></asp:Label>
<asp:TextBox ID="tbPassPort" runat="server" EnableTheming="True"
TextMode="Password"></asp:TextBox>
<br />
ValidateCode<asp:TextBox ID="tbValidateCode" runat="server"
EnableTheming="True"></asp:TextBox>
<img width="100px" height="25px" src="ValidateImageHandler.ashx"/>
<br />
<asp:Button ID="btLogin" runat="server" onclick="btLogin_Click" Text="Login" />
<br />
<asp:Label ID="lblResult" runat="server"></asp:Label>
</form>
</body>
</html>
default.aspx.cs
using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Drawing;
using System.Data.SqlClient;
using System.Data.Common;
public partial class _Default : System.Web.UI.Page
{
SqlConnection m_Sqlconn;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
this.tbUserName.Text = "";
this.tbPassPort.Text = "";
}
DBConnect();
}
public static bool CheckCode(string text)
{
string txt = System.Web.HttpContext.Current.Session["strIdentify"] as string;
return text == txt;
}
protected void btLogin_Click(object sender, EventArgs e)
{
string l_strUserName = this.tbUserName.Text.Trim();
string l_strPassPort = this.tbPassPort.Text.Trim();
string l_strValidateCode = this.tbValidateCode.Text.Trim();
string l_sqlTemp = "select * from tbl_user where username = '" + l_strUserName + "' and [password] = '" + l_strPassPort + "'";
SqlCommand comm = new SqlCommand(l_sqlTemp, m_Sqlconn);
if (comm.ExecuteScalar() != null && CheckCode(l_strValidateCode))
{
this.lblResult.Text = "登陆成功";
}
else
{
//this.lblResult.Text = System.Web.HttpContext.Current.Session["strIdentify"] as string;
this.lblResult.Text="用户登录信息错误，请重新输入";
}
m_Sqlconn.Close();
}
public void DBConnect()
{
string conn = System.Configuration.ConfigurationSettings.AppSettings["DBConnectString"];// "Server=127.0.0.1;user id=sa;password=sa;DataBase=test";
m_Sqlconn = new SqlConnection(conn);
try
{
m_Sqlconn.Open();
}
catch(Exception e)
{
this.lblResult.Text = e.ToString();
}
}
}
ValidateImageHandler.ashx
<%@ WebHandler Language="C#" Class="ValidateImageHandler" %>
using System;
using System.Web;
using System.Web.SessionState;
using System.Drawing;
using System.Drawing.Imaging;
using System.Text;
/// <summary>
/// ValidateImageHandler 生成网站验证码功能
/// </summary>
public class ValidateImageHandler : IHttpHandler, IRequiresSessionState
{
int intLength = 4; //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, 48, 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 < 1; 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();
}
/// <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;
}
}
}
Web.config
<appSettings>
<add key="DBConnectString" value="Server=127.0.0.1;user id=sa;password=sa;DataBase=test"/>
</appSettings>
