which line gives you the error? what is in your aspx page? the code looks fine assuming you did everything right in other places except the following two linesstring mySel="SELECT count(*) as iCount from user where UserID=""+userid+""";mySel="SELECT * from user where UserID=""+userid+""";===>string mySel="SELECT count(*) as iCount from user where UserID='"+userid+"'";mySel="SELECT * from user where UserID='"+userid+"'";

解决方案 »

  1.   

    我把所有的代码都贴出来吧,
    -------------------------------------------------------------
    index.aspx
    <%@ Page language="c#" Inherits="lsj.WebForm1" SRC="default.cs"%>
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
    <HTML>
    <HEAD>
    <meta name="GENERATOR" Content="Microsoft Visual Studio 7.0">
    <meta name="CODE_LANGUAGE" Content="C#">
    <meta name="vs_defaultClientScript" content="JavaScript (ECMAScript)">
    <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
    </HEAD>
    <body MS_POSITIONING="GridLayout">
    <FONT face="宋体">
    <form runat="server" ID="Form1">
    <asp:Label id="Label1" style="Z-INDEX: 101; LEFT: 82px; POSITION: absolute; TOP: 39px" runat="server" Width="55px" 
    Height="26px">登录名</asp:Label>
    <asp:Label id="Label2" style="Z-INDEX: 102; LEFT: 80px; POSITION: absolute; TOP: 84px" runat="server" Width="63px" Height="24px">密 码</asp:Label>
    <asp:TextBox id="Userid" style="Z-INDEX: 103; LEFT: 161px; POSITION: absolute; TOP: 39px" runat="server" Width="109px" Height="25px"></asp:TextBox>
    <asp:TextBox id="Pwd" style="Z-INDEX: 104; LEFT: 162px; POSITION: absolute; TOP: 81px" runat="server" Width="109px" Height="22px" TextMode="Password"></asp:TextBox>
    <asp:Button id="LogButton" style="Z-INDEX: 105; LEFT: 79px; POSITION: absolute; TOP: 125px" runat="server" Width="59px" Height="25px" Text="登 录"></asp:Button>
    <asp:Label id="Msg" style="Z-INDEX: 106; LEFT: 161px; POSITION: absolute; TOP: 130px" runat="server" Width="117px" Height="26px"></asp:Label>
    <asp:RequiredFieldValidator id="RequiredFieldValidator1" style="Z-INDEX: 107; LEFT: 290px; POSITION: absolute; TOP: 43px" runat="server" Width="162px" Height="18px" ErrorMessage="RequiredFieldValidator" ControlToValidate="Userid">请输入登录名!</asp:RequiredFieldValidator>
    <asp:RequiredFieldValidator id="RequiredFieldValidator2" style="Z-INDEX: 108; LEFT: 292px; POSITION: absolute; TOP: 83px" runat="server" Width="175px" Height="22px" ErrorMessage="RequiredFieldValidator" ControlToValidate="Pwd">请输入登录密码!</asp:RequiredFieldValidator>
    </form>
    </FONT>
    </body>
    </HTML>
    ------------------------------------------------------------------default.csusing System;
    using System.Collections;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Web;
    using System.Web.SessionState;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Web.UI.HtmlControls;
    using System.Data.OleDb;namespace lsj
    {
     /// <summary>
     /// Summary description for WebForm1.
     /// </summary>
     public class WebForm1 : System.Web.UI.Page
     {
      protected System.Web.UI.WebControls.Label Label1;
      protected System.Web.UI.WebControls.Label Label2;
      protected System.Web.UI.WebControls.TextBox Userid;
      protected System.Web.UI.WebControls.Button LogButton;  
      protected System.Web.UI.WebControls.TextBox Pwd;
      protected System.Web.UI.WebControls.Label Msg;
      protected System.Web.UI.HtmlControls.HtmlForm Form1;  
      protected System.Web.UI.WebControls.RequiredFieldValidator rfvUserid;
      protected System.Web.UI.WebControls.RequiredFieldValidator rfvPwd;
      public string strConnection;
      OleDbConnection myConn;  public WebForm1()
      {
       Page.Init += new System.EventHandler(Page_Init);
      }  private void Page_Load(object sender, System.EventArgs e)
      { 
      }  private void Page_Init(object sender, EventArgs e)
      {
    InitializeComponent();
    string strConnection="Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+Server.MapPath(".")+"..\\user.mdb;"; 
    //user.mdb放在与aspx文件同一目录下 
    myConn=new OleDbConnection(strConnection);
      }  private void InitializeComponent()
      {    
    this.LogButton.Click += new System.EventHandler(this.LogButton_Click);
    this.Load += new System.EventHandler(this.Page_Load);
      }  private void LogButton_Click(object sender, System.EventArgs e)
      {    
    string userid,pwd;
    userid=Userid.Text;
    pwd=Pwd.Text;   
    string mySel="SELECT count(*) as iCount from user where UserID=""+userid+""";
        
    OleDbCommand myCmd1=new OleDbCommand(mySel,myConn);
    myCmd1.Connection.Open();
    OleDbDataReader Dr1;
    Dr1=myCmd1.ExecuteReader();
    Dr1.Read();
    string Count=Dr1["iCount"].ToString();
    Dr1.Close();
    myCmd1.Connection.Close();
    string DrPwd,DrRoles;
    if(Count!="0")
    {
     mySel="SELECT * from user where UserID=""+userid+""";
     OleDbCommand myCmd=new OleDbCommand(mySel,myConn);
     myCmd.Connection.Open();
     OleDbDataReader Dr;
     Dr=myCmd.ExecuteReader();
     Dr.Read();
     DrPwd=Dr["Password"].ToString();
     Dr.Close();
     if(DrPwd==pwd)
     {
      Session["logid"]=userid;//新建一个Session
      Response.Redirect("main.aspx");
     }
      else
      Msg.Text="登录密码错.";
    }
    else
      Msg.Text="没有这个用户.";
      }
     }
    }