Question

我正在开发一个asp.net Web应用程序，我正在尝试构建一个具有login.aspx和login.aspx.cs的简单登录页面。

aspx页面

<%@ Page Title="Log In" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"
    CodeBehind="Login.aspx.cs" Inherits="nikeeWebApplication.Account.Login" culture="auto" meta:resourcekey="PageResource1" uiculture="auto" %>

<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">
</asp:Content>
<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">

    <asp:Login ID="LoginUser" runat="server" EnableViewState="False" 
        RenderOuterTable="False" meta:resourcekey="LoginUserResource1">
        <LayoutTemplate>
            <span class="failureNotification">
                <asp:Literal ID="FailureText" runat="server" 
                meta:resourcekey="FailureTextResource1"></asp:Literal>
            </span>
            <asp:ValidationSummary ID="LoginUserValidationSummary" runat="server" CssClass="failureNotification" 
                 ValidationGroup="LoginUserValidationGroup" 
                meta:resourcekey="LoginUserValidationSummaryResource1"/>
            <div class="accountInfo">
                <fieldset class="login">
                    <legend>LOG IN</legend>
                    <p>
                        <asp:Label ID="UserNameLabel" runat="server" AssociatedControlID="UserName" 
                            meta:resourcekey="UserNameLabelResource1">Username:</asp:Label>
                        <asp:TextBox ID="UserName" runat="server" CssClass="textEntry" 
                            meta:resourcekey="UserNameResource1"></asp:TextBox>
                        <asp:RequiredFieldValidator ID="UserNameRequired" runat="server" ControlToValidate="UserName" 
                             CssClass="failureNotification" ErrorMessage="User Name is required." ToolTip="User Name is required." 
                             ValidationGroup="LoginUserValidationGroup" 
                            meta:resourcekey="UserNameRequiredResource1">*</asp:RequiredFieldValidator>
                    </p>
                    <p>
                        <asp:Label ID="PasswordLabel" runat="server" AssociatedControlID="Password" 
                            meta:resourcekey="PasswordLabelResource1">Password:</asp:Label>
                        <asp:TextBox ID="Password" runat="server" CssClass="passwordEntry" 
                            TextMode="Password" meta:resourcekey="PasswordResource1"></asp:TextBox>
                        <asp:RequiredFieldValidator ID="PasswordRequired" runat="server" ControlToValidate="Password" 
                             CssClass="failureNotification" ErrorMessage="Password is required." ToolTip="Password is required." 
                             ValidationGroup="LoginUserValidationGroup" 
                            meta:resourcekey="PasswordRequiredResource1">*</asp:RequiredFieldValidator>
                    </p>

                </fieldset>
                <p class="submitButton">
                    <asp:Button ID="LoginButton" runat="server" CommandName="Login" Text="Log In" 
                        ValidationGroup="LoginUserValidationGroup" 
                        meta:resourcekey="LoginButtonResource1"/>
                </p>
            </div>
        </LayoutTemplate>
    </asp:Login>
</asp:Content>

cs page

  using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.Configuration;
using System.Data.SqlClient; 

namespace nikeeWebApplication.Account
{
    public partial class Login : System.Web.UI.Page
    {
        SqlConnection con = new SqlConnection(WebConfigurationManager.ConnectionStrings["myConnectionString"].ConnectionString);
        protected void Page_Load(object sender, EventArgs e)
        {

        }
        protected void LoginButton_Click(object sender, EventArgs e)
        {
            con.Open();
            SqlCommand cmd = new SqlCommand("select * from UserMaster where UserName =@username and Password=@password", con);

            cmd.Parameters.AddWithValue("@username", UserName.Text);
            cmd.Parameters.AddWithValue("@password", Password.Text);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            da.Fill(dt);
            if (dt.Rows.Count > 0)
            {
                Response.Redirect("Details.aspx");
            }
            else
            {
                ClientScript.RegisterStartupScript(Page.GetType(), "validation", "<script language='javascript'>alert('Invalid Username and Password')</script>");
            }
        }
    }
}

但是当我从登录页面访问文本框时，它会给出错误。

图像描述如下所示。

感谢您的帮助

Answer 1

您需要访问以下文本框：

TextBox Password = LoginUser.FindControl("Password") as TextBox;
TextBox UserName = LoginUser.FindControl("UserName") as TextBox;

cmd.Parameters.AddWithValue("@username", UserName.Text);
cmd.Parameters.AddWithValue("@password", Password.Text);

或者您可以使用：

cmd.Parameters.AddWithValue("@username", LoginUser.UserName);
cmd.Parameters.AddWithValue("@password", LoginUser.Password);

再次，为了摆脱DataTable错误，添加using语句：

using System.Data;

无法访问从aspx到cs的字段ID

1 个答案: