从代码隐藏文件中访问文本框，标签等

Question

我有一个Web窗体页面，其中包含一个标签和两个文本框，我想在页面的代码后面访问文件，但是当我在代码中调用文本框时在文件后面，红色的波浪线显示在标签和文本框的下面。我已经尝试了类似问题中提到的解决方案（重新生成设计器文件，确保在其他页面中没有多个文本框/标签具有相同的名称，创建一个新的aspx页并重新编写代码），但没有一个已经解决了这个范围问题。这段代码昨晚编译得很好，从那时起我就没有改变代码，也没有编译。

我对C＃比较陌生，所以我可能会错过一些非常明显的事情，对此我很抱歉。

在Login.aspx.cs：

protected void btnCreateUser_Click(object sender, EventArgs e) 
//this is called in an asp:button's OnClick 
{ 
    string loginUsername = txtBxUsername_Login.Text;//red line on txtBxUsername_Login 
    string loginPassword = txtBxPassword_Login.Text;//red line on txtBxPasswprd_Login 

    if (loginUsername != null && loginUsername != "" & loginPassword != null && loginPassword != "") 
    { 
     WebSecurity.Login(loginUsername, loginPassword, false); 
     lblLoginResponse.Text = "TO DO: Proper login response";//red line on lblLoginResponse 
    } 
} 

在为Login.aspx：

<asp:Content ID="BodyContent" ContentPlaceHolderID="PageContent" runat="server"> 
    <div class="row"> 
     <div class="content-large"> 
      <%-- This section tag contains all account validation controls, buttons, textboxes and labels --%> 
      <section id="loginForm"> 
       <div class="form-horizontal"> 
        <h2><%: Title %></h2> 
        <h4>Use a local account to login: </h4> 
        <hr /> 
        <asp:PlaceHolder runat="server" ID="ErrorMessage" Visible="false"> 
         <p class="text-danger"> 
          <asp:Literal runat="server" ID="failureText" /> 
         </p> 
        </asp:PlaceHolder> 
        <div class="form-group"> 
         <div class="text-box-container"> 
          <asp:Label ID="lblUsername" runat="server" Text="Username"></asp:Label> 
          <asp:TextBox ID="txtBxUsername_Login" runat="server"></asp:TextBox> 
         </div> 
        </div> 
        <div class="form-group"> 
         <div class="text-box-container"> 
          <asp:Label ID="lblPassword" runat="server" Text="Password"></asp:Label> 
          <asp:TextBox ID="txtBxPassword_Login" runat="server"></asp:TextBox> 
         </div> 
        </div> 
        <div class="form-group"> 
         <asp:Button ID="btnRegister" runat="server" Text="Log in" OnClick="btnLogin_Click" /> 
         <asp:Label runat="server" ID="lblLoginResponse" /> 
        </div> 
       </div> 
      </section> 
     </div> 
    </div> 
</asp:Content> 

的Login.aspx.designer.cs文件：

//------------------------------------------------------------------------------ 
// <auto-generated> 
//  This code was generated by a tool. 
// 
//  Changes to this file may cause incorrect behavior and will be lost if 
//  the code is regenerated. 
// </auto-generated> 
//------------------------------------------------------------------------------ 

namespace inft3970.Account { 

    public partial class Login { 

     /// <summary> 
     /// ErrorMessage control. 
     /// </summary> 
     /// <remarks> 
     /// Auto-generated field. 
     /// To modify move field declaration from designer file to code-behind file. 
     /// </remarks> 
     protected global::System.Web.UI.WebControls.PlaceHolder ErrorMessage; 

     /// <summary> 
     /// failureText control. 
     /// </summary> 
     /// <remarks> 
     /// Auto-generated field. 
     /// To modify move field declaration from designer file to code-behind file. 
     /// </remarks> 
     protected global::System.Web.UI.WebControls.Literal failureText; 

     /// <summary> 
     /// lblUsername control. 
     /// </summary> 
     /// <remarks> 
     /// Auto-generated field. 
     /// To modify move field declaration from designer file to code-behind file. 
     /// </remarks> 
     protected global::System.Web.UI.WebControls.Label lblUsername; 

     /// <summary> 
     /// txtBxUsername_Login control. 
     /// </summary> 
     /// <remarks> 
     /// Auto-generated field. 
     /// To modify move field declaration from designer file to code-behind file. 
     /// </remarks> 
     protected global::System.Web.UI.WebControls.TextBox txtBxUsername_Login; 

     /// <summary> 
     /// lblPassword control. 
     /// </summary> 
     /// <remarks> 
     /// Auto-generated field. 
     /// To modify move field declaration from designer file to code-behind file. 
     /// </remarks> 
     protected global::System.Web.UI.WebControls.Label lblPassword; 

     /// <summary> 
     /// txtBxPassword control. 
     /// </summary> 
     /// <remarks> 
     /// Auto-generated field. 
     /// To modify move field declaration from designer file to code-behind file. 
     /// </remarks> 
     protected global::System.Web.UI.WebControls.TextBox txtBxPassword_Login; 

     /// <summary> 
     /// btnRegister control. 
     /// </summary> 
     /// <remarks> 
     /// Auto-generated field. 
     /// To modify move field declaration from designer file to code-behind file. 
     /// </remarks> 
     protected global::System.Web.UI.WebControls.Button btnRegister; 

     /// <summary> 
     /// lblLoginResponse control. 
     /// </summary> 
     /// <remarks> 
     /// Auto-generated field. 
     /// To modify move field declaration from designer file to code-behind file. 
     /// </remarks> 
     protected global::System.Web.UI.WebControls.Label lblLoginResponse; 

     /// <summary> 
     /// btnCreateUser control. 
     /// </summary> 
     /// <remarks> 
     /// Auto-generated field. 
     /// To modify move field declaration from designer file to code-behind file. 
     /// </remarks> 
     protected global::System.Web.UI.WebControls.Button btnCreateUser; 
    } 
} 

Answer 1

你叫您的密码框ID="txtBxPassword"在html中，但在您的代码后面试图访问它作为txtBxPassword_Login

Answer 2

当您自动向页面添加新项目时，代码将被添加到另一个带有.designer.cs的文件中，例如，当您将标签放在default.aspx页面上时，您应该在默认页面上看到以下代码。 aspx.designer.cs：

/// <summary> 
    /// Label1 control. 
    /// </summary> 
    /// <remarks> 
    /// Auto-generated field. 
    /// To modify move field declaration from designer file to code-behind file. 
    /// </remarks> 
    protected global::System.Web.UI.WebControls.Label Label1; 

有时设计师不会添加此代码，因此在此代码背后的代码中未定义。