Question

First time I am writing some ASP.NET code and stumbled upon a weird bug. When I click the button to post, it does so, but without any params.

Code:

<%@ Page Title="" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="Login.aspx.cs" Inherits="SingTelAPI.Login" %>
<asp:Content ID="Content1" ContentPlaceHolderID="HeadContent" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <table style="width:100%;">
        <tr>
            <td>
                &nbsp;</td>
            <td>
                &nbsp;</td>
            <td>
                &nbsp;</td>
        </tr>
        <tr>
            <td>
                &nbsp;</td>
            <td>
                <table style="width:100%;">
                    <tr>
                        <td>
                            &nbsp;</td>
                        <td align="center">
                            <asp:Label ID="Label4" runat="server" Text="Login" Font-Bold="True" 
                                Font-Names="Verdana" ForeColor="#CC0000" Font-Size="Large"></asp:Label>
                        </td>
                        <td>
                            &nbsp;</td>
                    </tr>
                    <tr>
                        <td>
                            &nbsp;</td>
                        <td>
                            &nbsp;</td>
                        <td>
                            &nbsp;</td>
                    </tr>
                    <tr>
                        <td>
                            &nbsp;</td>
                        <td>
                            <asp:Panel runat="server" DefaultButton="SubmitBtn" ID="Panel1">
                                <table style="width:100%;">
                                    <tr>
                                        <td class="style1">
                                            <asp:Label ID="Label9" runat="server" Font-Bold="True" Font-Names="Verdana" 
                                            ForeColor="#0066FF" Text="Inupt Details:"></asp:Label>
                                        </td>
                                        <td>
                                        &nbsp;</td>
                                        <td>
                                        &nbsp;</td>
                                    </tr>
                                    <tr>
                                        <td class="style1">
                                            <asp:Label ID="Label5" runat="server" Text="Email:"></asp:Label>
                                        </td>
                                        <td>
                                            <telerik:RadTextBox ID="Email" runat="server" Skin="Default">
                                            </telerik:RadTextBox>
                                        </td>
                                        <td>
                                            <asp:CustomValidator ID="EmailValidator" runat="server" 
                                            ErrorMessage="Please Enter Email" Font-Bold="True" Font-Names="Verdana" 
                                            ForeColor="#00CC66" ControlToValidate="Email" ValidateEmptyText="True" 
                                            ValidationGroup="LoginValidation"></asp:CustomValidator>
                                        </td>
                                    </tr>
                                    <tr>
                                        <td class="style1">
                                            <asp:Label ID="Label6" runat="server" Text="Password:"></asp:Label>
                                        </td>
                                        <td>
                                            <telerik:RadTextBox ID="Password" Runat="server" Skin="Default">
                                            </telerik:RadTextBox>
                                        </td>
                                        <td>
                                            <asp:CustomValidator ID="PasswordValidator" runat="server" 
                                                ControlToValidate="Password" ErrorMessage="Please Enter Password" Font-Bold="True" 
                                                Font-Names="Verdana" ForeColor="#00CC66" ValidateEmptyText="True" 
                                                ValidationGroup="LoginValidation"></asp:CustomValidator>
                                        </td>
                                    </tr>
                                    <tr>
                                        <td class="style1" colspan="3">
                                           <hr /></td>
                                    </tr>
                                    <tr>
                                        <td class="style1">
                                            <telerik:RadButton ID="SubmitBtn" runat="server" 
                                                Skin="Default" Text="Login" ValidationGroup="LoginValidation" 
                                                Width="120px">
                                            </telerik:RadButton>
                                        </td>
                                        <td>
                                            <asp:Label ID="ResultsLabel" runat="server" ForeColor="#339933"></asp:Label>
                                        </td>
                                        <td>
                                            &nbsp;</td>
                                    </tr>
                                </table>
                            </asp:Panel>
                        </td>
                        <td>
                            &nbsp;</td>
                    </tr>
                </table>
            </td>
            <td>
                &nbsp;</td>
        </tr>
        <tr>
            <td>
                &nbsp;</td>
            <td>
                &nbsp;</td>
            <td>
                &nbsp;</td>
        </tr>
    </table>
</asp:Content>

And the .cs file:

public partial class Login : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            string email = HttpContext.Current.Request["Email"];
            Label9.Text = email;
        }
    }
}

It changes the text of Label9 to “” for some reason. First I thought the problem was in the fact that I didn’t have telerik installed, so I installed that. But it didn’t change a thing.

Answer 1

The ID of the control changes when it is being sent to the client so on PostBack the HttpContext most likely doesn’t have a field with ID "Email".

Try this:

if (IsPostBack)
{
 string email = Email.Text; //Email refers to <telerik:RadTextBox ID="Email"/>
 Label9.Text = email;
}