如何将值从文本框存储到asp.net vb.net应用程序中的javascript变量中

Question

I am working with asp.net; vb.net; java script. and want to store some values in the java script variable.

<%@ Page Title="" Language="VB" MasterPageFile="~/_resx/E4.master" AutoEventWireup="true" CodeFile="new.aspx.vb" Inherits="E4_Jobs_new" ValidateRequest="false" %>

<%@ Register Src="~/_controls/ucApplicationQuestions.ascx" TagPrefix="Application"
TagName="Questions" %>

  <asp:Content ID="Content1" ContentPlaceHolderID="MainContent" runat="Server">
     <script type="text/javascript">
         var id = '<%= ModeID%>',
             mode = '<%= Mode%>',
             employer = '<%= Employer.Name %>',
             jobtitle = document.getElementById(<%= txtTitle.ClientID%>);

     </script>

     <asp:RequiredFieldValidator runat="server" ControlToValidate="txtTitle" Display="None" ErrorMessage="xx" ValidationGroup="NewJob" EnableViewState="False" />
         <div class="form-element">
              <input type="text" id="txtTitle" runat="server" maxlength="64" /></div>
</asp:Content>

Now as you can see in my code i have four java script variables.

id, mode, employer  & jobtitle

for the first 3 variable i am getting the correct result. but for the last one i am not being able to get the correct result.

what i want is the input value in the text box will be in the fourth variable (before submitting the form).

i am trying to get the value by using document.getelementbyid and store it like

jobtitle = document.getElementById(<%= txtTitle.ClientID%>)

i have also tried

jobtitle = document.getElementById(<%= txtTitle.ClientID%>).value

but its not working. (and also the editor doesnot suggest me to use value. it suggests valueof)

when i see the source code i see the following result

<script type="text/javascript">
    var id = '609',
        mode = 'draft',
    employer = 'MyPeopleBiz',
    jobtitle = document.getElementById(ctl00_MainContent_txtTitle);

</script>

and the source code for the textfield is like this

<input name="ctl00$MainContent$txtTitle" type="text" id="ctl00_MainContent_txtTitle" maxlength="64" />

how do i get the value and store the result in the javascript variable.

Answer 1

尝试这个

jobtitle = document.getElementById("<%= txtTitle.ClientID%>").value;

Answer 2

If this code is running server side, hence before the DOM is generated then you will not be able to access any DOM nodes as they will not yet exist.

Instead you could put the <%= txtTitle.ClientID%> into a hidden field on the page, and then use jQuery's $(document).ready() functionality to obtain the result of the hidden field and use it as required (ie assigning it to your global variable jobtitle .

Answer 3

Try adding a [0] before the .value:

var jobtitle = document.getElementById("<%= txtTitle.ClientID%>")[0].value;