sikha sikha - 4 years ago 90
Javascript Question

How to get javascript values on code behind in c#

I need to get javascript values on code behind in c#.I know i can use hidden field but there is no server control on page for postback.Please tell me how can get vales in code behind.

Here is my code:

<title>Facebook Get Logged in User Details UserName,Email,Profile Image</title>
<script src="jquery-1.6.2.min.js" type="text/javascript"></script>
<script type="text/javascript" src=""></script>
// Load the SDK Asynchronously

(function (d) {
var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
if (d.getElementById(id)) { return; }
js = d.createElement('script'); = id; js.async = true;
js.src = "//";
ref.parentNode.insertBefore(js, ref);
} (document));

// Init the SDK upon load
window.fbAsyncInit = function () {
appId: 'APPID', // App ID
channelUrl: '//' + window.location.hostname + '/channel', // Path to your Channel File
status: true, // check login status
cookie: true, // enable cookies to allow the server to access the session
xfbml: true // parse XFBML

// listen for and handle auth.statusChange events
FB.Event.subscribe('auth.statusChange', function (response) {
if (response.authResponse) {
// user has auth'd your app and is logged into Facebook
var uid = "" + response.authResponse.userID + "/picture";
FB.api('/me', function (me) {
document.getElementById('auth-displayname').innerHTML =;
document.getElementById('myJSString').value =;


document.getElementById('Email').innerHTML =;
document.getElementById('profileImg').src = uid;

// document.getElementById('ctl00_CPHDefault_tcTPS_TPProd_ctl01_tcProduction_TPNewT‌​itlesStatus_ChangedRowsIndicesHiddenField').value = uid;
// alert('yyy');

document.getElementById('auth-loggedout').style.display = 'none';
document.getElementById('auth-loggedin').style.display = 'block';
} else {
// user has not auth'd your app, or is not logged into Facebook
document.getElementById('auth-loggedout').style.display = 'block';
document.getElementById('auth-loggedin').style.display = 'none';
$("#auth-logoutlink").click(function () { FB.logout(function () { window.location.reload(); }); });

Facebook Login Authentication Example</h1>
<div id="auth-status">
<div id="auth-loggedout">
<div id="Result" class="fb-login-button" autologoutlink="true" scope="email,user_checkins">Login</div>
<div id="auth-loggedin" style="display: none">
Name: <b><span id="auth-displayname"></span></b>(<a href="#" id="auth-logoutlink">logout</a>)<br />
Email: <b><span id="Email"></span></b><br />
Profile Image: <img id="profileImg" />

<form runat="server">
<asp:HiddenField runat="server" id="myJSString" />


You can see there is no server control so how i can get NAME,UID variables in code behind.


Answer Source

I would investigate the use of ASP.NET AJAX Page Methods, because they allow for script callable stand-alone web services that live in an .aspx page, like this:

Page Method in your code-behind file (call it default.aspx for discussion's sake):

public static string SaveData(string name, string uid)
    // Logic here to do what you want with name and uid values (i.e. save to database, call another service, etc.)

jQuery call to default.aspx's SaveData method:

    type: "POST",
    url: "default.aspx/SaveData",
    data: "{'name':'John', 'uid':'ABC123'}",
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function(msg) {
        // Do something interesting here.

Notes: ASP.NET AJAX Page Methods automatically encode their response to JSON so you will not see any JSON serialization in the code-behind or any serialization logic at all.

For more information about ASP.NET AJAX Page Methods check out Using jQuery to directly call ASP.NET AJAX page methods

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