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Strange anamoly in ASP.NET Web Forms (code not working with no errors ...)

I'm facing a strange anomaly in C# (ASP.NET Web Forms).
I have an ascx Web Page where I call a function creating a JSON from localStorage values.
function creerJsonDepuisLocalStorage() {
var modif = {}
// Filling modif with localStorage values ...
try {
return JSON.stringify(modifs);
} catch (e) {
console.log(e);
return "";
}
}
My codebehind is called on submit button click and recover the JSON to use it.
protected void btnEnregistrerFiche_OnClick(object sender, EventArgs e)
{
// tons of code ... doing various things like !!DataBase access!!
string argument = Request.Form["__EVENTARGUMENT"];
JavaScriptSerializer ser = new JavaScriptSerializer();
try
{
FicheModifiee edits = ser.Deserialize<FicheModifiee>(argument);
// edits treatments, commented for debug
}
catch(Exception ex)
{
Console.WriteLine(ex.Message);
}
// some other code like !!UI update!!
}
My problem is the following :
When my front end javascript function returns an empty string, the codebehind function works like a charm, doing database modifications and updating UI.
When my front end javascript function returns a real object, the codebehind function is correctly deserializing the JSON into the edits class and I don't have any bug or crashes BUT database access isn't made and UI is updating with previous data (not considering any changes made before submitting).
This sounds like dark magic as I'm not getting any crashes and my little piece of code isn't doing anything with the rest of the function ...
Thanks for your help.

I managed to fix my problem by using an asp:hiddentField (set at the end of my json creation script) and by reading it directly from C# code. Still not knowing what happend with Request.Form["__EVENTARGUMENT"];

Get data from JS variable and set in a ASP.NET variable

I want to pass data from one user control to another one, but i've tried several things to do it, and non of them worked, such as sessionStorage in JS, Session in ASPX, cookies in both of them.
This data is dynamic so I don't now how to transfer it, to the other user control.
I even tried to put aspx code in the javascript function (then when I click in the button it could trigger the code, but it doesn't work as well).
This button i refereed above is written in a literal control.
JavaScript Functions
this function is the LoadUsers UserControl
function getID(ID) {
sessionStorage.setItem("userID", ID);
}
this function is in the Access UserControl
function catchIP() {
var ID = sessionStorage.getItem("userID");
$('#<%= value.ClientID %>').val(ID);
}
UserControls
Load Users:
...
string _str = "<a href'#lastAccess' css='btn btn-success' onclick='javascript:getID(" + _id[_contForeach] + "); catchID();'>Access</a>";
_loadUsers.Controls.Add(new LiteralControl(_str));
Access:
How can I get access to the ID in the JavaScript function and apply it without using Page_Load

To pass information between the server side code and the client side code (JavaScript) use ajax
Ajax
So using jquery, have something like this function:
$.get('getuserid.aspx', function(response) {
//Do something with return response
});
then in the code behind getuserid.aspx.cs
private void Page_Load(object sender, System.EventArgs e)
{
Response.Expires = -1;
//required to keep the page from being cached on the client's browser
//set userid
Response.ContentType = "text/plain";
Response.Write(userid);
Response.End();
}

JavaScript: Multiple parameters in __doPostBack

First of all, the only post (calling-multiple-dopostback-from-javascript) I found about this didn't help my problem, so I don't belive this post is a duplicate.
I have this JavaScript function in my ASPX webpage that includes a __doPostBack function:
function OpenSubTable(bolID, controlID) {
// code
__doPostBack('UpdatePanelSearch', bolID);
// more code
}
Works perfectly and I can get the value of bolID into my code behind like this:
protected void UpdatePanelSearch_Load(object sender, EventArgs e)
{
var bolID = Request["__EVENTARGUMENT"];
// code
}
The problem is, that I have to pass 2 different values through the postback. Are there any simple solutions to this? Obviously something like this doesn't work:
function OpenSubTable(bolID, controlID) {
// code
__doPostBack('UpdatePanelSearch', bolID, controlID); // not that simple, i'm afraid :(
// more code
}
Any help would be most welcome.
Regards,
Gunnar

You could pass the two values as one JSON string:
function OpenSubTable(bolID, controlID) {
__doPostBack('UpdatePanelSearch', JSON.stringify({ bolID: bolID, controlID: controlID}));
}
And then parse it on the server:
protected void UpdatePanelSearch_Load(object sender, EventArgs e)
{
SomeDTO deserializedArgs =
JsonConvert.DeserializeObject<SomeDTO>(Request["__EVENTARGUMENT"]);
var bolID = deserializedArgs.bolID;
var controlID = deserializedArgs.controlID;
}
public class SomeDTO
{
public string bolID { get; set; }
public string controlID { get; set; }
}
If you're using .Net >=4.0, I believe you can deserialize to a generic touple and avoid having to create SomeDTO. Edit: More information about deserializing to dynamic types.

Consider placing your data in server side hidden fields and then reading that data after your postback.
<asp:HiddenField id="Data1HiddenField" runat="server" />
<asp:HiddenField id="Data2HiddenField" runat="server" />
Your client script should include the ClientID values to handle server side naming container modifications. Using the <%= expression %> syntax (Expression Builder) requires that your script (or at least this part of the script) be maintain within your .aspx file. If you maintain your JavaScript in external files, you can "register" a simple function that gets called by your main JavaScript to move the data and compose that function server side along with the required ClientIDs. See ClientScriptManager.RegisterClientScriptBlock().
var data1 = "data value 1";
var data2 = "data value 2";
$("#<%= Data1HiddenField.ClientID %>").val(data1);
$("#<%= Data2HiddenField.ClientID %>").val(data2);
Your server side code then looks like this:
string data1 = Data1HiddenField.Value;
string data2 = Data2HiddenField.Value;
There are certainly other techniques to passing multiple data values but I have found this to be both simple and easy to maintain. You can pass all kinds of data and encode it using JSON if needed.

I have used multiple parameters before by building and splitting a string.
eg
string args = String.Format("{0};{1}", bolID, ControlID);
You can then pass this in to the arguments for the postback, and when checking for the postback arguments just split the string based on your speration character (in this case ';')

value from javascript is not returning to c# in the application in Visual Web GUI

I have written a java script function in the skin file of the visual web Gui application which returns some value too. Now i am invoking the java script method from code behind.
public void XYZ( string message)
{
this.InvokeMethodWithId("testCall", message);
}
And javascript function is:--
function testCall(strGuid, txt) {
alert("hai Java script fired..");
return txt+ 'returned from JavaScript';
}
I want the value returned from JavaScript in the application. how can i achieve it. Is there in other method to invoke the methods of JavaScript?
I want something like this:--
public void Conect( string message)
{
string returnedvalue = this.InvokeMethodWithId("testCall", message);
}

Javascript is executed on the client so the return won't make it to the server.
A solution could be to use AJAX to send that value to the server. Stack Overflow is full of answers about AJAX.
Here's a good example.

#Amish Kumar,
As noted by other replies already, the client-side and server-side are not directly connected in web programming. The client is always the initiator of every request, and the server-side's "purpose" is to render a response, which will then be returned to the client for processing, in Visual WebGui this is usually some UI update processing. This basically means that your client script will not execute until the server-side has finished rendering the response, and the only way the client can get some message back to the server is to issue another request.
Think about how you need to use the MessageBox in Visual WebGui for instance. In order to receive the "response" from the MessageBox, you need to supply a callback handler in your server-side code, and then your server-side code will have completed creating the response, which is returned to the client. The client updates its UI and on some action to the MessageBox dialog, it sends a new request to the server, which interpretes the action and invokes your callback handler. In the callback handler you use Form.DialogResult to get the user action.
A very basic way to make this work in custom Visual WebGui code could be like the following code on a Form:
private void button1_Click(object sender, EventArgs e)
{
SendClientMessage("This is a test");
}
public void SendClientMessage(string strMessage)
{
System.Text.StringBuilder sb = new StringBuilder();
sb.AppendLine("var objEvent = mobjApp.Events_CreateEvent('{0}', 'MessageEvent');");
sb.AppendLine("mobjApp.Events_SetEventAttribute(objEvent, 'Msg', '{1}');");
sb.AppendLine("mobjApp.Events_RaiseEvents();");
this.InvokeScript(string.Format(sb.ToString(), this.ID, strMessage));
}
protected override void FireEvent(Gizmox.WebGUI.Common.Interfaces.IEvent objEvent)
{
if (objEvent.Type == "MessageEvent")
MessageBox.Show(objEvent["Msg"]);
else
base.FireEvent(objEvent);
}
This code will not work unless you set your Visual WebGui applicaton for no Obscuring. In order for this code to work on an obscured application, you would need to add the JavaScript as an obscured JavaScript resource and it would work fine.
Palli
enter code here

how to access javascript querystring in codebehind?

im sending a value from one page in aspx to another page as shown below.
window.location="test1.aspx?id=1"
how to access this value in codebehind or global.asax?

You could retrieve the id parameter from the Request object in your code behind:
protected void Page_Load(object sender, EventArgs e)
{
string id = Request["id"];
// do something with the id
}
Also you will have to fix your javascript because the url you are assigning is invalid. You have an extra + character that should be removed:
window.location.href = 'test1.aspx?id=1';

Leave the + sign out and use the Request.QueryString object.
window.location="test1.aspx?id=1"
string v = Request.QueryString["id"];