How to call function in C# from javascript at particular time

Question

<script type="text/javascript">
   var startTime = new Date();
   var TimeTaken;
        //Start the clock!
   window.onbeforeunload = function ()        
   {
       var endTime = new Date();
       //Get the current time.
       var timeSpent = (endTime - startTime);
       seconds = (timeSpent / 1000) % 60;
       TimeTaken = parseInt(seconds);
       //return TimeTaken;
       var temp = document.getElementById('<%=Label1.ClientID %>').value;
       temp = TimeTaken;
       alert(temp);
         <%PageO(); %>
  };

The above JS file runs when I close the tab/page in browser. But the function Which I called <%PageO(); %> executes when the programs starts running itself. This function call in code behind(C#) should execute only when the tab/page is closed not at the start of the program.

Any mistakes in this code?

use ajax jquery call see this links http://www.c-sharpcorner.com/UploadFile/8911c4/how-to-call-C-Sharp-methodfunction-using-jquery-ajax/ and http://www.c-sharpcorner.com/UploadFile/dacca2/understand-jquery-ajax-function-call-code-behind-C-Sharp-method/ — Frebin Francis, Feb 27 '15 at 06:46
i already posted some links, are you using ASP.net web forms ? — Frebin Francis, Feb 27 '15 at 06:47

score 1 · Accepted Answer · answered Feb 27 '15 at 06:51

1

Try This - You have to use PageMethods

<script type="text/javascript">
var startTime = new Date();
   var TimeTaken;
        //Start the clock!
   window.onbeforeunload = function ()        
   {
       var endTime = new Date();
       //Get the current time.
       var timeSpent = (endTime - startTime);
       seconds = (timeSpent / 1000) % 60;
       TimeTaken = parseInt(seconds);
       //return TimeTaken;
       var temp = document.getElementById('<%=Label1.ClientID %>').value;
       temp = TimeTaken;
       alert(temp);
       // USE PAGEMETHODS FOR CODE BEHIND METHOD CALL
         PageMethods.PageO(function (response) {                 
        alert(response);
    });
  };
</script>

And you have to add ScriptManager in your .aspx page as below

<asp:ScriptManager ID="ScriptManager1" runat="server" EnablePageMethods="true">

And in .aspx.cs file your Method with WebMethod as below

`

[System.Web.Services.WebMethod]
```
public static string PageO()
     {
        return "Yes this is working";
     }
```
`

answered Feb 27 '15 at 06:51

prog1011

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@SRIRAMRAMACHANDRAN - Use PageMethod as above code example. – prog1011 Feb 27 '15 at 06:55
yeah thanks ... the function is called when I close the tab ... but I need to pass the temp value to C# function also ... so only I just moved the value to Label1.. But if i use public static ... I cannot access the controls .. – SRIRAM RAMACHANDRAN Feb 27 '15 at 07:02
I would not recommend using asp.net ajax (formerly known as atlas) / webmethods, because these are outdated technologies, and while they are still supported it's a dead-end, especially given that better alternatives are readily available. – Andrew Savinykh Feb 27 '15 at 07:03
I'm not saying it didn't. I'm saying you are better off not using it, because it is not a good solution. – Andrew Savinykh Feb 27 '15 at 07:06
@zespri - the alternate option for PageMethod is `ajax call` - you can use `ajax call` also. – prog1011 Feb 27 '15 at 07:07
@SRIRAMRAMACHANDRAN - if you want to pass `label` value to your static method. You can paas that value like `PageMethods.PageO('label value')` and change your c# function like `public static string PageO(string value){}` – prog1011 Feb 27 '15 at 07:08

How to call function in C# from javascript at particular time

1 Answers1