Call Webmethod in Usercontrol.cs from Usercontrol.ascx javascript

Question

I have a usercontrol and in that I have a javascript function which makes a call to webmethod.

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="LeftMenu.ascx.cs"
Inherits="UserControls_LeftMenu" %>

<script type="text/javascript">

function GetRealTimeCount() {
    PageMethods.CountOfMenus('', '', GetCountOfMenus_Success, GetCountOfMenus_Fail);
}

My webmethod code is

[System.Web.Services.WebMethod]
public static string CountOfMenus(string StartDate, string EndDate)
{
    //Code here
}

But when I run the code, it gives me javascript error, CountOfMenus is undefined. I know the error is because it cant find the method in the current page but I want it to access method in the usercontrol.cs. I cant write the webmethod in every page as I have lots of pages where the usercontrol is used. Is there any way through which I can call the method of usercontrol.cs in javascript?

Answer 1

I solved this by below method

Javascript :

function GetRealTimeCount(StartDate, EndDate) {
    var xmlhttp;
    if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp = new XMLHttpRequest();
    }
    else {// code for IE6, IE5
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    var url = "Default.aspx?Method=CountOfMenus&SD=" + StartDate + "&ED=" + EndDate;
    xmlhttp.open("Get", url, false);
    xmlhttp.send(null);
    document.getElementById("Count").innerHTML = xmlhttp.responseText;
}

Code Behind:

protected void Page_Load(object sender, EventArgs e)
{
    if (Request.QueryString["Method"] == "CountOfMenus")
        {
            Response.Cache.SetCacheability(HttpCacheability.NoCache);
            GetCount(Request.QueryString["SD"], Request.QueryString["ED"]);
        }
    }

    private void GetCount(string StartDate, string EndDate)
    {
        Response.Clear();

        // Code to get count

        Response.Write(Count.ToString());
        Response.End();
    }

The below link from where I got these solutions has many other options to call C# methods from javascript

http://www.morgantechspace.com/2014/01/Call-Server-Side-function-from-JavaScript-in-ASP-NET.html