The ASP.net PageMethods are returning an undefined value

Question

The ASP.net PageMethods are returning an undefined value

Hello everyone, I am attempting to retrieve data from C# to JavaScript using ToolkitScriptManager. Here is my ASPX code:

    <html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="../assets/lib/jquery/jquery-2.0.3.js" type="text/javascript"></script>

    <script>
        $(window).load(function () {
            alert(PageMethods.isConnected());
        });
    </script>
</head>
<body>
    <form id="form1" runat="server">
        <asp:ToolkitScriptManager runat="Server"
            EnablePageMethods="true"
            EnablePartialRendering="true" />
    <div>

    </div>
    </form>
</body>
</html>

And here is my code behind:

[ScriptMethod, WebMethod]
        public static bool isConnected()
        {
            return true;
        }

I'm not sure why the result keeps coming back as undefined. Apologies if this seems like a simple issue for you, but as someone new to ASP.NET, I find it challenging. Could someone please assist me in resolving this problem?

javascript asp.net asp.net-ajax computer-science pagemethods

Answer 1

Answer №1

Ensure to provide both a success callback and a failure callback when making a call to the webmethod, as demonstrated below.

  $(window).load(function () {
                                    PageMethods.isConnected(fnsuccesscallback, fnerrorcallback);

        });
        function fnsuccesscallback(data) {
            alert(data);

        }
        function fnerrorcallback(result) {
            alert(result.statusText);
        }

Alternatively, you can access the page methods using $.ajax in another way.

<head id="Head1" runat="server">
    <title></title>
    <script src="../assets/lib/jquery/jquery-2.0.3.js" type="text/javascript"></script>
    <script src="Scripts/jquery-1.9.1.js" type="text/javascript"></script>
    <script type="text/javascript" language="javascript">

         $(window).load(function () {

      $.ajax({
            type: "POST",
            url: "PageMethodTest.aspx/isConnected",
            data: "{}",
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: fnsuccesscallback,
            error: fnerrorcallback
        });
    });            function fnsuccesscallback(data) {
            alert(data.d);

        }
        function fnerrorcallback(result) {
            alert(result.statusText);
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <asp:ScriptManager EnablePageMethods="true" runat="server">
    </asp:ScriptManager>
    <div>
    </div>
    </form>
</body>

Answer 2

Ensure to provide both a success callback and a failure callback when making a call to the webmethod, as demonstrated below.

  $(window).load(function () {
                                    PageMethods.isConnected(fnsuccesscallback, fnerrorcallback);

        });
        function fnsuccesscallback(data) {
            alert(data);

        }
        function fnerrorcallback(result) {
            alert(result.statusText);
        }

Alternatively, you can access the page methods using $.ajax in another way.

<head id="Head1" runat="server">
    <title></title>
    <script src="../assets/lib/jquery/jquery-2.0.3.js" type="text/javascript"></script>
    <script src="Scripts/jquery-1.9.1.js" type="text/javascript"></script>
    <script type="text/javascript" language="javascript">

         $(window).load(function () {

      $.ajax({
            type: "POST",
            url: "PageMethodTest.aspx/isConnected",
            data: "{}",
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: fnsuccesscallback,
            error: fnerrorcallback
        });
    });            function fnsuccesscallback(data) {
            alert(data.d);

        }
        function fnerrorcallback(result) {
            alert(result.statusText);
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <asp:ScriptManager EnablePageMethods="true" runat="server">
    </asp:ScriptManager>
    <div>
    </div>
    </form>
</body>

Answer 3

Answer №2

Guaranteed to deliver results

     <script type="text/javascript>
       function StartProcess()
       {              
           var result = PageMethods.Initiate(your parameter, function (response)
           {
               alert(response);
           });
       }
</script>

Answer 4

Guaranteed to deliver results

     <script type="text/javascript>
       function StartProcess()
       {              
           var result = PageMethods.Initiate(your parameter, function (response)
           {
               alert(response);
           });
       }
</script>

The ASP.net PageMethods are returning an undefined value

Answer №1

Answer №2

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