"Unknown Web Method" Ajax Error

Question

The data being return in the error function is saying: Unknown web method IncrementTable(pageNumber). Parameter name: methodName. I'm sure that I've made a small mistake somewhere, but hoping a second pair of eyes can help me find it. :)

My .aspx page looks like this:

<%@ Page Title="TouchStoneTV" Language="VB" AspCompat="True" AutoEventWireup="True" Debug="True" EnableEventValidation="True" ValidateRequest="False" Trace="False" EnableViewState="True" %>

<%@ Import Namespace="System.Web.Services" %>
<%@ Import Namespace="System.Web.Script.Services" %>

<WebMethod()> _
Public Shared Function IncrementTable '(ByVal PageNumber As Integer)

Dim PageNumber As Integer = 1
For x As Integer = 0 To Math.Ceiling(RowsPerPage/CellsPerRow)

    Dim r As TableRow = New TableRow
    'If (x Mod CellsPerRow) = 0 Then r = New TableRow
    r.Attributes.Add("style","text-align:center;height:200px;width:50%;")

    Dim c1, c2 As New TableCell
    c1.Attributes.Add("style","border:1px solid #000;")
    c2.Attributes.Add("style","border:1px solid #000;")
    c1.Controls.Add(New LiteralControl(PageNumber.ToString & "a : " & x.ToString))
    c2.Controls.Add(New LiteralControl(PageNumber.ToString & "b : " & x.ToString))
    r.Cells.Add(c1)
    r.Cells.Add(c2)

    MainContentTable.Rows.Add(r)

Next x

Return "test"

End Function

And the javascript look like this:

<script src="http://code.jquery.com/jquery-1.10.1.min.js"></script>
<script type="text/javascript">

var pageNumber = 1;
//var webMethodUrl = '<%=ResolveUrl("~/Mobile.aspx/IncrementTable(pageNumber)") %>'; //alert(webMethodUrl); //this gets a 404-not found error
var webMethodUrl = 'Mobile.aspx/IncrementTable(pageNumber)'; 

$(document).ready(function () {
    $(window).scroll(function () {
        // Get the current vertical position of the scrollbar.  If it's equal to the height of the document minus the 
        // window height then go get some more data
        if ($(window).scrollTop() == $(document).height() - $(window).height()) {
            // Increment page number and set up the parameters
            pageNumber += 1;
            var params = "{'pageNumber': " + pageNumber + "}";

            // Async post back to the BindDataAsync code behind web method
            $.ajax({
                type: "POST",
                url: webMethodUrl,
                data: params,
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                error: function (data) {alert('error: ' + data);},
                success: function (data) {alert('success');
                    //if (data != "") {
                        // Take the results from the web service method and append them to the table
                    //    $('#ProductsTable').append(data.d);
                    //}
                }
            });
        }
    });
});

</script>

Answer 1

The method is configured for invocation using httpget but you are using POST method to invoke in javascript.

<WebMethod()> _
<ScriptMethod(UseHttpGet:=True, ResponseFormat:=ResponseFormat.Json)> _
Public Shared Sub IncrementTable(ByVal PageNumber As Integer)
  'code
End Sub

Just remove UseHttpGet:=True and it should fix your issue. Or change jquery ajax code to use GET request and pass parameter as querystring