Question

I am trying to make an ajax json callback using a .net application. So i make a jquery ajax call and i want the data to be sent back in json format. This is what i have done so far.

The requiest is working but the response isnt working.

JQUERY AJAX

---

function Ajax_Callback(param,callback) {

$.ajax({
    url: "default.aspx?param=" + param,
    dataType: "json",
    contentType: "application/json; charset=utf-8",
    success: function(data) {
        if (callback) {
            callback.call(null, data);
        }
    }
});

}

.NET APPLICATION for callback

---

Private Sub BaseControls_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        If Me.Page.Request.Headers.Item("X-Requested-With") = "XMLHttpRequest" Then

            Me.Page.Response.Clear()
            Me.Page.Response.ContentType = "application/json"
            Me.Page.Response.Write(Me._GetHTMLServerResponseCallback)
            Me.Page.Response.Flush()
            Me.Page.Response.End()

        End If


    End Sub

Private Sub Main_RaiseCallbackReference(ByVal pageType As BaseControls.PageEnumType, ByVal data() As String) Handles Me.RaiseCallbackReference

        Select Case pageType

            Case PageEnumType.Main


                Dim request As String = data(0)

                If request = "ThreadCreated" Then

                    Dim idThread As Integer = CInt(data(1))

                    Dim sb As New StringBuilder()
                    Dim sw As New StringWriter(sb)
                    Dim htw As New HtmlTextWriter(sw)

                    Dim userThreadControl As New UI.UserThreadControl(idThread)
                    Me.Controls.Add(userThreadControl)

                    userThreadControl.RenderControl(htw)

                    Dim html As String = sb.ToString

                    Me._GetHTMLServerResponseCallback = "[ { title: 'One', key: '1' }, { title: 'Two', key: '2' } ]"

                End If


        End Select

    End Sub

Answer 1

It was the JSON format which i was sending back in wrong format, instead of using ‘ i used “. The double quotes fixed the format and the response now occurs. Kevin B pointed out a JSON Validator, when i tested the JSON with single quotes i got errors but when using double quotes the error were no longer occurring. Thanks

Private Sub Main_RaiseCallbackReference(ByVal pageType As BaseControls.PageEnumType, ByVal data() As String) Handles Me.RaiseCallbackReference

        Select Case pageType

            Case PageEnumType.Main


                Dim request As String = data(0)

                If request = "ThreadCreated" Then

                    Dim idThread As Integer = CInt(data(1))

                    Dim sb As New StringBuilder()
                    Dim sw As New StringWriter(sb)
                    Dim htw As New HtmlTextWriter(sw)

                    Dim userThreadControl As New UI.UserThreadControl(idThread)
                    Me.Controls.Add(userThreadControl)

                    userThreadControl.RenderControl(htw)

                    Dim html As String = sb.ToString

                    Me._GetHTMLServerResponseCallback = "{ ""data"": ""<div></div>"",""threadID"": 6 }"

                End If


        End Select

    End Sub