Ajax不进行函数调用

Question

I have ajax function as:

function LoadTeacherObservationData(_CategoryID, _SearchText) {
        alert("In here");
        alert(_CategoryID);
        alert(_SearchText);
        flag = 1;
        $.ajax({
            url: "PP/getTeacherObservationData",
        data: {
        'CategoryID': _CategoryID,
        'SearchText': _SearchText
        },
    dataType: "json",
        type: 'POST',
    cache:false,
    success: function (data) {
        OnlebelChange(_CategoryID);
        $('#hdnCategoryID').val(_CategoryID);

        $("#lvTeacherData").kendoListView({
            dataSource: data,
            dataBound: function(e) {
                if(this.dataSource.data().length == 0){
                    //custom logic
                    $("#lvTeacherData").append("<h4>&nbsp;&nbsp;No record found.</h4>");

                }},
            template: kendo.template($("#lvTeacherData_Template").html())
        });
    },
    error: function () {
        alert("error in click");
    }
    });
    }

I have made sure that function is getting called with correct parameters as i have checked it through alert box.

My problem is its not getting rendered to:

PP/getTeacherObservationData as i have mentioned in URL.

PP is my controller and getTeacherObservationData is my function.

I have written that function as follows:

public JsonResult getTeacherObservationData(string CategoryID, string SearchText)
        {
            try
            {
                if (CategoryID == "1")
                    return Json(new TeacherObservation().ScheduledObserVations(SearchText));
                if (CategoryID == "2")
                    return Json(new TeacherObservation().InProcessObservations(SearchText));
                if (CategoryID == "3")
                   return Json(new TeacherObservation().CompletedObservations(SearchText));

                return Json(new List<TeacherObservation>());
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

Instead of calling this function ajax function code goes in error block and gives me alert as: error in click

What can be the problem??

Please help me.

I want to make function call through ajax.

Using MVC4.

Answer 1

I don't know what PHP Framework you are using, but normally you can't just return a value to an AJAX call, you have to ouput it somehow to send it back to the caller. Try to use echo or print instead of return.

To prevent further rendering (if any), you should somehow end the script after it has echoed your specified JSON.

You should also check for the output that is rendered in firebug or similar consoles to see if you get a plain JSON (which you obvoiously expect) or some HTML wrapped content which is rendered by your php framework and connot be parsed.