Question

I’m pretty new to asp.net and MVC.

I was trying to use json request and populate some text boxes.

but I noticed when I’m using json, I can not access values of the other text boxes in my view.
for example

string s2 = Request.Form["selectedTestCategory"];

would generate s2 = null, when I debug.
but if I put a submit button on the page, the value is not null. (And so far I know I can only pass one parameter to my JSON method in controller)

My question is what happens when I start a json request? and why I can not get a value from Request.Form[…]

Thanks,

Update:

This is my json

<script>
$(document).ready(function() {
    $('select#testStationUniqueId').change(function() {
        var testStation = $(this).val();
        $.ajaxSetup({ cache: false });



        $.ajax({
            url: "TestInput/getTestStationInformation/" + testStation,

            type: 'post',
            success: function(data) {
                $('#driveDetailDiv').empty();
                for (var i = 0; i < data.length; i++) {
                    $.post('TestInput/Details/', { id: data[i] }, function(data2) {
                        $('#driveDetailDiv').append(data2);
                    });
                }
            }
        });
    });
});

And this is in my controller

public PartialViewResult Details(string id)
    {
        //DriveDetails t = new DriveDetails(id);
        //return PartialView("DriveDetailsPartial", t);

        test_instance_input_model ti = new test_instance_input_model();
        string s2 = Request.Form["selectedTestCategory"];
        repository.setTestInstanceAttributes(ti, id);

        return PartialView("TestInstancePartial", ti);
    }

the s2 is null in Details, but if I use a submit button, it will have the correct value.

so I’m trying to figure out why it is null when I send a json request.

Answer 1

In your JavaScript your not including any data in the jQuery ajax request (see jQuery ajax). Therefore jQuery isn’t adding any request parameters. You need to include a data object which jQuery will turn into parameters i.e. the more properties in the data object the more parameters in the request.

$.ajax({
    url: '',
    data: { selectedTestCategory: 'category' },
    dataType: 'post',
    success: function() {}
});

Also, in your controller you can shortcut to the request parameter.

string s2 = Request["selectedTestCategory"];