jquery Ajax call - data parameters are not being passed to MVC Controller action

Question

I\'m passing two string parameters from a jQuery ajax call to an MVC controller method, expecting a json response back. I can see that the parameters are populated on the cl

Answer 1

You need add -> contentType: "application/json; charset=utf-8",

<script type="text/javascript">
    $(document).ready( function() {
      $('#btnTest').click( function() {
        $.ajax({
          type: "POST", 
          url: "/Login/Test",
          data: { ListID: '1', ItemName: 'test' },
          dataType: "json",
          contentType: "application/json; charset=utf-8",
          success: function(response) { alert(response); },
          error: function(xhr, ajaxOptions, thrownError) { alert(xhr.responseText); }
        });
      });
    });
</script>

Answer 2

In my case, if I remove the the contentType, I get the Internal Server Error.

This is what I got working after multiple attempts:

var request =  $.ajax({
    type: 'POST',
    url: '/ControllerName/ActionName' ,
    contentType: 'application/json; charset=utf-8',
    data: JSON.stringify({ projId: 1, userId:1 }), //hard-coded value used for simplicity
    dataType: 'json'
});

request.done(function(msg) {
    alert(msg);
});

request.fail(function (jqXHR, textStatus, errorThrown) {
    alert("Request failed: " + jqXHR.responseStart +"-" + textStatus + "-" + errorThrown);
});

And this is the controller code:

public JsonResult ActionName(int projId, int userId)
{
    var obj = new ClassName();

    var result = obj.MethodName(projId, userId); // variable used for readability
    return Json(result, JsonRequestBehavior.AllowGet);
}

Please note, the case of ASP.NET is little different, we have to apply JSON.stringify() to the data as mentioned in the update of this answer.

Answer 3

I tried:

<input id="btnTest" type="button" value="button" />

<script type="text/javascript">
    $(document).ready( function() {
      $('#btnTest').click( function() {
        $.ajax({
          type: "POST", 
          url: "/Login/Test",
          data: { ListID: '1', ItemName: 'test' },
          dataType: "json",
          success: function(response) { alert(response); },
          error: function(xhr, ajaxOptions, thrownError) { alert(xhr.responseText); }
        });
      });
    });
</script>

and C#:

[HttpPost]
public ActionResult Test(string ListID, string ItemName)
{
    return Content(ListID + " " + ItemName);
}

It worked. Remove contentType and set data without double quotes.

Answer 4

If you have trouble with caching ajax you can turn it off:

$.ajaxSetup({cache: false});

Answer 5

  var json = {"ListID" : "1", "ItemName":"test"};
    $.ajax({
            url: url,
            type: 'POST',        
            data: username, 
            cache:false,
            beforeSend: function(xhr) {  
                xhr.setRequestHeader("Accept", "application/json");  
                xhr.setRequestHeader("Content-Type", "application/json");  
            },       
            success:function(response){
             console.log("Success")
            },
              error : function(xhr, status, error) {
            console.log("error")
            }
);