I have a function that triggers on a button click that passes the following argument: insertSongPlay(newSong.songID); when I console.log the newSong.songID I see a value of 90, which is desired.
This function is called here which runs an ajax call:
function insertSongPlay(songID)
{
$.ajax
({
type: "POST",
contentType: "application/json; charset=utf-8",
dataType: "json",
url: "/Album/InsertSongPlay/",
data: JSON.stringify({ "songID": songID }),
success: function(data)
{
console.log("submitted");
console.log(songID);
//TODO: Indicate Success
},
error: function(jqXHR, textStatus, errorThrown)
{
//TODO: Indicate Error
console.log(errorThrown);
}
});
}
Here is the corresponding ajax url found in my AlbumController:
public JsonResult InsertSongPlay(int songID)
{
try
{
EntityDataAccess.InsertSongPlay(songID);
return Json(true);
}
catch(Exception ex)
{
return Json(ex);
}
}
Then in my EntityDataAccess.cs the following is run from the InsertSongPlay entity data access:
public static SongPlayDaily InsertSongPlay(int songID)
{
using(var Context = GetContext())
{
var currentSongPlay = Context.SongPlayDailies.FirstOrDefault(x => x.SongID == songID && x.PlayDate == DateTime.Now.Date);
if (currentSongPlay != null)
currentSongPlay.NumberOfPlays++;
else
{
currentSongPlay = new SongPlayDaily();
currentSongPlay.SongID = songID;
currentSongPlay.PlayDate = DateTime.Now.Date;
currentSongPlay.NumberOfPlays = 1;
Context.SongPlayDailies.Add(currentSongPlay);
}
Context.SaveChanges();
return currentSongPlay;
}
}
However, my ajax call always throws an error and prints Internal Server Error to the console log. The Visual Studio debug mode indicates some sort of circular reference error. I'm not quite sure where I'm going wrong.
Thanks!
As we figured out in comments - there are multiple problems here. First,
return Json(ex);
Is a bad idea. That will inspect all properties of exception and try to serialize them, and all properties of those properties, to json. As you see, that is not going well, and also completely unnecessary. If you want to return error response to client - prepare it (use ex.Message for example). Plus, you don't want to return sensetive information (like stack trace) to your clients on every error.
Besides that - by doing return Json() on exception - you violate HTTP conventions. Json() will return response with status code 200 OK. But in your case it's not really "ok" - so you should return another status code indicating error. If not that circular reference error - your code in ajax "error" handler would never has been triggered, even when there was really an error.
Easiest way to fix it is just remove try-catch completely and let framework handle that for you.
Second problem is
x.PlayDate == DateTime.Now.Date
filter in query. Entity Framework has problem with accessing Date property of DateTime objects and refuses to convert that into SQL query. You can either move that to another variable:
var today = DateTime.Now.Date;
Where(x => x.PlayDate == today)
or use DbFunctions.TruncateTime:
Where(x => x.PlayDate == DbFunctions.TruncateTime(DateTime.Now))
Note that those ways are not exactly equivalent. First will compare with exact date value, and second will use SQL SYSDATETIME() function. In this case that hardly matters though.
Is it because you're missing the [HttpPost] attribute over your controller action?
[HttpPost]
public JsonResult InsertSongPlay(int songID)
{
try
{
EntityDataAccess.InsertSongPlay(songID);
return Json(true);
}
catch(Exception ex)
{
return Json(ex);
}
}
in post action you should use complex type for receive data from client.
try this
[HttpPost]
public JsonResult InsertSongPlay(SongModel songModel)
{
try
{
EntityDataAccess.InsertSongPlay(songModel.songID);
return Json(true);
}
catch(Exception ex)
{
return Json(ex);
}
}
public class SongModel{
public int songID {get;set}
}
Related
I am trying to create controller actions which will return either JSON or partial html depending upon a parameter. What is the best way to get the result returned to an MVC page asynchronously?
In your action method, return Json(object) to return JSON to your page.
public ActionResult SomeActionMethod() {
return Json(new {foo="bar", baz="Blech"});
}
Then just call the action method using Ajax. You could use one of the helper methods from the ViewPage such as
<%= Ajax.ActionLink("SomeActionMethod", new AjaxOptions {OnSuccess="somemethod"}) %>
SomeMethod would be a javascript method that then evaluates the Json object returned.
If you want to return a plain string, you can just use the ContentResult:
public ActionResult SomeActionMethod() {
return Content("hello world!");
}
ContentResult by default returns a text/plain as its contentType.
This is overloadable so you can also do:
return Content("<xml>This is poorly formatted xml.</xml>", "text/xml");
I think you should consider the AcceptTypes of the request. I am using it in my current project to return the correct content type as follows.
Your action on the controller can test it as on the request object
if (Request.AcceptTypes.Contains("text/html")) {
return View();
}
else if (Request.AcceptTypes.Contains("application/json"))
{
return Json( new { id=1, value="new" } );
}
else if (Request.AcceptTypes.Contains("application/xml") ||
Request.AcceptTypes.Contains("text/xml"))
{
//
}
You can then implement the aspx of the view to cater for the partial xhtml response case.
Then in jQuery you can fetch it passing the type parameter as json:
$.get(url, null, function(data, textStatus) {
console.log('got %o with status %s', data, textStatus);
}, "json"); // or xml, html, script, json, jsonp or text
Another nice way to deal with JSON data is using the JQuery getJSON function. You can call the
public ActionResult SomeActionMethod(int id)
{
return Json(new {foo="bar", baz="Blech"});
}
Method from the jquery getJSON method by simply...
$.getJSON("../SomeActionMethod", { id: someId },
function(data) {
alert(data.foo);
alert(data.baz);
}
);
I found a couple of issues implementing MVC ajax GET calls with JQuery that caused me headaches so sharing solutions here.
Make sure to include the data type "json" in the ajax call. This will automatically parse the returned JSON object for you (given the server returns valid json).
Include the JsonRequestBehavior.AllowGet; without this MVC was returning a HTTP 500 error (with dataType: json specified on the client).
Add cache: false to the $.ajax call, otherwise you will ultimately get HTTP 304 responses (instead of HTTP 200 responses) and the server will not process your request.
Finally, the json is case sensitive, so the casing of the elements needs to match on the server side and client side.
Sample JQuery:
$.ajax({
type: 'get',
dataType: 'json',
cache: false,
url: '/MyController/MyMethod',
data: { keyid: 1, newval: 10 },
success: function (response, textStatus, jqXHR) {
alert(parseInt(response.oldval) + ' changed to ' + newval);
},
error: function(jqXHR, textStatus, errorThrown) {
alert('Error - ' + errorThrown);
}
});
Sample MVC code:
[HttpGet]
public ActionResult MyMethod(int keyid, int newval)
{
var oldval = 0;
using (var db = new MyContext())
{
var dbRecord = db.MyTable.Where(t => t.keyid == keyid).FirstOrDefault();
if (dbRecord != null)
{
oldval = dbRecord.TheValue;
dbRecord.TheValue = newval;
db.SaveChanges();
}
}
return Json(new { success = true, oldval = oldval},
JsonRequestBehavior.AllowGet);
}
To answer the other half of the question, you can call:
return PartialView("viewname");
when you want to return partial HTML. You'll just have to find some way to decide whether the request wants JSON or HTML, perhaps based on a URL part/parameter.
Alternative solution with incoding framework
Action return json
Controller
[HttpGet]
public ActionResult SomeActionMethod()
{
return IncJson(new SomeVm(){Id = 1,Name ="Inc"});
}
Razor page
#using (var template = Html.Incoding().ScriptTemplate<SomeVm>("tmplId"))
{
using (var each = template.ForEach())
{
<span> Id: #each.For(r=>r.Id) Name: #each.For(r=>r.Name)</span>
}
}
#(Html.When(JqueryBind.InitIncoding)
.Do()
.AjaxGet(Url.Action("SomeActionMethod","SomeContoller"))
.OnSuccess(dsl => dsl.Self().Core()
.Insert
.WithTemplate(Selector.Jquery.Id("tmplId"))
.Html())
.AsHtmlAttributes()
.ToDiv())
Action return html
Controller
[HttpGet]
public ActionResult SomeActionMethod()
{
return IncView();
}
Razor page
#(Html.When(JqueryBind.InitIncoding)
.Do()
.AjaxGet(Url.Action("SomeActionMethod","SomeContoller"))
.OnSuccess(dsl => dsl.Self().Core().Insert.Html())
.AsHtmlAttributes()
.ToDiv())
You may want to take a look at this very helpful article which covers this very nicely!
Just thought it might help people searching for a good solution to this problem.
http://weblogs.asp.net/rashid/archive/2009/04/15/adaptive-rendering-in-asp-net-mvc.aspx
PartialViewResult and JSONReuslt inherit from the base class ActionResult. so if return type is decided dynamically declare method output as ActionResult.
public ActionResult DynamicReturnType(string parameter)
{
if (parameter == "JSON")
return Json("<JSON>", JsonRequestBehavior.AllowGet);
else if (parameter == "PartialView")
return PartialView("<ViewName>");
else
return null;
}
For folks who have upgraded to MVC 3 here is a neat way
Using MVC3 and Json
public ActionResult GetExcelColumn()
{
List<string> lstAppendColumn = new List<string>();
lstAppendColumn.Add("First");
lstAppendColumn.Add("Second");
lstAppendColumn.Add("Third");
return Json(new { lstAppendColumn = lstAppendColumn, Status = "Success" }, JsonRequestBehavior.AllowGet);
}
}
Flexible approach to produce different outputs based on the request
public class AuctionsController : Controller
{
public ActionResult Auction(long id)
{
var db = new DataContext();
var auction = db.Auctions.Find(id);
// Respond to AJAX requests
if (Request.IsAjaxRequest())
return PartialView("Auction", auction);
// Respond to JSON requests
if (Request.IsJsonRequest())
return Json(auction);
// Default to a "normal" view with layout
return View("Auction", auction);
}
}
The Request.IsAjaxRequest() method is quite simple: it merely checks the HTTP headers for the incoming request to see if the value of the X-Requested-With header is XMLHttpRequest, which is automatically appended by most browsers and AJAX frameworks.
Custom extension method to check whether the request is for json or not so that we can call it from anywhere, just like the Request.IsAjaxRequest() extension method:
using System;
using System.Web;
public static class JsonRequestExtensions
{
public static bool IsJsonRequest(this HttpRequestBase request)
{
return string.Equals(request["format"], "json");
}
}
Source : https://www.safaribooksonline.com/library/view/programming-aspnet-mvc/9781449321932/ch06.html#_javascript_rendering
I want to pass error message to Blueimp jQuery File Upload plugin. I use ASP.NET MVC and throw my own exception when some conditions are appeared (i.e. file is not real image, only image exception or image is too wide etc).
var file = Request.Files[i];
_service.ImageValidation(file.InputStream);
public void ImageValidation(System.IO.Stream fileStream)
{
Bitmap bmp = null;
try
{
bmp = new Bitmap(fileStream, false);
}
catch
{
throw new NoImageException();
}
if (bmp.Width > bmp.Height && (bmp.Width < 1024 || bmp.Height < 768))
throw new ImageDimensionTooSmall();
if ((bmp.Width <= bmp.Height) && (bmp.Width < 768 || bmp.Height < 1024))
throw new ImageDimensionTooSmall();
fileStream.Position = 0;
}
on client side I try to catch error by the following way:
$('#fileupload').fileupload({
url: '/SmartphonePhotographer/ManageFiles?ResponseID=' + ResponseID,
error: function (e, data) {
alert('error');
}
});
'data' variable always has 'error' value. 'e' has many properties, including statusText='Internal server error' and responseText (html page with exception). Question - how can I pass error message on server side to catch it on client side (maybe, there is an json format for errors, but I did not find it in documentation)
It goes to the error event because you are throwing an exception in your server side code. So the ajax call is getting a 500 internal error response.
What you can do is, instead of throwing an exception, return a json response with the error messages.
[HttpPost]
public ActionResult SaveImage()
{
if(IsFileNotValid()) //your method to validate the file
{
var customErrors = new List<string> {"File format is not good",
"File size is too bib"};
return Json(new { Status = "error", Errors = customErrors });
}
//Save/Process the image
return Json ( new { Status="success", Message="Uploaded successfully" });
}
And in the done() event, you can inspect the json response and show the error messages as needed.
$('#fileupload').fileupload({
url: '/SmartphonePhotographer/ManageFiles?ResponseID=' + ResponseID,
error: function (e, data,txt) {
alert('error' + txt);
}
}).done(function(response){
if(response.Status==="error")
{
$.each(services.Errors, function (a, b) {
alert(b);
});
}
});
With this approach, you can send multiple validation errors back to the client and client can process(show to user ?) it.
MVC 6
In MVC6, you can return an HttpStatusCode response directly from the MVC controller action. So no need to send a JSON response yourself.
[HttpPost]
public IActionResult SaveImage()
{
var customErrors = new List<string> { "File format is not good",
"File size is too bib" };
return HttpBadRequest(customErrors);
}
This will send a 400 Response to the caller with the data we passed(the list of errors) in the response. So you can access the responseJSON property of your error xHr object of the error event to get it
error: function (a, b, c) {
$.each(a.responseJSON, function (a, b) {
alert(b);
});
}
I agree your issue is that you are throwing an exception versus returning a controlled response. Most frameworks look for status codes in the 400x or 500x. So you want to return a friendly json object and a status code in those ranges. If you do that your data object in the error block will be what you returned.
MVC Land:
//get a reference to request and use the below.
return this.Request.CreateResponse(HttpStatusCode.BadRequest, "Your message here");
Web Api 2
Use an IHttpActionResult and return BadRequest("My error message"); If you do that it will set your status code and return the response as the data.
I need a cross domain web api method to return valid jsonp to some javascript from C#. I can't seem to make this magic happen. I've looked around the web and can't find a start to end example that fits my needs and works... Fiddler shows that I'm returning valid json data but when I hit a breakpoint in F12 dev tools or firebug the result is a failure message.
Here is what I've currently got:
C#
/// <summary>
/// POST: /Instance/RefreshItem
/// </summary>
/// <param name="instanceId"></param>
/// <returns>Json</returns>
[HttpPost]
public System.Web.Mvc.JsonResult RefreshItem(int instanceId, Guid customerId)
{
try
{
var clientConnection = Manager.ValidateInstance(customerId, instanceId);
clientConnection.RefreshItem();
var result = new MethodResult()
{
Success = true,
Value = instanceId,
Message = "Item successfully refreshed."
};
return new System.Web.Mvc.JsonResult() { Data = result };
}
catch (Exception ex)
{
Manager.LogException(_logger, ex, customerId, instanceId);
var result = new MethodResult()
{
Success = false,
Value = instanceId,
Message = ex.GetBaseException().Message
};
return new System.Web.Mvc.JsonResult() { Data = result };
}
}
JS
Example.RefreshItem = function ()
{
Example.SDK.JQuery.getSettings(
function (settings, userId, userLocaleId)
{
alert("Attempting to refresh item for instance " + settings.ConnectionId + "\r\nThis may take awhile.");
var url = settings.SystemUrl + "/Api/WebApiServices/ExampleAdmin/RefreshItem?customerId=" + settings.CustomerId + "&instanceId=" + settings.ConnectionId;
$.ajax({
url: url,
dataType: "jsonp",
jsonpCallback: 'RefreshItemCallback',
success: RefreshItemCallback
})
},
Example.SDK.JQuery.defaultErrorCallback
);
}
function RefreshItemCallback(data)
{
alert(data.d.Message);
}
I've also tried $.Post().Always() with the same results.
What am I doing wrong???
I think your problem is that you're instantiating a JsonResult instead of using the Json method.
Presumably the C# method you have is in a controller, so instead of
return new System.Web.Mvc.JsonResult() { Data = result };
do:
return Json(result);
This method probably sets some of the other properties of the JsonResult that, when not set, will not be properly received by the client.
See how Microsoft only shows you how to create a JsonResult via the Json method on MSDN
Note that the same is probably true with methods like View, Content, and File.
Fight all week unable to find an answer until you ask the question somewhere... Within 30 minutes of asking I found this: http://bob.ippoli.to/archives/2005/12/05/remote-json-jsonp/ which was exactly what I needed.
Thanks to all who posted.
Been getting a "parsererror" from jquery for an Ajax request, I have tried changing the POST to a GET, returning the data in a few different ways (creating classes, etc.) but I cant seem to figure out what the problem is.
My project is in MVC3 and I'm using jQuery 1.5
I have a Dropdown and on the onchange event I fire off a call to get some data based on what was selected.
Dropdown: (this loads the "Views" from the list in the Viewbag and firing the event works fine)
#{
var viewHtmls = new Dictionary<string, object>();
viewHtmls.Add("data-bind", "value: ViewID");
viewHtmls.Add("onchange", "javascript:PageModel.LoadViewContentNames()");
}
#Html.DropDownList("view", (List<SelectListItem>)ViewBag.Views, viewHtmls)
Javascript:
this.LoadViewContentNames = function () {
$.ajax({
url: '/Admin/Ajax/GetViewContentNames',
type: 'POST',
dataType: 'json',
data: { viewID: $("#view").val() },
success: function (data) {
alert(data);
},
error: function (data) {
debugger;
alert("Error");
}
});
};
The above code successfully calls the MVC method and returns:
[{"ViewContentID":1,"Name":"TopContent","Note":"Content on the top"},
{"ViewContentID":2,"Name":"BottomContent","Note":"Content on the bottom"}]
But jquery fires the error event for the $.ajax() method saying "parsererror".
I recently encountered this problem and stumbled upon this question.
I resolved it with a much easier way.
Method One
You can either remove the dataType: 'json' property from the object literal...
Method Two
Or you can do what #Sagiv was saying by returning your data as Json.
The reason why this parsererror message occurs is that when you simply return a string or another value, it is not really Json, so the parser fails when parsing it.
So if you remove the dataType: json property, it will not try to parse it as Json.
With the other method if you make sure to return your data as Json, the parser will know how to handle it properly.
See the answer by #david-east for the correct way to handle the issue
This answer is only relevant to a bug with jQuery 1.5 when using the file: protocol.
I had a similar problem recently when upgrading to jQuery 1.5. Despite getting a correct response the error handler fired. I resolved it by using the complete event and then checking the status value. e.g:
complete: function (xhr, status) {
if (status === 'error' || !xhr.responseText) {
handleError();
}
else {
var data = xhr.responseText;
//...
}
}
You have specified the ajax call response dataType as:
'json'
where as the actual ajax response is not a valid JSON and as a result the JSON parser is throwing an error.
The best approach that I would recommend is to change the dataType to:
'text'
and within the success callback validate whether a valid JSON is being returned or not, and if JSON validation fails, alert it on the screen so that its obvious for what purpose the ajax call is actually failing. Have a look at this:
$.ajax({
url: '/Admin/Ajax/GetViewContentNames',
type: 'POST',
dataType: 'text',
data: {viewID: $("#view").val()},
success: function (data) {
try {
var output = JSON.parse(data);
alert(output);
} catch (e) {
alert("Output is not valid JSON: " + data);
}
}, error: function (request, error) {
alert("AJAX Call Error: " + error);
}
});
the problem is that your controller returning string or other object that can't be parsed.
the ajax call expected to get Json in return. try to return JsonResult in the controller like that:
public JsonResult YourAction()
{
...return Json(YourReturnObject);
}
hope it helps :)
There are lots of suggestions to remove
dataType: "json"
While I grant that this works it's ignoring the underlying issue. If you're confident the return string really is JSON then look for errant whitespace at the start of the response. Consider having a look at it in fiddler. Mine looked like this:
Connection: Keep-Alive
Content-Type: application/json; charset=utf-8
{"type":"scan","data":{"image":".\/output\/ou...
In my case this was a problem with PHP spewing out unwanted characters (in this case UTF file BOMs). Once I removed these it fixed the problem while also keeping
dataType: json
Your JSON data might be wrong. http://jsonformatter.curiousconcept.com/ to validate it.
Make sure that you remove any debug code or anything else that might be outputting unintended information. Somewhat obvious, but easy to forgot in the moment.
I don't know if this is still actual but problem was with Encoding. Changing to ANSI resolved the problem for me.
If you get this problem using HTTP GET in IE I solved this issue by setting the cache: false.
As I used the same url for both HTML and json requests it hit the cache instead of doing a json call.
$.ajax({
url: '/Test/Something/',
type: 'GET',
dataType: 'json',
cache: false,
data: { viewID: $("#view").val() },
success: function (data) {
alert(data);
},
error: function (data) {
debugger;
alert("Error");
}
});
you should remove the dataType: "json". Then see the magic... the reason of doing such thing is that you are converting json object to simple string.. so json parser is not able to parse that string due to not being a json object.
this.LoadViewContentNames = function () {
$.ajax({
url: '/Admin/Ajax/GetViewContentNames',
type: 'POST',
data: { viewID: $("#view").val() },
success: function (data) {
alert(data);
},
error: function (data) {
debugger;
alert("Error");
}
});
};
incase of Get operation from web .net mvc/api, make sure you are allow get
return Json(data,JsonRequestBehavior.AllowGet);
If you don't want to remove/change dataType: json, you can override jQuery's strict parsing by defining a custom converter:
$.ajax({
// We're expecting a JSON response...
dataType: 'json',
// ...but we need to override jQuery's strict JSON parsing
converters: {
'text json': function(result) {
try {
// First try to use native browser parsing
if (typeof JSON === 'object' && typeof JSON.parse === 'function') {
return JSON.parse(result);
} else {
// Fallback to jQuery's parser
return $.parseJSON(result);
}
} catch (e) {
// Whatever you want as your alternative behavior, goes here.
// In this example, we send a warning to the console and return
// an empty JS object.
console.log("Warning: Could not parse expected JSON response.");
return {};
}
}
},
...
Using this, you can customize the behavior when the response cannot be parsed as JSON (even if you get an empty response body!)
With this custom converter, .done()/success will be triggered as long as the request was otherwise successful (1xx or 2xx response code).
I was also getting "Request return with error:parsererror." in the javascript console.
In my case it wasn´t a matter of Json, but I had to pass to the view text area a valid encoding.
String encodedString = getEncodedString(text, encoding);
view.setTextAreaContent(encodedString);
I have encountered such error but after modifying my response before sending it to the client it worked fine.
//Server side
response = JSON.stringify('{"status": {"code": 200},"result": '+ JSON.stringify(result)+'}');
res.send(response); // Sending to client
//Client side
success: function(res, status) {
response = JSON.parse(res); // Getting as expected
//Do something
}
I had the same problem, turned out my web.config was not the same with my teammates.
So please check your web.config.
Hope this helps someone.
I ran into the same issue. What I found to solve my issue was to make sure to use double quotes instead of single quotes.
echo "{'error':'Sorry, your file is too large. (Keep it under 2MB)'}";
-to-
echo '{"error":"Sorry, your file is too large. (Keep it under 2MB)"}';
The problem
window.JSON.parse raises an error in $.parseJSON function.
<pre>
$.parseJSON: function( data ) {
...
// Attempt to parse using the native JSON parser first
if ( window.JSON && window.JSON.parse ) {
return window.JSON.parse( data );
}
...
</pre>
My solution
Overloading JQuery using requirejs tool.
<pre>
define(['jquery', 'jquery.overload'], function() {
//Loading jquery.overload
});
</pre>
jquery.overload.js file content
<pre>
define(['jquery'],function ($) {
$.parseJSON: function( data ) {
// Attempt to parse using the native JSON parser first
/** THIS RAISES Parsing ERROR
if ( window.JSON && window.JSON.parse ) {
return window.JSON.parse( data );
}
**/
if ( data === null ) {
return data;
}
if ( typeof data === "string" ) {
// Make sure leading/trailing whitespace is removed (IE can't handle it)
data = $.trim( data );
if ( data ) {
// Make sure the incoming data is actual JSON
// Logic borrowed from http://json.org/json2.js
if ( rvalidchars.test( data.replace( rvalidescape, "#" )
.replace( rvalidtokens, "]" )
.replace( rvalidbraces, "")) ) {
return ( new Function( "return " + data ) )();
}
}
}
$.error( "Invalid JSON: " + data );
}
return $;
});
</pre>
I have this controller method:
public JsonResult List(int number) {
var list = new Dictionary <int, string> ();
list.Add(1, "one");
list.Add(2, "two");
list.Add(3, "three");
var q = (from h in list where h.Key == number select new {
key = h.Key,
value = h.Value
});
return Json(list);
}
On the client side, have this jQuery script:
$("#radio1").click(function() {
$.ajax({
url: "/Home/List",
dataType: "json",
data: {
number: '1'
},
success: function(data) {
alert(data)
},
error: function(xhr) {
alert(xhr.status)
}
});
});
I always get an error code 500. What's the problem?
Thank you
If you saw the actual response, it would probably say
This request has been blocked because
sensitive information could be
disclosed to third party web sites
when this is used in a GET request. To
allow GET requests, set
JsonRequestBehavior to AllowGet.
You'll need to use the overloaded Json constructor to include a JsonRequestBehavior of JsonRequestBehavior.AllowGet such as:
return Json(list, JsonRequestBehavior.AllowGet);
Here's how it looks in your example code (note this also changes your ints to strings or else you'd get another error).
public JsonResult List(int number) {
var list = new Dictionary<string, string>();
list.Add("1", "one");
list.Add("2", "two");
list.Add("3", "three");
var q = (from h in list
where h.Key == number.ToString()
select new {
key = h.Key,
value = h.Value
});
return Json(list, JsonRequestBehavior.AllowGet);
}
While JustinStolle's answer solves your problem, I would pay attention to the error provided from the framework. Unless you have a good reason to want to send your data with the GET method, you should aim to send it with the POST method.
The thing is, when you use the GET method, your parameters gets added to your request url instead of added to the headers/body of your request. This might seem like a tiny difference, but the error hints why it's important. Proxy servers and other potential servers between the sender and the receiver are prone to logging the request url and often ignore the headers and/or body of the request. This information is also often regarded as non important/secret so any data exposed in the url is much less secure by default.
The best practice is then to send your data with the POST method so your data is added to the body instead of the url. Luckily this is easily changed, especially since you're using jquery. You can either use the $.post wrapper or add type: "POST" to your parameters:
$.ajax({
url: "/Home/List",
type: "POST",
dataType: "json",
data: { number: '1' },
success: function (data) { alert(data) },
error: function (xhr) { alert(xhr.status) }
});