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Can you convert C# dictionary to Javascript associative array using asp.net mvc Json()

Answer 1

A:

Hi,

In json you have two main structures: an "array", this is a list of element, and an "object", a group of key-value pairs.

So for what you want to achieve the json method has to return a json object (debug the server side to see what is actually send to the client).

In javascript the json object will be directly mapped to a javascript object, and in javascript objects are also associative arrays

So to summarize:

Make sure the server returns a json object, then you can use it as some kind of dictionary in javascript.

davyM 2010-09-05 12:05:24

Answer 2

A:

Your code isn't valid - perhaps a typo?

$.post('/MyController/Refresh', function (data) {

           var calendarDictionary = data.Dict;

    }, "json");

Also, I've seen cases where a method needs the data param, even if it's empty {}.

Finally, the json should come back inside data.d - use firebug to console.log the response.

ScottE 2010-09-05 12:20:18

@ScottE - yes, that was just a typo in my post. i have corrected

ooo 2010-09-05 12:32:15

what's the downvote for? Please explain.

ScottE 2010-09-05 15:33:45

Answer 3

+1 A:

You probably could have been a little more specific about the it just blows up part but here's an example that works fine for me:

Model:

public class CalendarEvent
{
    public string Name { get; set; }
    public DateTime Date { get; set; }
    public int Id { get; set; }
}

Controller:

public class HomeController : Controller
{
    public ActionResult Index()
    {
        return View();
    }

    [HttpPost]
    public ActionResult Refresh()
    {
        var model = new[]
        {
            new CalendarEvent 
            {
                Id = 1,
                Name = "event 1",
                Date = DateTime.Now
            },
            new CalendarEvent 
            {
                Id = 2,
                Name = "event 2",
                Date = DateTime.Now
            },
            new CalendarEvent 
            {
                Id = 3,
                Name = "event 3",
                Date = DateTime.Now.AddDays(2)
            },
        }
        .ToList()
        .ConvertAll(a => new
        {
            a.Name,
            a.Id,
            Date = a.Date.ToString("MMM dd, yyyy"),
        })
        .GroupBy(r => r.Date)
        .ToDictionary(
            group => group.Key, 
            group => group.Select(x => new { x.Name, x.Id })
        );
        return Json(new { Dict = model });
    }
}

View:

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage" %>    
<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>JSON Test</title>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"&gt;&lt;/script&gt;
    <script type="text/javascript">
    $(function () {
        $.post('/home/refresh', function(data) {
            // TODO : manipulate the data.Dict here
        }, 'json');
    });
    </script>
</head>
<body>

</body>
</html>

Returned JSON:

{ "Dict": { "Sep 05, 2010": [ { "Name": "event 1", "Id": 1 },
                              { "Name": "event 2", "Id": 2 } ],
            "Sep 07, 2010": [ { "Name": "event 3", "Id": 3 } ] } }

Darin Dimitrov 2010-09-05 15:06:55

Answer 4

A:

You might want to look at the Json.NET library. It makes creating JSON representations of .Net objects very simple.

jsumners 2010-09-05 15:15:05

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Can you convert C# dictionary to Javascript associative array using asp.net mvc Json()

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