c# - Serialize .NET Dictionary<string, string> into JSON Key Value Pair Object

Question

I need to get:

public class Package
{
    public Package()
    {
        name = "";
        type = new List<Dictionary<string, string>>();
    }

    public string name { get; set; }
    public List<Dictionary<string, string>> type { get; set; }
}

into:

{
    "name":"package_name",
    "type":
    {
        "http://random.url.as.key":"random/value"
    }
}

with:

Package package = new Package();
package.name = "package_name";
package.type.Add(new Dictionary<string, string>() { { "http://random.url.as.key", "random/value" } });

I get:

{
    "name":"package_name",
    "type":
    [
        [
            {
                "Key":"http://random.url.as.key",
                "Value":"random/value"
            }
        ]
    ]
}

while, with:

var package = new
{
    name = "package_name",
    type = new
    {
        http_random_url_as_key = "random/value"
    }
};

I get:

{
    "name":"package_name",
    "type":
    {
        "http_random_url_as_key":"random/value"
    }
}

I can't get the obsure http://random.url.as.key that I need. I have tried using JavaScriptSerializer, DataContractJsonSerializer, and Custom Convertor for Json.NET, all with limited success/shortcomings.

There must be a better way/something I'm overlooking to get a simple JSON Object over the wire!

Answer 1

Well, first off, for the first example, what you basically have is a list of collections of KeyValuePair<string,string> objects.

So, the reason that it gets converted to the JSON shown is this:

{
    "name":"package_name",
    "type":
    [ // List<Dictionary<string,string>>
        [ // Dictionary<string,string>, a list of KeyValuePair<string,string> objects
            { // KeyValuePair<string,string> object 
                "Key":"http://random.url.as.key",
                "Value":"random/value"
            }
        ]
    ]
}

As far as your second example, you are creating a dynamic object, containing a dynamic object, and each of the object's fields are what are providing the key value.

So, I would suggest ditching the outer List<> around the Dictionary<string,string>, then make use of the Newtonsoft.Json.Converters.KeyValuePairConverter object in the JSON.Net library when doing your serialization:

string json = JsonConvert.SerializeObject( package, new KeyValuePairConverter( ) );

Hope that helps.

EDIT

Okay, so I figured I should give a more concrete example

public class Package
{
    public Package()
    {
        name = "";
        type = new Dictionary<string, string>();
    }

    public string name { get; set; }
    public Dictionary<string, string> type { get; set; }
}

Package package = new Package();
package.name = "package_name";
package.type.Add("http://random.url.as.key", "random/value");
string json = JsonConvert.SerializeObject( package, new KeyValuePairConverter( ) );

This will get you the output

{
    "name":"package_name",
    "type":
    {
        "http://random.url.as.key":"random/value"
    }
}