Using C#, how do I construct a complex post object for use in a WebClient post?

Question

Background

Within my C# middle tier, I have a scheduled task that runs certain business logic every minute and then sends push notifications to iOS and Android devices accordingly. I use Urban Airship to facilitate the push notices which means that, in my code, I am just calling their API and then they handle the actual pushing to various devices. Here is what that code looks like:

public static void SendNotice(UaMessageModel messages)
{
    var audience = new NameValueCollection
        {
            {"alias", string.Join(", ", messages.UserIds)}
        };

    var notification = new NameValueCollection
        {
            {"alert", messages.Message}
        };

    var pushNotice = new NameValueCollection
        {
            {"audience", new JavaScriptSerializer().Serialize(audience)},
            {"notification", new JavaScriptSerializer().Serialize(notification)}
        };

    //ToDo: remove "validate" from URL when done testing.
    Utilities.PostWebRequest("https://go.urbanairship.com/api/push/validate/", "Basic XXXXXXXXX", pushNotice, "application/vnd.urbanairship+json; version=3;");
}


public class UaMessageModel
{
    public List<int> UserIds { get; set; }
    public string Message { get; set; }
}

Problem

When I put a break point at Utilities.PostWebRequest and hover over pushNotice, I only see the keys of the pushNotice NameValueCollection, but no values. Am I constructing this NameValueCollection incorrectly?

More Info

Whether pushNotice is constructed correctly or not, I still don't get any response from my WebClient post. This method works when I use just a simple, flat post object. Here is that code:

public static dynamic PostWebRequest(string url, string token, NameValueCollection obj, string accept)
{
    using (var wc = new WebClient())
    {
        wc.Headers.Add("Authorization", token);
        wc.Headers.Add("Accept", accept);
        return GetObjectFromJson(Encoding.UTF8.GetString(wc.UploadValues(url, "POST", obj)));
    }
}

Thanks in advance.

Answer 1

NameValueCollection is not a Dictionary. The JavascriptSerializer will not serialize it as you expect. To get your expected result you should convert the NameValueCollection to a Dictionary.

    NameValueCollection audience = new NameValueCollection();
    Data.Add("alias", "foobar");
    Data.Add("alias", "foobar2");

To output the values along with the keys you need to convert the NameValueCollection to a Dictionary like below:

    Dictionary<string, string> audienceDictionary = audience.AllKeys.ToDictionary(k => k, k => source[k]));

Our you can just use a Dictionary in your code instead of a NameValueCollection:

    Dictionary<string, string> audience = new Dictionary<string, string>();
    audience.Add("alias", string.Join(", ", messages.UserIds));

    Dictionary<string, string> notification = new Dictionary<string, string>();
    notification.Add("alert", messages.Message);

    Dictionary<string, string> pushNotice = new Dictionary<string, string>();
    pushNotice.Add("audience", new JavaScriptSerializer().Serialize(audience));
    pushNotice.Add("notification", new JavaScriptSerializer().Serialize(notification));

Edit:

Also take a look at this answer: https://stackoverflow.com/a/7003815/2488939