get Facebook Pages in Windows Phone 7 using C# SDK - json

Question

I tried to figure this out using the Windows Phone sample from the Facebook C# SDK page, but have been unsuccessful.
Here's the main code:
private void GetPages()
{
var fb = new FacebookClient(_accessToken);
fb.GetCompleted += (o, e) =>
{
if (e.Error != null)
{
Dispatcher.BeginInvoke(() => MessageBox.Show(e.Error.Message));
return;
}
var result = (IDictionary<string, object>)e.GetResultData();
// returns data and paging from Facebook
Dispatcher.BeginInvoke(() =>
{
foreach (var item in result)
{
// Not sure if/how to use the custom classes here
//item has .Key and .Value
//.Key = data and .Value contains the key/value pais for each of the pages returned
}
});
};
fb.GetAsync("me/accounts");
}
// Custom Classes
public class FacebookPageCollection
{
[JsonProperty(PropertyName = "data")]
public FacebookPage[] data { get; set; }
[JsonProperty(PropertyName = "paging")]
public FacebookPagePaging paging { get; set; }
}
public class FacebookPage
{
[JsonProperty(PropertyName = "name")]
public string Name { get; set; }
[JsonProperty(PropertyName = "access_token")]
public string AccessToken { get; set; }
[JsonProperty(PropertyName = "category")]
public string Category { get; set; }
[JsonProperty(PropertyName = "id")]
public string Id { get; set; }
}
public class FacebookPagePaging
{
[JsonProperty(PropertyName = "previous")]
public Uri previous { get; set; }
[JsonProperty(PropertyName = "next")]
public Uri next { get; set; }
}
This is what the variable "result" returns:
{"data":[{"name":"value1","access_token":"value2","category":"value3","id":"value4","perms":["ADMINISTER","EDIT_PROFILE","CREATE_CONTENT","MODERATE_CONTENT","CREATE_ADS","BASIC_ADMIN"]},{"name":"value1","access_token":"value2","category":"value3","id":"value4","perms":["ADMINISTER","EDIT_PROFILE","CREATE_CONTENT","MODERATE_CONTENT","CREATE_ADS","BASIC_ADMIN"]}],"paging":{"next":"url"}}
What I'd like to do is retrieve and save details for each page.
I have been trying to figure this out and have looked over a number of other posts on here and elsewhere. I just don't have enough experience to figure it out.
Any help is appreciated.
Thank you.
Sri

Answer 1

Here is a trick to understanding how to work with json response in fb c# sdk.
Here is the mapping between Javascript JSON and C# JSON. (Notice there is no DateTime and another complex .net objects as it is not part of the JSON spec found in JSON.org)
JsonObject => keyvalue pairs => IDictionary<string, object> / IDictinary<string, dynamic>
JsonArray => array => IList<object> / IList<dynamic>
string => string
number => long/decimal
boolean => bool
Here is how you do the actual mapping.
var result = (IDictionary<string, object>)e.GetResultData();
var data = (IList<object>)result["data"];
foreach(var act in data) {
var account = (IDictionary<string,object>) act;
var name = (string)account["name"];
var accessToken = (string)account["access_token"];
var id = (string)account["id"];
// normalize to IList<string> permissions, so it is easier to work without casting.
var permissions = ((IList<object>)account["perms"]).Select(x => (string)x).ToList();
}