How to Deserialize from web service JSON array or object?

问题

I created one web service application in windows phone 7. this is JSON array get from belowed uri. ...[{"id":4,"name":"Bangalore"},{"id":1,"name":"Chennai"},{"id":3,"name":"Hyderabad"},{"id":2,"name":"Mumbai"}]...

List item = (List)ds.ReadObject(msnew); In this line one bug(it says while run).

There was an error deserializing the object of type.Data at the root level is invalid. Line 1, position 1.

coding:

public MainPage() { InitializeComponent(); }

    [DataContract]
    public class Item
    {           

        [DataMember]
        public int id
        {
            get;
            set;
        }

        [DataMember]
        public string name
        {
            get;
            set;
        }
    }
    private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
    {
        WebClient wc = new WebClient();
        wc.DownloadStringAsync(new Uri("http://75.101.161.83:8080/CityGuide/Cities?authId=CITY4@$pir*$y$t*m$13GUID*5"));
        wc.DownloadStringCompleted += new DownloadStringCompletedEventHandler(wc_DownloadStringCompleted);
    }

    void wc_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
    {
       string MyJsonString = e.Result;
      // MessageBox.Show(e.Result);
       DataContractSerializer ds = new DataContractSerializer(typeof(Item));
       MemoryStream msnew = new MemoryStream(Encoding.UTF8.GetBytes(MyJsonString));
       List<Item> item = (List<Item>)ds.ReadObject(msnew);
    }

回答1:

There are 2 mistakes in what you're trying to do.

You're using DataContractSerializer instead of DataContractJsonSerializer. The one you're trying to use is expecting XML, not JSON.
You're trying to deserialize to a single Item and then convert that to a List<Item>, rather than an array, which is what json contains.

Try this instead:

  var ds = new DataContractJsonSerializer(typeof(Item[]));
  var msnew = new MemoryStream(Encoding.UTF8.GetBytes(MyJsonString));
  Item[] items = (Item[])ds.ReadObject(msnew);

If you later wanted to, you could convert the array to a list.

回答2:

You can add System.Json library from Silverlight SDK.
It isn't compiled for WP7, but for me it is working fine.

来源：https://stackoverflow.com/questions/4439020/how-to-deserialize-from-web-service-json-array-or-object

标签

.net

silverlight-4.0

c#-4.0

windows-phone-7