Help deserializing JSON object with List<> objects.

Question

_{Tuesday, October 27, 2009 7:03 PM}

Hi!

I'm having trouble deserializing the following object in a .net 3.5 webservice.

The webservice looks like this:

[WebMethod]
public bool UpdateGroupBooking(GroupBooking groupBooking) {
     if (GroupBookings.CreateGroupBooking(groupBooking)) {
         return true;
     } else {
         return false;
     }
}

The data it receives looks like this:

{"groupBooking":{"bookingNumber":"Karina Randers","navisionBookingNumber":"51035","bookingId":0,"password":"","destinationCode":"VALT","maxParticipants":10,"arrivalDate":"2010-02-12T23:00:00.000Z","departureDate":"2010-02-19T23:00:00.000Z","depositPaymentDate":"2009-10-26T23:00:00.000Z","balancePaymentDate":"2009-12-31T23:00:00.000Z","prices":[{"__type":"DANSKIXtreme.data.GroupPrice","id":0,"transportType":1,"salesPrice":0,"maxParticipants":0}]}}

My problem lies with the "prices" object.

It's of the type PriceGroupCollection which is a List<GroupPrice>

Without the "__type" declaration the deserializer cannot recognize the object, and with the  "__type" declaration I get the following error:

Operation is not valid due to the current state of the object.

In my GroupBooking class I have the prices object like this:

public GroupPriceCollection prices { get; set; }

The GroupPrice class looks like this:

    [DataContract]
    public class GroupPrice {
        /// <summary>
        /// Gets or sets the id.
        /// </summary>
        /// <value>The id.</value>
        [DataMember]
        public int id { get; set; }

        /// <summary>
        /// Gets or sets the sales price.
        /// </summary>
        /// <value>The sales price.</value>
        [DataMember]
        public int salesPrice { get; set; }

        /// <summary>
        /// Gets or sets the type of the transport.
        /// </summary>
        /// <value>The type of the transport.</value>
        [DataMember]
        public int transportType { get; set; }

        /// <summary>
        /// Gets or sets the max participants.
        /// </summary>
        /// <value>The max participants.</value>
        [DataMember]
        public int maxParticipants { get; set; }
    }

If I don't send along the prices object everything deserializes perfectly

What am I doing wrong?

If you need more info please let me know!

Regards,

Peter

All replies (5)

_{Thursday, October 29, 2009 2:39 AM ✅Answered}

 Did you set it as scriptmethod? Please check this link: http://forums.silverlight.net/forums/t/9726.aspx

_{Thursday, October 29, 2009 3:56 AM ✅Answered}

Hi,

U might have to call the Deserialize function recursively, but I'll show you how Deserialize a collection into List<T>.

System.Web.Script.Serialization.JavaScriptSerializer serializer = new System.Web.Script.Serialization.JavaScriptSerializer();

List<GroupPrice> groupPriceList = null;

groupPriceList = serializer.Deserialize<List<GroupPrice>>(jsonInput);

_{Thursday, October 29, 2009 6:41 PM ✅Answered}

Thanks for your help guys. I managed to get it working by passing the object as a string and then deserialize it using json.net which supports deserialization of nested list objects.

_{Wednesday, October 28, 2009 12:39 AM}

Hi,

You could use System.Web.Script.Serialization.JavaScriptSerializer class. It supports the method Deserialize using which you could easily deserialize JSON. More information here,

http://msdn.microsoft.com/en-us/library/system.web.script.serialization.javascriptserializer.aspx

Hope that helps!

_{Wednesday, October 28, 2009 5:07 AM}

Hi!

Thanks for your reply but I'm not sure this is what I'm looking for.

The class deserializes fine when I'm not including this part:

"prices":[{"__type":"project.data.GroupPrice","id":0,"transportType":1,"salesPrice":0,"maxParticipants":0}]

In my json-string.

I don't call the deserializer specifically - I just tell the webmethod which object is getting passed in like this:

public bool UpdateGroupBooking(GroupBooking groupBooking)

"prices" is of type "GroupPriceCollection" (List<GroupPrice>) which is declared in the GroupBooking class like this:

public GroupPriceCollection prices { get; set; }

Why do I get the error message:

"Operation is not valid due to the current state of the object."

//Peter