Sample:Passing a generic dictionary from Silverlight Client to Server

mamboer posted on Wednesday, March 18, 2009

A few hours ago,Rocky made a little fix on the Cals.Core.MobileDictionary<K,V>,now it can be serialized/deserialized correctly by both BinaryFormatter and Csla's MobileFormatter,although it has come restrictions on the generic parameters' type(type of K&V),it should work if both of your K&V,
1,are a primitive type such as int,string,etc.

2,have implemented the IMobileObject interface.

Now,i will define a custom criteria class,add a MobileDictionary<string,object> property to it,and then pass it from SL client to Server

Below is my criteria class:
[Serializable]
    public class DicCriteria : CriteriaBase {
        public DicCriteria():this(null) {
           
        }
        public DicCriteria(Dictionary<string,object> value) {
            if (value == null)
                _Value = new MobileDictionary<string, object>();
            else
            {
                _Value = new MobileDictionary<string, object>(value);
            }
        }
        private MobileDictionary<string, object> _Value;
        public MobileDictionary<string, object> Value
        {
            get {
                return _Value;
            }
            private set {
                if (_Value != value)
                    _Value = value;
            }
        }
        public DicCriteria Add(string key, object value)
        {
            if (!_Value.ContainsKey(key))
            {
                _Value.Add(key, value);
            }
            return this;
        }

        protected override void OnGetState(Csla.Serialization.Mobile.SerializationInfo info, StateMode mode)
        {
            //Note:Must serialize your MD property to byte[]
            //before adding to the info,because MF will new a 
            //DataContractSerializer for
            //List<SerializationInfo> type           
            //to do the serialization,and your
            //MobileDictionary is not a known type to it.           
            info.AddValue("_Value", MobileFormatter.Serialize(_Value));
            base.OnGetState(info, mode);
        }
        protected override void OnSetState(Csla.Serialization.Mobile.SerializationInfo info, StateMode mode)
        {
            _Value = MobileFormatter.Deserialize((byte[])info.Values["_Value"].Value) as MobileDictionary<string, object>;
            base.OnSetState(info, mode);
        }
    }


Now on your SL client,you can do:
            ...
            var criteria = new DicCriteria();
            criteria.Add("Name", "Levin").Add("Country","CN");
            dataPortalInstance.BeginFetch(criteria);
            ...

On your server side somewhere in Data access layer,it may be:

        public override L Fetch(CriteriaBase criteria)
        {
            if (criteria != null)
            {
                var list = (L)Activator.CreateInstance(typeof(L), true);
                IList<TDto> _list;

                using (UOWorker.Start(DatabaseKey))
                {
                    var crit = criteria as DicCriteria;
                    Check.Require(crit!=null,"A parameter of DicCriteria type is required!");
                    _list = _repository.FindAll(crit.Value);
                }

                list.Add(_list);
                MarkOld(list);
                return list;

            }
            return Fetch();
        }

That's it!