c# - Json write can not be serialized -

process:

1. create player class.

2. create player list<player>().

3. add players list.

4. write json serial file.

   when click on writejson button receive error:

   "type `'editplayers.player'` cannot serialized. consider marking  `datacontractattribute` attribute, , marking of members want serialized  `datamemberattribute` attribute.  if type collection, consider marking  `collectiondatacontractattribute`.see microsoft .net framework  documentation other supported types." 

question:

how mark list<player>() collectiondatacontractattribute.

class player {     public int memberid { get; set; }     public int gender { get; set; }     public string lname { get; set; }     public string fname { get; set; }     public int tee { get; set; }     public int team { get; set; }     public int flight { get; set; }     public int ohc { get; set; }     public decimal hcix { get; set; } }  private async void writejason_click(object sender, routedeventargs e) {     try     {         await writejsonasync();     }     catch     {      } }  private async void readjason_click(object sender, routedeventargs e) {     await deserializerjsonasync(); }  private list<player> buildobjectgraph() {     var players = new list<player>();     players.add(new player() {memberid=1, gender=0, lname="player", fname="new", tee=1, team=0, flight=0, ohc=0, hcix=0m});     players.add(new player() {memberid=2, gender=0, lname="draw", fname="blind", tee=1, team=0, flight=0, ohc=0, hcix=0m});     players.add(new player() {memberid=3, gender=0, lname="moles", fname="mike", tee=1, team=4, flight=1, ohc=2, hcix=2.0m});     players.add(new player() {memberid=4, gender=0, lname="broemeling", fname="donald", tee=1, team=4, flight=2, ohc=10, hcix=10.0m});     players.add(new player() {memberid=5, gender=0, lname="nelson", fname="david", tee=1, team=4, flight=3, ohc=11, hcix=11.7m});     players.add(new player() {memberid=6, gender=0, lname="moles", fname="david", tee=1, team=4, flight=4, ohc=20, hcix=20.0m});     players.add(new player() {memberid=7, gender=0, lname="player", fname="a", tee=1, team=1, flight=1, ohc=0, hcix=0m});     players.add(new player() {memberid=8, gender=0, lname="player", fname="b", tee=1, team=1, flight=2, ohc=0, hcix=0m});     players.add(new player() {memberid=9, gender=0, lname="player", fname="c", tee=1, team=1, flight=3, ohc=0, hcix=0m});     players.add(new player() {memberid=10,gender=0, lname="player", fname="d", tee=1, team=1, flight=4, ohc=0, hcix=0m});     return players; } private async task writejsonasync() {     var allplayers = buildobjectgraph();     var serializer = new datacontractjsonserializer(typeof(list<player>));     //using (var stream = await applicationdata.current.localfolder.openstreamforwriteasync(     //    jsonfilename,     //    creationcollisionoption.replaceexisting))     using (var stream = await applicationdata.current.localfolder.openstreamforwriteasync(     jsonfilename, creationcollisionoption.replaceexisting))     {         serializer.writeobject(stream, allplayers);     }     resulttextblock.text = "write succeeded"; } 

you don't need mark list<player>() collectiondatacontractattribute. instead, need make player class serializable datacontractjsonserializer, described documentation: types supported data contract serializer.

the easiest solution mark player serializable attribute:

[serializable] class player {     // remainder unchanged } 

alternatively annotate [datacontract] , [datamember] attributes:

[datacontract] class player {     [datamember]     public int memberid { get; set; }     [datamember]     public int gender { get; set; }     [datamember]     public string lname { get; set; }     [datamember]     public string fname { get; set; }     [datamember]     public int tee { get; set; }     [datamember]     public int team { get; set; }     [datamember]     public int flight { get; set; }     [datamember]     public int ohc { get; set; }     [datamember]     public decimal hcix { get; set; } } 

either way, list<player> serializable datacontractjsonserializer.

note data contract serialization opt-in must mark every property or field serialized [datamember].