Webservices xamarin sqlite

i'm new in xamarin, i need help please,

I have data in my database MySql and i went to import it into a local database Sqlite, i craete a websevice that give me a data in jSon fomart ( sérialize) and now i try to consomme this webservice and get a data in my phone application into a sqlite database, but it doesn't work

can someone help me please

i copy what i tried

Class activitees:

 [Table("activitees")] 
class activitees
{
    public activitees()
    {

    }

    public int id { get; set; }
    public string title { get; set; }
    public string titlean { get; set; }


}

Class CreateDB

 public class CreateDB
{

    public string Creer()
    {
        var sortie = "";
        sortie += "création de la bdd";


        string dbPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Personal), "test.db3");
        var db = new SQLiteConnection(dbPath);

        sortie += "\nDB creer";
        db.CreateTable<activitees>();

        return sortie;

    }



    public async void Readactivitees()
    {


            var client = new WebClient();
            var response = client.DownloadString(new Uri("http://localhost:54001/WebService.asmx"));

            List<activitees> activity = JsonConvert.DeserializeObject<List<activitees>>(response);
            foreach (activitees obj in activity)
            {
                //var newActivitees = new activitees();
                //newActivitees.title = obj.title;
                //activitees.Insert(newActivitees);

                // Console.WriteLine(obj.title);
                //Console.WriteLine(obj.titlean);



                string dbPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Personal), "test.db3");
                var db = new SQLiteConnection(dbPath);

                activitees item = new activitees();
                item.title = obj.title;
                db.Insert(item);




            }
        }

Class MainActivity

public class MainActivity : Activity
{


    protected override void OnCreate(Bundle bundle)
    {
        base.OnCreate(bundle);

        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.Main);

        // Creation de base de donnée

        Button btnCreateDB = FindViewById<Button>(Resource.Id.btnCreateDB);

        btnCreateDB.Click += btnCreateDB_Click;


        Button btnGetActivitees = FindViewById<Button>(Resource.Id.btnGetActivitees);
        btnGetActivitees.Click += btnGetActivitees_Click; 



    }


    void btnCreateDB_Click(object sender, EventArgs e)
    {
        CreateDB dbr = new CreateDB();

        var res = dbr.Creer();
        Toast.MakeText(this, res, ToastLength.Long).Show();

    }


    void btnGetActivitees_Click(object sender, EventArgs e)
    {

        CreateDB dbr = new CreateDB();
        dbr.Readactivitees();


    }


}

Thank you, hava a good day