Adding Dropdown with Dynamic data [Picker] Also Getting data through WebAPI

Model is here :
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace XamarinWebServices.Models
{
public class CustomerViewModel
{
public int id { get; set; }
public string name { get; set; }
}

// ViewModel:
public class CustomerVM
{
    public CustomerViewModel Data { get; set; }
    public ObservableCollection<CustomerViewModel> CustomerList { get; set; }

    public CustomerVM()
    {
        CustomerList = new ObservableCollection<CustomerViewModel>();
    }
}

}

XAML file for Picker (Dropdown) :
<?xml version="1.0" encoding="utf-8" ?>




<Picker.Items>

</Picker.Items>
</Picker>

And here is the codeBehind with dynamic data through link [Working with Web Api in Xamarin.forms]:

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Threading.Tasks;

using Xamarin.Forms;
using XamarinWebServices.Models;

namespace XamarinWebServices
{
public partial class DropDown : ContentPage
{
CustomerVM viewModel;
public DropDown()
{
InitializeComponent();

        viewModel = new CustomerVM();
        BindingContext = viewModel;
    }

     async override protected void OnAppearing()
    {
        base.OnAppearing();
        var json = await GetCustomersAsync();
        List<CustomerVM> customers = JsonConvert.DeserializeObject<List<CustomerVM>>(json);
        foreach (CustomerVM c in customers)
        {
            if (c.Data != null)
            {
                string name = c.Data.name;
                int ID = c.Data.id;

                CustomerViewModel v = new CustomerViewModel();
                v.name = name; v.id = ID;
                CustomerList.Items.Add(name);
                viewModel.CustomerList.Add(v);
            }
        }

    }

    async Task<string> GetCustomersAsync()
    {
        var client = new HttpClient();

        client.BaseAddress = new Uri("http://www.doctorksa.com/webservices/");

        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        HttpResponseMessage response = await client.GetAsync("country");
        if (response.IsSuccessStatusCode)
        {
            string result = await response.Content.ReadAsStringAsync();
            return result;
        }
        else return response.ReasonPhrase;
    }
    void CustomerList_SelectIndexChanged(object sender, EventArgs args)
    {
        DisplayAlert("Test", "Ok", "Cancle", "Confirm");
    }

}

}

Hope this will help you in working with dropdown and Web API