如何显示从ASP.NET Web应用程序到Xamarin.Forms的数据？

Question

I want all the records created in ASP.NET Web Application to be shown in my Mobile App Xamarin.Forms. What's happening to my program is that I was able to create records in my Web Application and save it, but I wasn't able to make it appear in my Xamarin.Forms Mobile app. I have created a MainViewModel that will get the records from the Web Application which I have binded to my MainPage. These are my codes:

MainPageMain.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
         xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
         xmlns:local="clr-namespace:XamarinDemoApp"
         x:Class="XamarinDemoApp.MainPageMain"
         xmlns:ViewModels="clr-namespace:XamarinDemoApp.ViewModels;assembly=XamarinDemoApp"
         BackgroundColor="Teal"
         Title=" Title Bar">



 <ContentPage.BindingContext>
     <ViewModels:MainViewModel/>
 </ContentPage.BindingContext>


 <StackLayout Orientation="Vertical">

   <ListView ItemsSource="{Binding EmployeesList}"
          HasUnevenRows="True">
     <ListView.ItemTemplate>
       <DataTemplate>
          <ViewCell>
        <StackLayout Orientation="Horizontal">
          <Label Text="{Binding Name}"
                  FontSize="24"/>
          <Label Text="{Binding Department}"
                  FontSize="24"/>

        </StackLayout>

      </ViewCell>

      </DataTemplate>

     </ListView.ItemTemplate>

    </ListView>

   <Label Text="This is the MainPage"/>

 </StackLayout>

MainViewModel.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using XamarinDemoApp.Models;
using XamarinDemoApp.Services;

namespace XamarinDemoApp.ViewModels
    {
public class MainViewModel : INotifyPropertyChanged
    {
    private List<Employee> _employeesList;

    public List<Employee> EmployeesList
    {
        get { return _employeesList; }
        set
        {
            _employeesList = value;
            OnPropertyChanged();
        }
    }

    public MainViewModel()
    {
      InitializeDataAsync();
    }

    private async Task InitializeDataAsync()
     {
         var employeesServices = new EmployeesServices();
         EmployeesList = await employeesServices.GetEmployeesAsync();
     }


    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged.Invoke(this, new PropertyChangedEventArgs(propertyName));

        }
    }
}

Answer 1

Make a separate API controller that you can use to call EmployeeList as a JSON object. That is the preferred way to do this kind of thing. Example:

public class EmployeeApiController : ApiController
{
   [HttpGet]
   public async Task<List<Employee>> Get()
   {
      return await employeesServices.GetEmployeesAsync();

   }
}