xamarin.forms - Xamarin Forms ListView不在iOS，HttpClient中显示数据

问题描述

我有一个 Xaml Page ListView，可以在 UWP 中正确显示数据，但在 iOS 中无法正确显示数据。我正在使用 HttpClient 从连接到本地计算机上运行的 SQL Server 的 localhost webapi 获取数据。我认为这与使用 HttpClient 的 NSUrlSession 设置有关。有什么建议么？这是 Xaml 页面。

<?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:telerikDataControls="clr-namespace:Telerik.XamarinForms.DataControls;assembly=Telerik.XamarinForms.DataControls"
             xmlns:viewModels="clr-namespace:SxQiApp.ViewModels;assembly=SxQiApp"
             xmlns:telerikListView="clr-namespace:Telerik.XamarinForms.DataControls.ListView;assembly=Telerik.XamarinForms.DataControls"
             x:Class="SxQiApp.DailyCasePage">

    <ContentPage.BindingContext>
        <viewModels:VSxCaseViewModel />
    </ContentPage.BindingContext>

    <ContentPage.Content>
        <telerikDataControls:RadListView x:Name="listView"
                                         ItemsSource="{Binding SxCases}"
                                         ItemTapped="listView_ItemTappedAsync"                                      
                                         SelectedItem="{Binding SelectedSxCase, Mode=TwoWay}">
            <telerikDataControls:RadListView.ItemTemplate>
                <DataTemplate>
                    <telerikListView:ListViewTemplateCell>
                        <telerikListView:ListViewTemplateCell.View>
                            <StackLayout>
                                <Label Text="Surgery Cases" />
                                <Label Text="{Binding Facesheet}" />
                                <Label Text="{Binding Record}" />
                            </StackLayout>
                        </telerikListView:ListViewTemplateCell.View>
                    </telerikListView:ListViewTemplateCell>
                </DataTemplate>
            </telerikDataControls:RadListView.ItemTemplate>
        </telerikDataControls:RadListView>
    </ContentPage.Content>
</ContentPage>

这是后面的代码。

using System.Threading.Tasks;
using SxQiApp.Models;
using SxQiApp.ViewModels;
using Xamarin.Forms;

namespace SxQiApp
{
    // XamlC is set in App.xaml.cs
    //[XamlCompilation(XamlCompilationOptions.Compile)]
    public partial class DailyCasePage : ContentPage
    {
        public DailyCasePage()
        {
            InitializeComponent();
        }

        private async void listView_ItemTappedAsync(object sender, Telerik.XamarinForms.DataControls.ListView.ItemTapEventArgs e)
        {
            var sxcase = e.Item as SxCase;

            if (sxcase != null)
            {
                var SxCaseViewModel = new SxCaseViewModel();

                if (SxCaseViewModel != null)
                {
                    SxCaseViewModel.SelectedSxCase = sxcase;

                    await Navigation.PushAsync(new EditSxCasePage(SxCaseViewModel));
                }
            }
        }
    }
}

这是视图模型。

using SxQiApp.Models;
using SxQiApp.Services;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
using Xamarin.Forms;

namespace SxQiApp.ViewModels
{
    public class VSxCaseViewModel : INotifyPropertyChanged
    {
        private List<SxCase> _sxcase;
        private VSxCaseDataService _vsxCaseDataService = new VSxCaseDataService();

        private SxCase _selectedSxCase;

        public SxCase SelectedSxCase
        {
            get { return _selectedSxCase; }
            set
            {
                _selectedSxCase = value;
                OnPropertyChanged();
            }
        }

        public List<SxCase> SxCases
        {
            get
            {
                return _sxcase;
            }
            set
            {
                _sxcase = value;
                OnPropertyChanged();
            }
        }

        public ICommand AddRecordCommand => new Command(async () =>
        {

            await _vsxCaseDataService.PostSxCase(SelectedSxCase);

        });

        //public ICommand EditSxCaseCommand => new Command(async () =>
        //{

        //    await _vsxCaseDataService.PutSxCase(SelectedSxCase);

        //});

        public Command EditSxCaseCommand
        {
            get
            {
                return new Command(async () =>
                {
                    var sxCaseDataService = new SxCaseDataService();
                    await sxCaseDataService.PutSxCase(_selectedSxCase.Id, _selectedSxCase);
                });
            }
        }



        public VSxCaseViewModel()
        {
            SelectedSxCase = new SxCase();
            GetSxCases();
        }

        public event PropertyChangedEventHandler PropertyChanged;

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

        private async Task GetSxCases()
        {


            SxCases = await _vsxCaseDataService.GetSxCases();
        }


    }
}

这是服务代码

using Newtonsoft.Json;
using SxQiApp.Models;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;

namespace SxQiApp.Services
{
    class VSxCaseDataService
    {
        private string Url = "http://localhost:19952/api/vsxcases/";

        public async Task<List<SxCase>> GetSxCases()
        {
            var httpClient = new HttpClient();

            var json = await httpClient.GetStringAsync(Url);

            var sxcases = JsonConvert.DeserializeObject<List<SxCase>>(json);


            return sxcases;
        }

        public async Task PostSxCase(SxCase sxcase)
        {
            var httpClient = new HttpClient();

            var json = JsonConvert.SerializeObject(sxcase);

            StringContent content = new StringContent(json);

            content.Headers.ContentType = new MediaTypeHeaderValue("application/json");

            var result = await httpClient.PostAsync(Url, content);

        }

        public async Task PutSxCase(int sxcaseid, SxCase selectedSxCase)
        {
            var httpClient = new HttpClient();

            var json = JsonConvert.SerializeObject(selectedSxCase);

            StringContent content = new StringContent(json);

            content.Headers.ContentType = new MediaTypeHeaderValue("application/json");

            var result = await httpClient.PutAsync(Url + sxcaseid, content);

        }

    }
}

标签： xamarin.formshttpclientxamarin.forms.listview

xamarin.forms - Xamarin Forms ListView不在iOS，HttpClient中显示数据

问题描述

解决方案

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