如何在列表視圖中通過單擊項目打開另一個 xamarin 表單頁面

Question

您好，我有一個在 Xamarin 表單中制作的列表視圖，我想要它做的就是當用戶單擊列表視圖中的一個選項時，它會將它們帶到另一個 Xamarin 表單頁面，在我的情況下，它將是 ContactInfo

繼承人我的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" x:Class="WebSearch.CountySelect" Title="ReadyMo">
  <StackLayout Padding="0,20,0,0">
   <Label Text="ReadyMo" FontAttributes="Bold" HorizontalOptions="Center" />
    <ListView x:Name="listView">
      <ListView.ItemTemplate>
        <DataTemplate>
          <ViewCell>
            <Grid>
              <Grid.ColumnDefinitions>
                <ColumnDefinition Width="0.5*" />
                <ColumnDefinition Width="0.2*" />
                <ColumnDefinition Width="0.3*" />
              </Grid.ColumnDefinitions>
              <Label Text="{Binding Name}" FontAttributes="Bold" HorizontalOptions="Center">
              </Label>
            </Grid>
          </ViewCell>
        </DataTemplate>
      </ListView.ItemTemplate>
    </ListView>
  </StackLayout>
</ContentPage>

這是我的代碼：

using WebSearch;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Xamarin.Forms;

namespace WebSearch
{
    public partial class CountySelect : ContentPage
    {

        public CountySelect()
        {
            InitializeComponent();


            var name = new List<County>
            {
                      new County("Adair"),
                      new County("Andrew"),
                      new County("Atchison"),
                      new County("Audrain"),
                      new County("Barry"),
                      new County("Barton"),
                      new County("Bates"),
                      new County("Benton"),
                      new County("Bollinger"),
                      new County("Boone"),
                      new County("Buchanan"),
                      new County("Butler"),
                      new County("Caldwell"),
                      new County("Callaway"),
                      new County("Camden"),
                      new County("Cape Girardeau"),
                      new County("Carroll"),
                      new County("Carter"),
                      new County("Cass"),
                      new County("Cedar"),
                      new County("Chariton"),
                      new County("Christian"),
                      new County("Clark"),
                      new County("Clay"),
                      new County("Clinton"),
                      new County("Cole"),
                      new County("Cooper"),
                      new County("Crawford"),
                      new County("Dade"),
                      new County("Dallas"),
                      new County("Daviess"),
                      new County("DeKalb"),
                      new County("Dent"),
                      new County("Douglas"),
                      new County("Dunklin"),
                      new County("Franklin"),
                      new County("Gasconade"),
                      new County("Gentry"),
                      new County("Greene"),
                      new County("Grundy"),
                      new County("Harrison"),
                      new County("Henry"),
                      new County("Hickory"),
                      new County("Holt"),
                      new County("Howard"),
                      new County("Howell"),
                      new County("Iron"),
                      new County("Jackson"),
                      new County("Jasper"),
                      new County("Jefferson"),
                      new County("Johnson"),
                      new County("Knox"),
                      new County("Laclede"),
                      new County("Lafayette"),
                      new County("Lawrence"),
                      new County("Lewis"),
                      new County("Lincoln"),
                      new County("Linn"),
                      new County("Livingston"),
                      new County("Macon"),
                      new County("Madison"),
                      new County("Maries"),
                      new County("Marion"),
                      new County("McDonald"),
                      new County("Mercer"),
                      new County("Miller"),
                      new County("Mississippi"),
                      new County("Moniteau"),
                      new County("Monroe"),
                      new County("Montgomery"),
                      new County("Morgan"),
                      new County("New Madrid"),
                      new County("Newton"),
                      new County("Nodaway"),
                      new County("Oregon"),
                      new County("Osage"),
                      new County("Ozark"),
                      new County("Pemiscot"),
                      new County("Perry"),
                      new County("Pettis"),
                      new County("Phelps"),
                      new County("Pike"),
                      new County("Platte"),
                      new County("Polk"),
                      new County("Pulaski"),
                      new County("Putnam"),
                      new County("Ralls"),
                      new County("Randolph"),
                      new County("Ray"),
                      new County("Reynolds"),
                      new County("Ripley"),
                      new County("Saline"),
                      new County("Schuyler"),
                      new County("Scotland"),
                      new County("Scott"),
                      new County("Shannon"),
                      new County("Shelby"),
                      new County("St. Charles"),
                      new County("St. Clair"),
                      new County("St. Francois"),
                      new County("St. Louis City"),
                      new County("St. Louis County"),
                      new County("Ste. Genevieve"),
                      new County("Stoddard"),
                      new County("Stone"),
                      new County("Sullivan"),
                      new County("Taney"),
                      new County("Texas"),
                      new County("Vernon"),
                      new County("Warren"),
                      new County("Washington"),
                      new County("Wayne"),
                      new County("Webster"),
                      new County("Worth"),
                      new County("Wright")
            };

            listView.ItemsSource = name;
            listView.ItemTapped += async (sender, args) =>
            {
                var item = args.Item as County;
                if (item == null) return;
                await Navigation.PushAsync(new ContactInfo(item));
                listView.SelectedItem = null;
            };

            Content = listView;


        }


    }
}

我對 Xamarin Forms 非常陌生，所以任何幫助都會很棒:) 提前致謝！

Answer 1

所以我發現我的 app.cs 中的代碼是： public class App ：

Application

    {
        public App()
        {
            MainPage = new MyFirstPage();
        }
    }

當它需要時：

public class App : Application
{
    public App()
    {
        MainPage = new NavigationPage(new MyFirstPage());
    }
}

多一點研究大有幫助！ :)

Answer 2

應用類

public class App: Application
{
    public static NavigationPage MyNavigationPage;

    public App()
    {
        MyNavigationPage = new NavigationPage();
        MainPage = MyNavigation;
        MyNavigation.PushAsync(new Page_Countries, true);
    }
}

單擊 BindableProperty 項的自定義 ListView

 public class MyListView : ListView
    {


        public MyListView()
        {
            this.ItemTapped += this.OnItemTapped;

        }

        public static BindableProperty ItemClickCommandProperty = BindableProperty.Create<MyListView, ICommand>(x => x.ItemClickCommand, null);

        public ICommand ItemClickCommand {
            get { return (ICommand)this.GetValue(ItemClickCommandProperty); }
            set { this.SetValue(ItemClickCommandProperty, value); }
        }


        private void OnItemTapped(object sender, ItemTappedEventArgs e) {
            if (e.Item != null && this.ItemClickCommand != null && this.ItemClickCommand.CanExecute(e)) {
                this.ItemClickCommand.Execute(e.Item);
                this.SelectedItem = null;
            }
        }

    }

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:customcontrols="clr-namespace:MyNameSpace.CustomControls;assembly=MyNameSpace"
             x:Class="MyNameSpace.Views.Page_Countries"
             Title="Countries">

<customcontrols:MyListView
                x:Name="listOfCountries"
                VerticalOptions="Fill"
                HorizontalOptions="Fill"
                ItemsSource="{Binding PropertyCountries}"
                SelectedItem="{Binding PropertySelectedItem}"
                ItemClickCommand="{Binding CountryItemClickCommand}" <---
 <ListView.ItemTemplate>
            <DataTemplate>
              <ViewCell>
                <ViewCell.View>
                  <StackLayout
                      Orientation="Horizontal"
                      HorizontalOptions="Fill"
                      VerticalOptions="Center"
                      Padding="5,0,5,0"
                      Spacing="10">
<Label

                          HorizontalOptions="FillAndExpand"
                       LineBreakMode="TailTruncation"
                          VerticalOptions="Center"
                          Text="{Binding CountryName}" />
</StackLayout>
                </ViewCell.View>
              </ViewCell>
            </DataTemplate>
          </ListView.ItemTemplate>
        </customcontrols:MyListView>

視圖模型

class ViewModel_Countries
{
    private ObservableCollection<Models.Country> Countries;
    public ObservableCollection<Models.Country> PropertyCountries
    {
            set { SetProperty(ref Countries, value); }
            get { return Countries; }
    }

    private ICommand countryItemClickCommand;
    public ICommand CountryItemClickCommand;
    {
        get
        {
            return countryItemClickCommand ?? (countryItemClickCommand = new Command (async () => await ExecuteCountryClickCommand()));
        }
    }

private async Task ExecuteCountryClickCommand()
{
    App.MyNavigation.PushAsync(MyNewPage, true);
}

}