Xamarin forms Prism - 从网格到内容页面的导航。页面未显示

Question

在 ContentPage 中，我在 ListView 中有一个 "rooms" 的列表。当我单击其中一个时，它应该导航到另一个包含房间详细信息的 ContentPage。新页面的 ViewModel 上的 OnNavigatedTo() 被调用（显然没有错误），但页面没有显示。它留在房间列表的页面中。我用 Android（模拟器和 phone）和 Visual Studio 2015 测试它。

这里是列表页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:prism="clr-namespace:Prism.Mvvm;assembly=Prism.Forms"
             xmlns:views="clr-namespace:StudentRooms.Views;assembly=StudentRooms"
             prism:ViewModelLocator.AutowireViewModel="True"
             x:Class="StudentRooms.Views.RoomsList">

  <StackLayout Orientation="Vertical">
    <ListView ItemsSource="{Binding Rooms}"
              >
      <ListView.ItemTemplate>
        <DataTemplate>
          <ViewCell>
            <StackLayout Orientation="Horizontal" Spacing="10">

              <StackLayout.GestureRecognizers>
                <TapGestureRecognizer CommandParameter="{Binding Id}" 
                                      Command="{Binding BindingContext.RoomSelected, Source={views:RoomsList}}">
                </TapGestureRecognizer>
              </StackLayout.GestureRecognizers>

              <Label Text="{Binding Name}" FontAttributes="Bold"/>
              <Label Text="{Binding Description}"></Label>
              <ProgressBar Progress="{Binding Occupancy}"/>
            </StackLayout>
          </ViewCell>
        </DataTemplate>
      </ListView.ItemTemplate>
    </ListView>  
  </StackLayout>

</ContentPage>

这里是 ViewModel 的片段：

public RoomsListViewModel(INavigationService navigationService)
{
    _navigationService = navigationService;

    RoomSelected = new DelegateCommand<object>(NavigateToSelectedRoom);
}

private void NavigateToSelectedRoom(object id)
{
    //var navParams = new NavigationParameters
    //{
    //    { "RoomId", id }
    //};

    //_navigationService.NavigateAsync("RoomDetail", navParams);

    _navigationService.NavigateAsync("RoomDetail");
}

详情页：

<?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:prism="clr-namespace:Prism.Mvvm;assembly=Prism.Forms"
             prism:ViewModelLocator.AutowireViewModel="True"
             x:Class="StudentRooms.Views.RoomDetail">

  <StackLayout>
    <Label Text="AAA"></Label>
  </StackLayout>
</ContentPage>

ViewModel 的片段：

public void OnNavigatedTo(NavigationParameters parameters)
{
    // on Debug I enter in this method!
}

Answer 1

确保在您的应用程序中注册用于导航的页面。cs/App。xaml.cs 文件。

Xamarin forms Prism - 从网格到内容页面的导航。页面未显示

Xamarin forms Prism - Navigation from grid to content page. Page not shown

c#

prism

xamarin.forms