添加到收藏按钮内的StackPanel

本文关键字：StackPanel 按钮 收藏 添加 | 更新日期: 2023-09-27 18:05:30

我有一个问题，我想不出如何解决它。

我需要在StackPanel中添加一个按钮到Favorites，问题是该按钮按在其他页面上，即StackPanel声明，我不能将按钮添加到它的孩子。所以，我有两个页面:主页。xaml和PlayerPage。xaml。

在MainPage我保持一个StackPanel与按钮，如:

<StackPanel x:Name="mainStack"  >
  <Button x:Name="but1" Click="Button2_Click" Tag="/videos/video1.mp4" Content="Play Video 1" />
  <Button x:Name="but2" Click="Button2_Click" Tag="/videos/video2.mp4" Content="Play Video 2" />
  <Button x:Name="but3" Click="Button2_Click" Tag="/videos/video3.mp4" Content="Play Video 3" />
</StackPanel>
<StackPanel x:Name="favoriteStack"  >
  <!-- Here need to be added favorite videos when user press Add to fav button! -->
</StackPanel>

cs 

private void Button2_Click(object sender, EventArgs e)
{
    NavigationService.Navigate(
        new Uri("/PlayerPage.xaml?path=" +
                HttpUtility.UrlEncode((sender as Button).Tag.ToString()),
                UriKind.Relative));
}
在PlayerPage

。xaml: 

<MediaElement x:Name="mediaElement1"
              MediaOpened="mediaElement1_MediaOpened"
              MediaFailed="mediaElement1_MediaFailed"
              MediaEnded="mediaElement1_MediaEnded"
              CurrentStateChanged="mediaElement1_CurrentStateChanged" />
<Button x:Name="AddToFav" Click="Button1_Click"
        Content="Add this video to Favorites" />

cs 

protected override void OnNavigatedTo(NavigationEventArgs e)
{
    if (NavigationContext.QueryString.TryGetValue("path", out path))
    {
        if (!string.IsNullOrWhiteSpace(path))
        {
            mediaElement1.Source = new Uri( path );
        }
    }
}
private void Button1_Click(object sender, RoutedEventArgs e)
{
    // here must be somethink like:
    Button butsender = new Button();
    butsender = sender as Button;
    stack2.Children.Add(butsender);
    //better will be to save to Isolated Storage or somethink like this for future launching...
}

我有很多问题，因为我真的不知道如何执行…我试过使用全局应用程序栏并分配更多，但没有成功。任何帮助将不胜感激!谢谢!

添加到收藏按钮内的StackPanel

执行此操作的最佳方法是遵循MVVM模式。您将定义一个包含两个列表的ViewModel类。

public class MainViewModel : INotifyPropertyChanged
{
    public ObservableCollection<Video> Videos { get; set; }
    public ObservableCollection<Video> FavoriteVideos { get; set; }
    public MainViewModel()
    {
        Videos = new ObservableCollection<Video>();
        FavoriteVideos = new ObservableCollection<Video>();
    }
    private Video selectedVideo;
    public Video SelectedVideo
    {
        get { return selectedVideo; }
        set { selectedVideo = value; NotifyPropertyChanged("SelectedVideo"); }
    }
    public event PropertyChangedEventHandler PropertyChanged;
    private void NotifyPropertyChanged(String propertyName)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (null != handler)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

在app . example .cs中你将定义ViewModel

private static MainViewModel viewModel = null;
    public static MainViewModel ViewModel
    {
        get
        {
            // Delay creation of the view model until necessary
            if (viewModel == null)
                viewModel = new MainViewModel();
            return viewModel;
        }
    }
然后你可以在构造函数中设置两个页面(MainPage和其他)的数据上下文，像这样: 
DataContext = App.ViewModel;

现在你只需要绑定项目到两个列表(StackPanel不会在这里做。使用其他列表，如ListBox)

ItemsSource="{Binding Videos}"
ItemsSource="{Biding FavoriteVideos}"

对于导航，如果你使用ListBox，只需设置点击事件

ItemClick="ItemClick"

private void ItemClick(object sender, ItemClickEventArgs e)
{
        Video item = e.ClickedItem as Video;
        App.ViewModel.SelectedVideo = item;
        NavigationService.Navigate(new Uri("/PlayerPage.xaml,UriKind.Relative));
}

在PlayerPage上绑定到SelectedVideo就可以了。对于收藏，你只需要将视频添加到FavoriteList

private void FavoriteButton_Click(object sender, RoutedEventArgs e)
{
     if(!App.ViewModel.FavoriteVideos.Contains(App.ViewModel.SelectedVideo)) {
         App.ViewModel.FavoriteVideos.Add(App.ViewModel.SelectedVideo);
     }
}

现在你可以根据需要在应用中动态添加数据。StackPanel只会帮助你的静态视频，如果数据发生变化，它是不实用的。

相关文章：