我想在用戶更改頁面時從flipview中刪除項目。有什麼我可以做的嗎？

Question

我的要求是，我在我的應用程序中使用了一個flipview並動態地添加頁面。我想要這樣做，當我點擊addpages按鈕時，我的當前頁面從flipview中移除並且新頁面出現。我對addpage

public void Add_Pages_Click(object sender, RoutedEventArgs e) 
    { 
     try 
     { 

      my_canvas = new Canvas(); 
      my_canvas.Name = "Item" + DateTime.Now.ToFileTime().ToString(); 
      //fp1.ItemsSource = fi; 
      fp1.Items.Add(my_canvas); 
      fp1.SelectionChanged += Fp1_SelectionChanged; 
      Stickers1.Visibility = Visibility.Collapsed; 
      Backgrounds1.Visibility = Visibility.Collapsed; 
      Popup_wordart.IsOpen = false; 
      PopUp_Media.IsOpen = false; 
      my_canvas.Visibility = Visibility.Collapsed; 
      Audio_Recorder.IsOpen = false; 
     } 
     catch (Exception ex) 
     { 


     } 
     // Backward_Arrow.Visibility = Visibility.Visible; 
    } 

Answer 1

一個非常convenoent的方式來做好這項工作的代碼是建立在DataTemplate結構爲FlipView的每個項目，然後只用ObservableCollection添加，刪除，刷新FlipView的項目。

<FlipView x:Name="flipView" ItemsSource="{x:Bind flipviewCollection}"> 
    <FlipView.ItemTemplate> 
     <DataTemplate> 
      <Canvas> 
       <Image Source="{Binding ImageSource}" Stretch="None"/> 
      </Canvas> 
     </DataTemplate> 
    </FlipView.ItemTemplate> 
</FlipView> 

定義的數據模型，你需要在DataTemplate綁定：在你FlipView後面的代碼

public class ImageSourceClass 
{ 
    public string ImageSource { get; set; } 
} 

然後，創建這個數據模型的數據收集和添加到此集合：

ObservableCollection<ImageSourceClass> flipviewCollection = new ObservableCollection<ImageSourceClass>(); 

protected override void OnNavigatedTo(NavigationEventArgs e) 
{ 
    flipviewCollection.Clear(); 
    flipviewCollection.Add(new ImageSourceClass { ImageSource = "Assets/1.jpg" }); 
    flipviewCollection.Add(new ImageSourceClass { ImageSource = "Assets/2.jpg" }); 
    flipviewCollection.Add(new ImageSourceClass { ImageSource = "Assets/3.jpg" }); 
    flipviewCollection.Add(new ImageSourceClass { ImageSource = "Assets/4.jpg" }); 
    flipviewCollection.Add(new ImageSourceClass { ImageSource = "Assets/5.jpg" }); 
} 

最後，如果你想刪除的項目，並添加按鈕單擊事件一個新問題：

private void Button_Click(object sender, RoutedEventArgs e) 
{ 
    //index = flipView.SelectedIndex + 1 because when remove one item, next item will be shown, 
    //it will behavior like a new item replace the old one. 
    flipviewCollection.Insert(flipView.SelectedIndex + 1, new ImageSourceClass { ImageSource = "Assets/new.jpg" }); 
    flipviewCollection.Remove(flipView.SelectedItem as ImageSourceClass);         
} 

問題是，如果你沒有使用這種方法來建立一個FlipView，你只需將商品加入FlipView手動，您還需要去掉manully一個像你的代碼只是舉例這裏：

private void Button_Click(object sender, RoutedEventArgs e) 
{ 
    var my_canvas = new Canvas(); 
    var textbox = new TextBox(); 
    my_canvas.Children.Add(textbox); 
    flipView.Items.Insert(flipView.SelectedIndex + 1, my_canvas); 
    flipView.Items.RemoveAt(flipView.SelectedIndex);    
}