Xamarin Forms - просмотр в представлении списка прокрутки влево и вправо с использованием xamal

Question

Мне нужно написать код (или XAML) для viewview viewcell проведите пальцем влево и вправо.

При прокрутке влево удалите записи из списка listview (или наблюдаемой коллекции) и обновите оставшиеся списки в списке. При правильном прокрутке сохраните записи.

Answer 1

Я делаю это с помощью кода cs, вы можете попробовать его на xaml.

Во-первых, вы должны построить салфетки compoment используя жест

SwipeGestureGrid.cs

public class SwipeGestureGrid : Grid 
    { 
     #region Private Member 
     private double _gestureX { get; set; } 
     private double _gestureY { get; set; } 
     private bool IsSwipe { get; set; } 
     #endregion 
     #region Public Member 
     #region Events 
     #region Tapped 
     public event EventHandler Tapped; 
     protected void OnTapped(EventArgs e) 
     { 
      if (Tapped != null) 
       Tapped(this, e); 
     } 
     #endregion 
     #region SwipeUP 
     public event EventHandler SwipeUP; 
     protected void OnSwipeUP(EventArgs e) 
     { 
      if (SwipeUP != null) 
       SwipeUP(this, e); 
     } 
     #endregion 
     #region SwipeDown 
     public event EventHandler SwipeDown; 
     protected void OnSwipeDown(EventArgs e) 
     { 
      if (SwipeDown != null) 
       SwipeDown(this, e); 
     } 
     #endregion 
     #region SwipeRight 
     public event EventHandler SwipeRight; 
     protected void OnSwipeRight(EventArgs e) 
     { 
      if (SwipeRight != null) 
       SwipeRight(this, e); 
     } 
     #endregion 
     #region SwipeLeft 
     public event EventHandler SwipeLeft; 
     protected void OnSwipeLeft(EventArgs e) 
     { 
      if (SwipeLeft != null) 
       SwipeLeft(this, e); 
     } 
     #endregion 
     #endregion 
     public double Height 
     { 
      get 
      { 
       return HeightRequest; 
      } 
      set 
      { 
       HeightRequest = value; 
      } 
     } 
     public double Width 
     { 
      get 
      { 
       return WidthRequest; 
      } 
      set 
      { 
       WidthRequest = value; 
      } 
     } 
     #endregion 
     public SwipeGestureGrid() 
     { 
      PanGestureRecognizer panGesture = new PanGestureRecognizer(); 
      panGesture.PanUpdated += PanGesture_PanUpdated; 

      TapGestureRecognizer tapGesture = new TapGestureRecognizer(); 
      tapGesture.Tapped += TapGesture_Tapped; 

      GestureRecognizers.Add(panGesture); 
      GestureRecognizers.Add(tapGesture); 
     } 

     private void TapGesture_Tapped(object sender, EventArgs e) 
     { 
      try 
      { 
       if (!IsSwipe) 
        OnTapped(null); 

       IsSwipe = false; 
      } 
      catch (Exception ex) 
      { 

      } 
     } 

     private void PanGesture_PanUpdated(object sender, PanUpdatedEventArgs e) 
     { 
      try 
      { 
       switch (e.StatusType) 
       { 
        case GestureStatus.Running: 
         { 
          _gestureX = e.TotalX; 
          _gestureY = e.TotalY; 
         } 
         break; 
        case GestureStatus.Completed: 
         { 
          IsSwipe = true; 
          //Debug.WriteLine("{0} {1}", _gestureX, _gestureY); 
          if (Math.Abs(_gestureX) > Math.Abs(_gestureY)) 
          { 
           if (_gestureX > 0) 
           { 
            OnSwipeRight(null); 
           } 
           else 
           { 
            OnSwipeLeft(null); 
           } 
          } 
          else 
          { 
           if (_gestureY > 0) 
           { 
            OnSwipeDown(null); 
           } 
           else 
           { 
            OnSwipeUP(null); 
           } 
          } 
         } 
         break; 
       } 
      } 
      catch (Exception ex) 
      { 
      } 
     } 
    } 

Следующая используя DataTemplate в ListView andattach событие для Gesturecompoment

Page.cs

ListView lsvData = new ListView() 
     { 
      VerticalOptions = LayoutOptions.Fill, 
      HorizontalOptions = LayoutOptions.Fill, 
      BackgroundColor = Color.White, 
      HasUnevenRows = true, 
     }; 
     List<string> lstData = new List<string>(); 
     public Pages() 
     { 
      #region DataTemplate 
      DataTemplate ListDataTemplate = new DataTemplate(() => 
      { 
       #region DataArea of Template 
       SwipeGestureGrid gridData = new SwipeGestureGrid() 
       { 
        HorizontalOptions = LayoutOptions.FillAndExpand, 
        VerticalOptions = LayoutOptions.FillAndExpand, 
        HeightRequest = 60, 
        RowDefinitions = 
         { 
          new RowDefinition { }, 
         }, 
        ColumnDefinitions = 
         { 
          new ColumnDefinition { }, 
         } 
       }; 
       #endregion 
       #region Base of Template 
       Grid gridBase = new Grid() 
       { 
        HorizontalOptions = LayoutOptions.FillAndExpand, 
        VerticalOptions = LayoutOptions.FillAndExpand, 
        HeightRequest = 60, 
        RowDefinitions = 
        { 
         new RowDefinition { }, 
        }, 
        ColumnDefinitions = 
        { 
         new ColumnDefinition { },             //Put Cells Data here 
         new ColumnDefinition { Width = new GridLength(0, GridUnitType.Absolute)}, //Button for Cells here 
        }, 
       }; 
       #endregion 
       Label lblText = new Label 
       { 
        HorizontalOptions = LayoutOptions.FillAndExpand, 
        VerticalOptions = LayoutOptions.FillAndExpand, 
        FontAttributes = FontAttributes.Bold, 
        VerticalTextAlignment = TextAlignment.End, 
        TextColor = Color.Black, 
        BackgroundColor = Color.Silver, 
        LineBreakMode = LineBreakMode.TailTruncation, 
        FontSize = 18, 
       }; 
       lblText.SetBinding(Label.TextProperty, "."); 

       ImageButton btnCellDelete = new ImageButton() { Source = "Delete" }; 

       gridData.Children.Add(lblText, 0, 0); 

       gridBase.Children.Add(gridData, 0, 0); 
       gridBase.Children.Add(btnCellDelete, 1, 0); 

       gridData.SwipeLeft += GridTemplate_SwipeLeft; 
       gridData.SwipeRight += GridTemplate_SwipeRight; ; 
       gridData.Tapped += GridTemplate_Tapped; ; 
       btnCellDelete.Clicked += BtnCellDelete_Clicked; ; 

       return new ViewCell 
       { 
        View = gridBase, 
        Height = 60, 
       }; 
      }); 

      #endregion 
      for (int i = 1; i <= 100; i++) 
      { 
       lstData.Add(i.ToString()); 
      } 
      lsvData.ItemTemplate = ListDataTemplate; 
      lsvData.ItemsSource = lstData; 
      Content = lsvData; 
     } 

мероприятие

SwipeLeft показать кнопку удаления

private void GridTemplate_SwipeLeft(object sender, EventArgs e) 
    { 
     try 
     { 
      if (sender is SwipeGestureGrid) 
      { 
       var templateGrid = ((SwipeGestureGrid)sender).Parent; 
       if (templateGrid != null && templateGrid is Grid) 
       { 
        var CellTemplateGrid = (Grid)templateGrid; 
        CellTemplateGrid.ColumnDefinitions[1].Width = new GridLength(60, GridUnitType.Absolute); 
       } 
      } 

     } 
     catch (Exception ex) 
     { 

     } 
    } 

swiperight скрыть кнопку удаления

private void GridTemplate_SwipeRight(object sender, EventArgs e) 
    { 
     try 
     { 
      if (sender is SwipeGestureGrid) 
      { 
       var templateGrid = ((SwipeGestureGrid)sender).Parent; 
       if (templateGrid != null && templateGrid is Grid) 
       { 
        var CellTemplateGrid = (Grid)templateGrid; 
        CellTemplateGrid.ColumnDefinitions[1].Width = new GridLength(0, GridUnitType.Absolute); 
       } 
      } 
     } 
     catch (Exception ex) 
     { 

     } 
    } 

Кнопка удаления события нажатия

private void BtnCellDelete_Clicked(object sender, EventArgs e) 
    { 
     try 
     { 
      if (sender is ImageButton) 
      { 
       var templateGrid = ((ImageButton)sender); 
       //templateGrid.Parent = gridBase 
       //templateGrid.Parent.Parent = cell 
       if (templateGrid.Parent != null && templateGrid.Parent.Parent != null && templateGrid.Parent.Parent.BindingContext != null && templateGrid.Parent.Parent.BindingContext is string) 
       { 
        var deletedate = templateGrid.Parent.Parent.BindingContext as string; 
        lstData.RemoveAll(f => f == deletedate); 
        lsvData.ItemsSource = null; 
        lsvData.ItemsSource = lstData; 
       } 
      } 
     } 
     catch (Exception ex) 
     { 

     } 
    } 

Источник можно найти в моем GitHub https://github.com/act70255/ListViewSwipeGesture