如何刪除數據網格上的多個選定的行

Question

我有一個數據網格顯示SQL數據庫表中存在的所有記錄，我想添加一個按鈕到我的用戶界面，允許用戶刪除記錄）他或她選擇了。我發現的大多數參考文獻都是圍繞每行添加一個刪除按鈕或者涉及代碼。我正在使用MVVM模式，我不想在每一行中都有一個按鈕。目前，我可以一次刪除一條記錄，但需要有關如何遍歷所選項目的幫助。我的代碼如下：

XAML

  <Button x:Name="revokeBtn" 
       Grid.Row="0" 
       Grid.Column="4" 
       ToolTip="Revoke Selected License or Licenses" 
       Content="Revoke" 
       Command="{Binding RevokeSelectedCommand}" 
       CommandParameter="{Binding}"> 
     </Button> 

     <DataGrid x:Name="licenseGrid" 
        ItemsSource="{Binding LoggedUsers}" 
        SelectedItem="{Binding SelectedLicenses}" 
        Style="{DynamicResource DataGridStyle}" 
        Grid.Row="2" 
        Grid.Column="1" 
        Grid.ColumnSpan="6" 
        Height="535" 
        VerticalAlignment="Top" 
        IsReadOnly="True" 
        AutoGenerateColumns="False" 
        HeadersVisibility="Column" 
        SelectionMode="Extended" 
        CanUserDeleteRows="True" 
        EnableRowVirtualization="False"> 
      <DataGrid.RowStyle> 
       <Style TargetType="DataGridRow"> 
        <Setter Property="IsSelected" Value="{Binding IsSelected}" /> 
       </Style> 
      </DataGrid.RowStyle> 

與被綁定到表列DataGrid.Columns。

視圖模型

public ObservableCollection<MD_LoggedUsersModel> LoggedUsers 
    { 
     get { return _loggedUsers; } 
     set { _loggedUsers = value; NotifyPropertyChanged(nameof(LoggedUsers)); } 
    } 

    public MD_LoggedUsersModel SelectedLicenses 
    { 
     get 
     { 
      return _selectedLicenses; 
     } 
     set 
     { 
      if (_selectedLicenses != value) 
      { 
       _selectedLicenses = value; 
       OnPropertyChanged(nameof(SelectedLicenses)); 
      } 
      if (_selectedLicenses == null) 
      { 
       LoadData(); 
      } 
     } 
    } 

    public bool IsSelected 
    { 
     get 
     { 
      return _isSelected; 
     } 
     set 
     { 
      if (_isSelected == value) return; 
      _isSelected = value; 
      OnPropertyChanged(nameof(IsSelected)); 
     } 
    } 

    public ICommand RevokeSelectedCommand 
    { 
     get 
     { 
      return _revokeSelectedCommand ?? (_revokeSelectedCommand = new CommandHandler(() => RevokeSelected(), _canExecute)); 
     } 
    } 
    private void RevokeSelected() 
    {need to iterate through selected rows here} 

什麼是實現這一目標的最佳方式是什麼？

Answer 1

由於缺乏對這篇文章的迴應以及缺乏資源，我可以在這個問題上找到答案，我選擇了正確工作的每一行中的按鈕。

Answer 2

我已經有這個問題，一對夫婦一個月前的爲此和我寫了下面的附加屬性：

public class MultiSelectorExtensions 
    { 
     public static readonly DependencyProperty SelectedItemsProperty = DependencyProperty.RegisterAttached(
      "SelectedItems", 
      typeof(INotifyCollectionChanged), 
      typeof(MultiSelectorExtensions), 
      new PropertyMetadata(default(INotifyCollectionChanged), OnSelectedItemsChanged)); 

     private static void OnSelectedItemsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) 
     { 
      MultiSelector multiSelectorControl = d as MultiSelector; 

      NotifyCollectionChangedEventHandler handler = (sender, args) => 
      { 
       if (multiSelectorControl != null) 
       { 
        IList listSelectedItems = multiSelectorControl.SelectedItems; 
        if (args.OldItems != null) 
        { 
         foreach (var item in args.OldItems) 
         { 
          if (listSelectedItems.Contains(item)) 
           listSelectedItems.Remove(item); 
         } 
        } 

        if (args.NewItems != null) 
        { 
         foreach (var item in args.NewItems) 
         { 
          if (!listSelectedItems.Contains(item)) 
           listSelectedItems.Add(item); 
         } 
        } 
       } 
      }; 

      if (e.OldValue == null && multiSelectorControl != null) 
      { 
       multiSelectorControl.SelectionChanged += OnSelectionChanged; 
      } 

      if (e.OldValue is INotifyCollectionChanged) 
      { 
       (e.OldValue as INotifyCollectionChanged).CollectionChanged -= handler; 
      } 

      if (e.NewValue is INotifyCollectionChanged) 
      { 
       (e.NewValue as INotifyCollectionChanged).CollectionChanged += handler; 
      } 

     } 

     private static void OnSelectionChanged(object sender, SelectionChangedEventArgs e) 
     { 
      DependencyObject d = sender as DependencyObject; 

      if (GetSelectionChangedInProgress(d)) 
       return; 

      SetSelectionChangedInProgress(d, true); 

      dynamic selectedItems = GetSelectedItems(d); 

      try 
      { 
       foreach (dynamic item in e.RemovedItems.Cast<dynamic>().Where(item => selectedItems.Contains(item))) 
       { 
        selectedItems.Remove(item); 
       } 
      } 
      catch (Exception) { } 

      try 
      { 
       foreach (dynamic item in e.AddedItems.Cast<dynamic>().Where(item => !selectedItems.Contains(item))) 
       { 
        selectedItems.Add(item); 
       } 
      } 
      catch (Exception){} 

      SetSelectionChangedInProgress(d, false); 
     } 

     public static void SetSelectedItems(DependencyObject element, INotifyCollectionChanged value) 
     { 
      element.SetValue(SelectedItemsProperty, value); 
     } 

     public static INotifyCollectionChanged GetSelectedItems(DependencyObject element) 
     { 
      return (INotifyCollectionChanged)element.GetValue(SelectedItemsProperty); 
     } 

     private static readonly DependencyProperty SelectionChangedInProgressProperty = DependencyProperty.RegisterAttached(
      "SelectionChangedInProgress", 
      typeof(bool), 
      typeof(MultiSelectorExtensions), 
      new PropertyMetadata(default(bool))); 

     private static void SetSelectionChangedInProgress(DependencyObject element, bool value) 
     { 
      element.SetValue(SelectionChangedInProgressProperty, value); 
     } 

     private static bool GetSelectionChangedInProgress(DependencyObject element) 
     { 
      return (bool)element.GetValue(SelectionChangedInProgressProperty); 
     } 
    } 

在視圖您DataGrid你將不得不使用這種附加屬性類似：

<DataGrid x:Name="licenseGrid" 
      ItemsSource="{Binding LoggedUsers}" 
      SelectedItem="{Binding SelectedLicenses}" 
      Style="{DynamicResource DataGridStyle}" 
      Grid.Row="2" 
      Grid.Column="1" 
      Grid.ColumnSpan="6" 
      Height="535" 
      VerticalAlignment="Top" 
      IsReadOnly="True" 
      AutoGenerateColumns="False" 
      HeadersVisibility="Column" 
      SelectionMode="Extended" 
      CanUserDeleteRows="True" 
      EnableRowVirtualization="False" 
      MyAttachedProperties:MultiSelectorExtensions.SelectedItems="{Binding SelectedLoggedUsers, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"></DataGrid> 

MyAttachedProperties是在MultiSelectorExtension類所在的命名空間。

並在您的視圖模型，你再有它看起來像一個屬性：

private ObservableCollection<MD_LoggedUsersModel> selectedLoggedUsers; 
public ObservableCollection<MD_LoggedUsersModel> SelectedLoggedUsers 
{ 
    get { return selectedLoggedUsers; } 
    set 
    { 
     selectedLoggedUsers = value; 
     NotifyPropertyChanged(nameof(SelectedLoggedUsers)); 
    } 
} 

重要提示：在您的視圖模型的構造函數，你必須初始化SelectedLoggedUsers與

SelectedLoggedUsers = new ObservableCollection<MD_LoggedUsersModel>(); 

否則酒店將爲空並且附加屬性不起作用。