DataGridComboBoxColumn - Auto a discesa con un solo clic

Question

Ho un DataGridComboBoxColum in un DataGrid. Vorrei poter fare clic sulla cella una volta e avere la casella combinata a discesa. Attualmente devo fare clic più volte.

<DataGrid AutoGenerateColumns="False" Height="148" HorizontalAlignment="Left" Margin="48,85,0,0" Name ="dg_display" VerticalAlignment="Top" Width="645" CanUserAddRows="False" CanUserDeleteRows="False" ItemsSource="{Binding}" SelectionChanged="DgDisplaySelectionChanged"> 
     <DataGrid.Columns> 
      <DataGridTextColumn IsReadOnly="True" Header="Symbol" Binding="{Binding Symbol}" /> 
      <DataGridTextColumn IsReadOnly="True" Header="Company ID" Binding="{Binding CompanyID}" /> 
      <DataGridComboBoxColumn IsReadOnly="False" Header="Sector" SelectedValueBinding="{Binding Sector}" DisplayMemberPath="{Binding [0]}" Visibility="Visible" > 
       <DataGridComboBoxColumn.EditingElementStyle> 
        <Style TargetType="ComboBox"> 
         <Setter Property="ItemsSource" Value="{Binding SectorList}" /> 
        </Style> 
       </DataGridComboBoxColumn.EditingElementStyle> 
       <DataGridComboBoxColumn.ElementStyle> 
        <Style TargetType="ComboBox"> 
         <Setter Property="ItemsSource" Value="{Binding SectorList}" /> 
        </Style> 
       </DataGridComboBoxColumn.ElementStyle> 
      </DataGridComboBoxColumn> 
     </DataGrid.Columns> 
    </DataGrid> 

Answer 1

One-click DataGridComboBoxColumn editing + uno scatto editing CheckboxColumn
Vedi anche: https://stackoverflow.com/a/8333704/724944

XAML:

 <Style TargetType="{x:Type DataGridCell}"> 
      <EventSetter Event="PreviewMouseLeftButtonDown" Handler="DataGridCell_PreviewMouseLeftButtonDown" /> 
      <EventSetter Event="PreviewTextInput" Handler="DataGridCell_PreviewTextInput" /> 
     </Style> 

Codice-behind:

private void DataGridCell_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e) 
    { 
     DataGridCell cell = sender as DataGridCell; 
     GridColumnFastEdit(cell, e); 
    } 

    private void DataGridCell_PreviewTextInput(object sender, TextCompositionEventArgs e) 
    { 
     DataGridCell cell = sender as DataGridCell; 
     GridColumnFastEdit(cell, e); 
    } 

    private static void GridColumnFastEdit(DataGridCell cell, RoutedEventArgs e) 
    { 
     if (cell == null || cell.IsEditing || cell.IsReadOnly) 
      return; 

     DataGrid dataGrid = FindVisualParent<DataGrid>(cell); 
     if (dataGrid == null) 
      return; 

     if (!cell.IsFocused) 
     { 
      cell.Focus(); 
     } 

     if (cell.Content is CheckBox) 
     { 
      if (dataGrid.SelectionUnit != DataGridSelectionUnit.FullRow) 
      { 
       if (!cell.IsSelected) 
        cell.IsSelected = true; 
      } 
      else 
      { 
       DataGridRow row = FindVisualParent<DataGridRow>(cell); 
       if (row != null && !row.IsSelected) 
       { 
        row.IsSelected = true; 
       } 
      } 
     } 
     else 
     { 
      ComboBox cb = cell.Content as ComboBox; 
      if (cb != null) 
      { 
       //DataGrid dataGrid = FindVisualParent<DataGrid>(cell); 
       dataGrid.BeginEdit(e); 
       cell.Dispatcher.Invoke(
       DispatcherPriority.Background, 
       new Action(delegate { })); 
       cb.IsDropDownOpen = true; 
      } 
     } 
    } 


    private static T FindVisualParent<T>(UIElement element) where T : UIElement 
    { 
     UIElement parent = element; 
     while (parent != null) 
     { 
      T correctlyTyped = parent as T; 
      if (correctlyTyped != null) 
      { 
       return correctlyTyped; 
      } 

      parent = VisualTreeHelper.GetParent(parent) as UIElement; 
     } 
     return null; 
    } 

Answer 2

ho avuto problemi con @su la risposta di rfen, probabilmente perché sono passati molti anni e il WPF probabilmente è cambiato parecchio. Sembra che DataGrid ora si prenda cura di alcune cose per te, come la modifica di un campo di testo automaticamente quando inizi a digitare.

Io uso un DataGridTemplateColumn per la mia colonna casella combinata. Il modello ha un TextBlock per il suo CellTemplate. La chiamata a BeginEdit seguita dalla chiamata del dispatcher fa apparire la casella combinata nell'albero visivo. Sembra quindi che il clic del mouse venga inviato alla casella combinata e si apra da solo.

Ecco la mia versione modificata del @ di surfen codice:

public static class DataGridExtensions 
{ 
    public static void FastEdit(this DataGrid dataGrid) 
    { 
     dataGrid.ThrowIfNull(nameof(dataGrid)); 

     dataGrid.PreviewMouseLeftButtonDown += (sender, args) => { FastEdit(args.OriginalSource, args); }; 
    } 

    private static void FastEdit(object source, RoutedEventArgs args) 
    { 
     var dataGridCell = (source as UIElement)?.FindVisualParent<DataGridCell>(); 

     if (dataGridCell == null || dataGridCell.IsEditing || dataGridCell.IsReadOnly) 
     { 
      return; 
     } 

     var dataGrid = dataGridCell.FindVisualParent<DataGrid>(); 

     if (dataGrid == null) 
     { 
      return; 
     } 

     if (!dataGridCell.IsFocused) 
     { 
      dataGridCell.Focus(); 
     } 

     if (dataGridCell.Content is CheckBox) 
     { 
      if (dataGrid.SelectionUnit != DataGridSelectionUnit.FullRow) 
      { 
       if (!dataGridCell.IsSelected) 
       { 
        dataGridCell.IsSelected = true; 
       } 
      } 
      else 
      { 
       var dataGridRow = dataGridCell.FindVisualParent<DataGridRow>(); 

       if (dataGridRow != null && !dataGridRow.IsSelected) 
       { 
        dataGridRow.IsSelected = true; 
       } 
      } 
     } 
     else 
     { 
      dataGrid.BeginEdit(args); 

      dataGridCell.Dispatcher.Invoke(DispatcherPriority.Background, new Action(() => { })); 
     } 
    } 
} 

public static class UIElementExtensions 
{ 
    public static T FindVisualParent<T>(this UIElement element) 
     where T : UIElement 
    { 
     UIElement currentElement = element; 

     while (currentElement != null) 
     { 
      var correctlyTyped = currentElement as T; 

      if (correctlyTyped != null) 
      { 
       return correctlyTyped; 
      } 

      currentElement = VisualTreeHelper.GetParent(currentElement) as UIElement; 
     } 

     return null; 
    } 
}