在WPF DataGrid中按Enter键时将焦点移动到下一个单元格？

Question

我想要一个自定义的DataGrid，可以，

1. 如果处于编辑模式，按下 Enter 键时移动到下一个单元格。
2. 到达当前行的最后一列时，焦点应移至下一行的第一个单元格。
3. 到达下一个单元格时，如果该单元格是可编辑的，它应该会自动变为可编辑。
4. 如果单元格包含 ComboBox 而不是组合框列，则组合框应 DropDownOpen。​​

请帮助我。从过去的几天开始，我一直在尝试创建一个自定义 DataGrid 并在

中编写了一些代码

protected override void OnPreviewKeyDown(System.Windows.Input.KeyEventArgs e)

但我失败了。

Answer 1

一个更简单的实现。这个想法是捕获 keydown 事件，如果键是“Enter”，则移动到下一个选项卡，即网格的下一个单元格。

/// <summary>
/// On Enter Key, it tabs to into next cell.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void DataGrid_OnPreviewKeyDown(object sender, KeyEventArgs e)
{
    var uiElement = e.OriginalSource as UIElement;
    if (e.Key == Key.Enter && uiElement != null)
    {
        e.Handled = true;
        uiElement.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
    }
}

Answer 2

private void dg_PreviewKeyDown(object sender, KeyEventArgs e)
{
    try
    {
        if (e.Key == Key.Enter)
        {
            e.Handled = true;
            var cell = GetCell(dgIssuance, dgIssuance.Items.Count - 1, 2);
            if (cell != null)
            {
                cell.IsSelected = true;
                cell.Focus();
                dg.BeginEdit();
            }
        }
    }
    catch (Exception ex)
    {
        MessageBox(ex.Message, "Error", MessageType.Error);
    }
}  

public static DataGridCell GetCell(DataGrid dg, int row, int column)
{
    var rowContainer = GetRow(dg, row);

    if (rowContainer != null)
    {
        var presenter = GetVisualChild<DataGridCellsPresenter>(rowContainer);
        if (presenter != null)
        {
            // try to get the cell but it may possibly be virtualized
            var cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
            if (cell == null)
            {
                // now try to bring into view and retreive the cell
                dg.ScrollIntoView(rowContainer, dg.Columns[column]);
                cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
            }
            return cell;
        }
    }
    return null;
}

Answer 3

这个解决方案怎么样？通过设置Handled=true取消Enter键的动作并按下Tab键。

public Constructor()
{
  InitializeComponent(); 
  this.SampleDataGrid.PreviewKeyDown += MoveCellOnEnterKey;
}

private void MoveCellOnEnterKey(object sender, KeyEventArgs e)
{
  if(e.Key == Key.Enter)
  {
    // Cancel [Enter] key event.
    e.Handled = true;
    // Press [Tab] key programatically.
    var tabKeyEvent = new KeyEventArgs(
      e.KeyboardDevice, e.InputSource, e.Timestamp, Key.Tab);
    tabKeyEvent.RoutedEvent = Keyboard.KeyDownEvent;
    InputManager.Current.ProcessInput(tabKeyEvent);
  }
}

Answer 4

public class DataGrid : System.Windows.Controls.DataGrid
{
    private void PressKey(Key key)
    {
        KeyEventArgs args = new KeyEventArgs(Keyboard.PrimaryDevice, Keyboard.PrimaryDevice.ActiveSource, 0, key);
        args.RoutedEvent = Keyboard.KeyDownEvent;
        InputManager.Current.ProcessInput(args);
    }
    protected override void OnCurrentCellChanged(EventArgs e)
    {
        if (this.CurrentCell.Column != null)                
            if (this.CurrentCell.Column.DisplayIndex == 2)
            {

                if (this.CurrentCell.Item.ToString() == "--End Of List--")
                {
                    this.MoveFocus(new TraversalRequest(FocusNavigationDirection.Down));
                }
            }
            else if (this.CurrentCell.Column != null && this.CurrentCell.Column.DisplayIndex == this.Columns.Count() - 1)
            {
                PressKey(Key.Return);
                DataGridCell cell = DataGridHelper.GetCell(this.CurrentCell);
                int index = DataGridHelper.GetRowIndex(cell);
                DataGridRow dgrow = (DataGridRow)this.ItemContainerGenerator.ContainerFromItem(this.Items[index]);
                dgrow.MoveFocus(new TraversalRequest(FocusNavigationDirection.First));
            }
    }
    protected override void OnKeyDown(KeyEventArgs e)
    {
        if (e.Key == Key.Enter)
        {
            DataGridRow rowContainer = (DataGridRow)this.ItemContainerGenerator.ContainerFromItem(this.CurrentItem);
            if (rowContainer != null)
            {
                int columnIndex = this.Columns.IndexOf(this.CurrentColumn);
                DataGridCellsPresenter presenter = UIHelper.GetVisualChild<DataGridCellsPresenter>(rowContainer);
                if (columnIndex == 0)
                {
                    DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(columnIndex);
                    TraversalRequest request = new TraversalRequest(FocusNavigationDirection.Next);
                    request.Wrapped = true;
                    cell.MoveFocus(request);
                    BeginEdit();
                    PressKey(Key.Down);
                }
                else
                {
                    CommitEdit();
                    DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(columnIndex);
                    TraversalRequest request = new TraversalRequest(FocusNavigationDirection.Next);
                    request.Wrapped = true;
                    cell.MoveFocus(request);
                }
                this.SelectedItem = this.CurrentItem;
                e.Handled = true;
                this.UpdateLayout();
            }
        }
    }
}

目前，我已经写了这个并且它为我工作。

Answer 5

    Public Sub SendKey(ByVal key As Key)
     Dim args As New KeyEventArgs(Keyboard.PrimaryDevice, Keyboard.PrimaryDevice.ActiveSource, 0, key)
        args.RoutedEvent = Keyboard.KeyDownEvent
        InputManager.Current.ProcessInput(args)
    End Sub
Private Sub dataGrid_PreviewKeyDown(sender As Object, e As KeyEventArgs) Handles dataGrid.PreviewKeyDown
        Dim i As UIElement = e.OriginalSource
        Dim DG As DataGrid = sender
        If (e.Key = Key.Enter Or e.Key = Key.Return) AndAlso i IsNot Nothing Then
            MyBase.OnKeyDown(e)
            DG.CommitEdit()
            SendKey(Key.Tab)
            e.Handled = True
        End If
    End Sub