Wpf 选项卡在DataGrid中创建新行并聚焦新行

我的数据网格有一些问题。我的项目正在将一个Delphi项目转换为.Net。产品所有者希望datagrids具有相同的行为

当定位到最后一个单元格并点击tab或enter时，应发生以下情况：

将添加一个新行

将选中新行中的第一个单元格

datagrid的其他需求包括：

• 一旦有了焦点，焦点就应该留在数据网格内（ALT+组合键是再次离开数据网格的方式）
• 数据网格是数据绑定的
• 数据网格用于MVVM
• 我们使用.net4.0完整配置文件
有我能找到的最好的解决方案
我更喜欢使用附加属性而不是行为，因为这使我能够轻松地将其设置为

DataGrid

的默认样式。代码如下：

namespace SampleDataGridApp
{
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Input;

    /// <summary>
    /// An attached behavior that modifies the tab behavior for a <see cref="DataGrid"/>.
    /// </summary>
    public static class DataGridBehavior
    {
        /// <summary>
        /// Identifies the <c>NewLineOnTab</c> attached property.
        /// </summary>
        public static readonly DependencyProperty NewLineOnTabProperty = DependencyProperty.RegisterAttached(
            "NewLineOnTab",
            typeof(bool),
            typeof(DataGridBehavior),
            new PropertyMetadata(default(bool), OnNewLineOnTabChanged));

        /// <summary>
        /// Sets the value of the <c>NewLineOnTab</c> attached property.
        /// </summary>
        /// <param name="element">The <see cref="DataGrid"/>.</param>
        /// <param name="value">A value indicating whether to apply the behavior.</param>
        public static void SetNewLineOnTab(DataGrid element, bool value)
        {
            element.SetValue(NewLineOnTabProperty, value);
        }

        /// <summary>
        /// Gets the value of the <c>NewLineOnTab</c> attached property.
        /// </summary>
        /// <param name="element">The <see cref="DataGrid"/>.</param>
        /// <returns>A value indicating whether to apply the behavior.</returns>
        public static bool GetNewLineOnTab(DataGrid element)
        {
            return (bool)element.GetValue(NewLineOnTabProperty);
        }

        /// <summary>
        /// Called when the value of the <c>NewLineOnTab</c> property changes.
        /// </summary>
        /// <param name="sender">The event sender.</param>
        /// <param name="e">The event arguments.</param>
        private static void OnNewLineOnTabChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
        {
            DataGrid d = sender as DataGrid;

            if (d == null)
            {
                return;
            }

            bool newValue = (bool)e.NewValue;
            bool oldValue = (bool)e.OldValue;

            if (oldValue == newValue)
            {
                return;
            }

            if (oldValue)
            {
                d.PreviewKeyDown -= AssociatedObjectKeyDown;
            }
            else
            {
                d.PreviewKeyDown += AssociatedObjectKeyDown;
                KeyboardNavigation.SetTabNavigation(d, KeyboardNavigationMode.Contained);
            }
        }

        /// <summary>
        /// Handles the <see cref="UIElement.KeyDown"/> event for a <see cref="DataGridCell"/>.
        /// </summary>
        /// <param name="sender">The event sender.</param>
        /// <param name="e">The event arguments.</param>
        private static void AssociatedObjectKeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key != Key.Tab)
            {
                return;
            }

            DataGrid dg = e.Source as DataGrid;

            if (dg == null)
            {
                return;
            }

            if (dg.CurrentColumn.DisplayIndex == dg.Columns.Count - 1)
            {
                var icg = dg.ItemContainerGenerator;

                if (dg.SelectedIndex == icg.Items.Count - 2)
                {
                    dg.CommitEdit(DataGridEditingUnit.Row, false);
                }
            }
        }
    }
}

---

好的，我已经和这个问题斗争了好几个小时了。我已经尝试了几乎每一个提议的解决方案，这里是我发现对我有用的

    private void grid_PreviewKeyDown(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Tab)
        {
            if (grid.SelectedIndex == grid.Items.Count - 2 && grid.CurrentColumn.DisplayIndex == grid.Columns.Count - 1)
            {
                grid.CommitEdit(DataGridEditingUnit.Row, false);
                e.Handled = true;
            }
        }
    }

    private void DataGrid_RowEditEnding(object sender, DataGridRowEditEndingEventArgs e)
    {
        if (grid.SelectedIndex == grid.Items.Count - 2)
        {
            grid.SelectedIndex = grid.Items.Count - 1;
            grid.CurrentCell = new DataGridCellInfo(grid.Items[grid.Items.Count - 1], grid.Columns[0]);
        }
    }

此代码的作用是，当您在最后一行的最后一个单元格上按tab键时，它会将焦点移动到新行的第一个单元格。这是您所期望的，但这不是默认行为。默认行为是将焦点移动到下一个控件，而不是提交当前行编辑。这显然是DataGrid中的一个bug，我相信这就是为什么所有建议的解决方案都有一点kluge的味道。我承认我的解决方案闻起来不太好，但如果你同意这是bug，我更喜欢这一点，而不是荒谬的默认行为
即使网格已排序，此解决方案也可以工作。新输入的行将排序到正确的位置，但焦点将放在新行的第一列

---

唯一未解决的问题是，当从顶部向下切换到新行之前的最后一个单元格时，必须在焦点移动到新行之前输入两次tab。我研究了一下这个怪癖，最后放弃了。
我试过摆弄KeyboardNavigation.TabNavigation=“Contained”和KeyboardNavigation.TabNavigation的其他值。我似乎找不到一个组合。我的所有尝试要么从数据网格中删除选项卡，要么不创建新行。在我看来，我需要一些其他技术来调整datagrid，但我还没有找到。

private static void AssociatedObjectKeyDown(object sender, KeyEventArgs e)
{               
    if (e.Key != Key.Tab)
    {
        return;
    }

    DataGrid dg = e.Source as DataGrid;

    if (dg == null)
    {
        return;
    }

    int offSet = 1;
    var columnsReversed = dg.Columns.Reverse();
    foreach (var dataGridColumn in columnsReversed)
    {
        // Bug: This makes the grand assumption that a readonly column's "DataGridCell" has IsTabStop == false;
        if (dataGridColumn.IsReadOnly)
        {
            offSet++;
        }
        else
        {
            break;
        }
    }

    if (dg.CurrentColumn.DisplayIndex == (dg.Columns.Count - offSet))
    {
        var icg = dg.ItemContainerGenerator;

        if (dg.SelectedIndex == icg.Items.Count - 2)
        {
            dg.CommitEdit(DataGridEditingUnit.Row, false);
        }
    }
}

    private void grid_PreviewKeyDown(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Tab)
        {
            if (grid.SelectedIndex == grid.Items.Count - 2 && grid.CurrentColumn.DisplayIndex == grid.Columns.Count - 1)
            {
                grid.CommitEdit(DataGridEditingUnit.Row, false);
                e.Handled = true;
            }
        }
    }

    private void DataGrid_RowEditEnding(object sender, DataGridRowEditEndingEventArgs e)
    {
        if (grid.SelectedIndex == grid.Items.Count - 2)
        {
            grid.SelectedIndex = grid.Items.Count - 1;
            grid.CurrentCell = new DataGridCellInfo(grid.Items[grid.Items.Count - 1], grid.Columns[0]);
        }
    }