WPF - 在DataGridRow上设置IsSelected不会更改绑定对象

Question

我遇到的问题是我尝试使用具有多项选择功能的DataGrid，并且我试图在不按Ctrl键的情况下选择多个

在我看来，我有：

<DataGrid Grid.Row="1" ItemsSource="{Binding Tags}" SelectionMode="Extended" SelectionUnit="FullRow" AutoGenerateColumns="False"
                                   SelectedRows ="{Binding SelectedTags, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
                                   CanUserAddRows="False">

        <DataGrid.ItemContainerStyle>
            <Style TargetType="{x:Type DataGridRow}">
                <Setter Property="IsSelected" Value="{Binding IsSelected}"/>
            </Style>
        </DataGrid.ItemContainerStyle>
        <DataGrid.RowStyle>
            <Style TargetType="{x:Type DataGridRow}">
                <EventSetter Event="PreviewMouseDown" Handler="DataGridRowPreviewMouseDownHandler"></EventSetter>
            </Style>
        </DataGrid.RowStyle>
        <DataGrid.Columns>
            <DataGridCheckBoxColumn
                 Binding="{Binding IsSelected, RelativeSource={RelativeSource AncestorType=DataGridRow}, Mode = TwoWay}"
                 MaxWidth="25" MinWidth="25">
                <DataGridCheckBoxColumn.CellStyle>
                    <Style TargetType="DataGridCell">
                        <Setter Property="VerticalAlignment" Value="Center" />
                    </Style>
                </DataGridCheckBoxColumn.CellStyle>
            </DataGridCheckBoxColumn>
        </DataGrid.Columns>
    </DataGrid>

在我的代码背后：

    private void DataGridRowPreviewMouseDownHandler(object sender, MouseButtonEventArgs e)
    {
        if (e.LeftButton == MouseButtonState.Pressed)
        {
            var row = GetVisualParentByType((FrameworkElement)e.OriginalSource, typeof(DataGridRow)) as DataGridRow;
            if (row != null)
            {
                row.IsSelected = !row.IsSelected;
                e.Handled = true;
            }
        }
    }

    public static DependencyObject GetVisualParentByType(DependencyObject startObject, Type type)
    {
        DependencyObject parent = startObject;
        while (parent != null)
        {
            if (type.IsInstanceOfType(parent))
                break;
            else
                parent = VisualTreeHelper.GetParent(parent);
        }

        return parent;
    }

我的模型类是

public class Tags : INotifyPropertyChanged
{
    private bool _isSelected;
    public bool IsSelected
    {
        get { return _isSelected; }
        set { _isSelected = value; RaisePropertyChanged("IsSelected"); }
    }

    public int ID { get; set; }

    #region INotifyPropertyChanged
    public event PropertyChangedEventHandler PropertyChanged;

    public void RaisePropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
    #endregion
}

GridView的CataContext是一个ObservableCollection

问题在于我在DataGridRowPreviewMouseDownHandler中设置

  

row.IsSelected =！row.IsSelected;

模型未更新。

没有DataGridRowPreviewMouseDownHandler一切正常。有了它，初始绑定不起作用（例如，如果我在添加到ObservableCollection时将一个标签的IsSelected设置为true，它将显示为未选中）。知道为什么吗？

如何触发对行绑定对象的更新？