WPF在DataGrid单元格MouseOver上显示弹出窗口

<DataGrid x:Name="dataGrid" AutoGenerateColumns="False" ItemsSource="{Binding Items}">
    <DataGrid.Columns>
        <DataGridTextColumn Header="Column1" Binding="{Binding Column1}" />
        <DataGridTextColumn Header="Column2" Binding="{Binding Column2}" />
    </DataGrid.Columns>
    <DataGrid.CellStyle>
       <Style TargetType="DataGridCell">
           <EventSetter Event="MouseEnter" Handler="DataGridCell_MouseEnter" />
           <EventSetter Event="MouseLeave" Handler="DataGridCell_MouseLeave" />
        </Style>
    </DataGrid.CellStyle>
</DataGrid>

private void DataGridCell_MouseEnter(object sender, MouseEventArgs e)
{
    DataGridCell cell = sender as DataGridCell;
    if (cell != null)
    {
        // 显示弹出窗口
        Popup popup = new Popup();
        popup.PlacementTarget = cell;
        popup.Placement = PlacementMode.MousePoint;
        popup.IsOpen = true;
        popup.Child = new TextBlock { Text = "Hello, world!" };
    }
}

private void DataGridCell_MouseLeave(object sender, MouseEventArgs e)
{
    DataGridCell cell = sender as DataGridCell;
    if (cell != null)
    {
        // 隐藏弹出窗口
        Popup popup = cell.FindResource("popup") as Popup;
        if (popup != null)
        {
            popup.IsOpen = false;
        }
    }
}