private void Helper_GotFocus(object sender, RoutedEventArgs e)
{
var helper = (DataGrid)sender;
helper.SelectedItems.Clear();
RequirementsDataGrid.Focus();
}
private void ColumnHeader_RightClickEvent(object sender, MouseButtonEventArgs e)
{
var TC = (int)(sender as System.Windows.Controls.Primitives.DataGridColumnHeader).Content;
RequirementsDataGrid.SelectedItems.Clear();
RequirementsDataGrid.Items.Cast <RequirementSingleView>()
.Where(x => x.TCIDsValue.Contains(TC))
.ToList()
.ForEach(x => RequirementsDataGrid.SelectedItems.Add(x));
RequirementsDataGrid.Focus();
}