private void _keywordListView_ContextMenuOpening(object sender, ContextMenuEventArgs e)
{
var selectItems = _keywordListView.SelectedItems;
_keywordListViewDeleteMenuItem.IsEnabled = (selectItems != null && selectItems.Count > 0);
_keywordListViewCopyMenuItem.IsEnabled = (selectItems != null && selectItems.Count > 0);
_keywordListViewCutMenuItem.IsEnabled = (selectItems != null && selectItems.Count > 0);
_keywordListViewPasteMenuItem.IsEnabled = !string.IsNullOrWhiteSpace(Clipboard.GetText());
}