WPF的TreeView添加鼠标双击事件MouseDoubleClick执行两次

xaml：

        <!-- TreeViewItem -->
        <Style x:Key="{x:Type TreeViewItem}" TargetType="{x:Type TreeViewItem}">
            <EventSetter Event="MouseDoubleClick" Handler="MenuItem_Click" />

cs：需要做判断，防止响应两次

        private void MenuItem_Click(object sender, RoutedEventArgs e)
        {
            TreeViewItem tviSender = sender as TreeViewItem;
            if (tviSender.IsSelected)
                MessageBox.Show("treeview被双击了");
        }