我有这样的代码:

private async void ContextMenuForGroupRightTapped(object sender, RightTappedRoutedEventArgs args)
{
    CheckBox ckbx = null;
    if (sender is CheckBox)
    {
        ckbx = sender as CheckBox;
    }
    if (null == ckbx)
    {
        return;
    }
    string groupName = ckbx.Content.ToString();

    var contextMenu = new PopupMenu();

    // Add a command to edit the current Group
    contextMenu.Commands.Add(new UICommand("Edit this Group", (contextMenuCmd) =>
    {
        Frame.Navigate(typeof(LocationGroupCreator), groupName);
    }));

    // Add a command to delete the current Group
    contextMenu.Commands.Add(new UICommand("Delete this Group", (contextMenuCmd) =>
    {
        SQLiteUtils slu = new SQLiteUtils();
        slu.DeleteGroupAsync(groupName); // this line raises Resharper's hackles, but appending await raises err msg. Where should the "async" be?
    }));

    // Show the context menu at the position the image was right-clicked
    await contextMenu.ShowAsync(args.GetPosition(this));
}

.．.Resharper的检查抱怨说，“因为这个调用没有被等待，所以在调用完成之前，当前方法的执行还在继续。考虑对调用结果应用'await'操作符”(在注释行上)。

因此，我在它前面加上了一个“await”，但是，当然，我还需要在某个地方添加一个“async”，但是在哪里呢?