C# XAML GettingFocus参数异常

我们正在尝试使用GettingFocus将焦点从祖先控件重定向到子控件，但在某些情况下会抛出异常

到目前为止，我注意到的情况如下：

NewFocusedElement的实际高度或实际宽度为0

NewFocusedElement无法获取焦点

是否仍要保护args.NewFocusedElement=element

我们正在捕获异常作为临时解决方案

代码如下：

private void OnGettingFocus(UIElement sender, GettingFocusEventArgs args)
        {
            if ((args.Direction == FocusNavigationDirection.Up || args.Direction == FocusNavigationDirection.Down)
                && (sender == this) && (DefaultFocusButton != null))
                // Add extra guard here so that the try / catch is no longer needed
            {
                try
                {
                    args.NewFocusedElement = DefaultFocusButton;
                }
                catch (ArgumentException e)
                {
                    // This focus redirect causes an exception when the element can't receive focus
                }
            }
        }