setId() 用于以编程方式生成的片段

Question

我是安卓开发新手。

我正在尝试制作一个通知菜单，所以我制作了一个片段类：

class NotificationFragment {
    private String name;

    public NotificationFragment() {}

    public NotificationFragment(String name) {
        this.name = name;
    }

    public String getName() {return this.name;}

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.notification_fragment, container, false);
    }
}

现在我想在我的屏幕上加载一个通知：

private List<int> notifications = new ArrayList<>();

private ConstraintLayer notification_layout = findViewById(R.id.aConstraintLayoutToHoldNotifications);

public load_notification(int i) {
    NotificationFragment cn = new NotificationFragment("TestName"+i);
    FragmentFrame ff = new FragmentFrame(this);
    int last_id = (notifications.size() >= 1 ? notifications.get(notifications.size() - 1) : ConstraintSet.PARENT_ID);
    int toObjectSide = (last_id == ConstraintSet.PARENT_ID? ConstraintSet.TOP : ConstraintSet.BOTTOM);

    int ff_id = View.generateViewId();
    ff.setId(ff_id);
    notification_layout.add(ff);

    ConstraintSet cs = new ConstraintSet();
    cs.clone(notification_layout);
    cs.connect(
        ff_id,
        ConstraintSet.TOP,
        last_id,
        toObjectSide
    );
    cs.applyTo(notification_layout);

    getSupportFragmentManager()
        .beginTransaction()
        .add(notificationLayerID, cn, "UIFragment")
        .commit();

    notifications.add(ff_id);
}

现在可以正常工作了。

但是，如果我再次调用它，它会引发错误java.lang.RuntimeException: All children of ConstraintLayout must have ids to use ConstraintSet，所以我尝试进行一些调试，我认为片段是需要 id 的，但片段类没有 setId()。

问题：

1) is there a way to set the id of a programmatically generated Fragment?
2) if not, is there a "hack" around this?
3) is there something that i am missing and i don't need an id on the Fragment?

注意

我尽量删减代码，帖子应该是最小可执行示例

Answer 1

这应该回答问题 1，但它可能无法解决您的问题。

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view =  inflater.inflate(R.layout.notification_fragment, container, false);
        view.setId(View.generateViewId());
        return view;
    }

或者在你的 notification_fragment.xml 中添加一个 Id 到根元素，但是如果你同时有两个通知，你很可能会遇到重复的 ids 问题。