android - 如何等到 fragment 被删除

Question

我有一个包含动态 fragment 的 Activity 。我需要运行一些代码 after 一个 fragment 被删除但是 remove(myFragment).commit() 是异步执行的，我不知道 fragment 何时被删除。这是我的代码:

final FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.remove(myFragment).commit();
//wait until the fragment is removed and then execute rest of my code

来自文档:

public abstract int commit ()

Schedules a commit of this transaction. The commit does not happenimmediately; it will be scheduled as work on the main thread to bedone the next time that thread is ready.

Answer 1

如果您使用 fragment 的 onDetach 方法调用 Activity 并告诉它已完成，会怎样？

class MyFrag extends Fragment {

    private Activity act;

    @Override
    public void onAttach(Activity activity) {
        act = activity;
    }

    @Override
    public void onDetatch() {
        act.fragGone();
    }
}

在 Activity 中:

public void fragGone() {
    //do something, update a boolean, refresh view, etc.
}