android - 从片段中调用父母的活动

Question

如果我在 Fragment 中，我该如何调用父母的活动？

Answer 1

是的，通过调用 getActivity 并将其与父活动一起转换以访问其方法或变量是正确的((ParentActivityName)getActivity())

试试这个。

ParentActivityName是父类名

Answer 2

2021 更新

正如评论中所说，Fragment#onAttach(Activity) 从 API 23 开始不推荐使用。反而：

@Override
public void onAttach(Context ctx) {
    super.onAttach(ctx);
    
    // This makes sure that the container activity has implemented
    // the callback interface. If not, it throws an exception
    try {
        // Only attach if the caller context is actually an Activity
        if (ctx instanceof Activity) {
          mCallback = (OnHeadlineSelectedListener) ctx;
        }
    } catch (ClassCastException e) {
          throw new ClassCastException(ctx.toString()
                + " must implement OnHeadlineSelectedListener");
    }
}

---

原始答案

最合适的方法是让您Activity实现Interface和使用 listeners。这样，它就Fragment不会与任何特定的Activity保持它的可重复使用联系在一起。进入Fragment：

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    
    // This makes sure that the container activity has implemented
    // the callback interface. If not, it throws an exception
    try {
        mCallback = (OnHeadlineSelectedListener) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString()
                + " must implement OnHeadlineSelectedListener");
    }
}

这样，Activity当片段附加到片段时，您就会听到片段。

也可以看看：

• http://developer.android.com/training/basics/fragments/communicating.html

Answer 3

只需使用 getActivity() 方法调用您的父活动。

CardView cardView = (CardView) getActivity().findView(R.id.your_view);