覆盖 android.support.v4.app.fragment 中已弃用的方法

Question

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    try {
        activitycomander = (TopSectionListener) activity;
    }catch (ClassCastException e){
        throw new ClassCastException(activity.toString());
    }
}

This is the code of my java class linking with MainActivity. There is issue with onAttach method in Android Studio. It shows as strike-through with the message:

onAttach ( android.app.activity ) is deprecated:

I'm also having a second issue in MainActivity:

 public void createMeme(String top, String bottom){
    bottomsection fragmentbottom = (bottomsection) getSupportFragmentManager().findFragmentById(R.id.fragment2);
    fragmentbottom.setMemeText(top, bottom);
}

topsection and bottomsection are the names of my java classes, they are highlighted red with the message cannot resolve method .

I have done a clean rebuild on my project and checked the option to add or remove the imports automatically.

Answer 1

First question regarding onAttach is a duplicate of Android Fragment onAttach() deprecated

Regarding topsection and bottomsection , Classes should always begin with a capital letter and use CamelCaps, as per the Naming Conventions . So rename them to TopSection and BottomSection .

Also check if your class has been imported - if bottomsection is underlined then try Alt+Enter and select Import Class