片段無法從Activity獲取arrayList

Question

我有一個提供ViewPager的MainActivity，在此Activity中，有一個方法在應用獲得許可后填充ArrayList。
我用一個setter傳遞了這個ArrayList，但是Fragment不考慮傳遞的值

MainActivity.java

@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    switch (requestCode) {
        case PERMISSION_REQUEST_CODE:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                Toast.makeText(context, "Permission granted", Toast.LENGTH_SHORT).show();           
                mArraySongs = listAllSongs();
                listFragment.setSongsList(mArraySongs);
                Log.d("test arraylist in activity: ", Integer.toString(mArraySongs.size()));
            } else {
                Toast.makeText(context, "Permission denied", Toast.LENGTH_SHORT).show();          
            }
            break;
    }
}

ListFragment.java

public void setSongsList(ArrayList<Song> songsList) {
    this.mSongList = songsList;
    Log.d("test fragment setSongsList", Integer.toString(mSongList.size()));
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    mInflater = inflater;
    mContext = container.getContext();
    mContainer = container;
    Log.d("test fragment onCreateView", Integer.toString(mSongList.size()));

    //check if ArrayList is empty
    if(mSongList == null || mSongList.isEmpty()){
        rootView = mInflater.inflate(R.layout.error_no_songs, mContainer, false);
    } else showListView();
    return rootView;
}

Logcat

05-06 01:36:50.118 5272-5272/com.sebb.vilify D/test fragment onCreateView: 0
05-06 01:36:50.817 5272-5272/com.sebb.vilify D/test fragment setSongsList: 7
05-06 01:36:50.817 5272-5272/com.sebb.vilify D/test arraylist in activity: 7

如何獲取通過該setter方法傳遞的值？

Answer 1

從setSongList調用showListView方法。