如何以及在何处使用片段内的setInitialSavedState和saveFragmentInstanceState

Question

我试图创建一个Fragment在显示回来之后保留其状态的东西.

为此,我尝试使用getFragmentManager().saveFragmentInstanceState()内部onPause()然后调用setInitialSavedState()内部onCreateView().

我面临的问题是我不知道如何准确地使用它们以及何时调用它们.

这两个函数都采用类型的参数,SavedState我不知道如何使用.

码:

public class AudioContainerFragmentClass extends Fragment implements
        OnClickListener {

    final String TAG = "AudioContainerFragmentClass";
    private Button bSetName;
    private TextView tvName;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = null;
        try {
            Log.e(TAG, "onCreateView()");
            view = inflater.inflate(R.layout.audio_fragment_container, null);
            bSetName = (Button) view.findViewById(R.id.bSetName);
            tvName = (TextView) view.findViewById(R.id.tvName);
            bSetName.setOnClickListener(this);

            if(savedInstanceState != null){
                setInitialSavedState(/* WHICH SavedState OBJECT TO PASS */);
            }
            Log.e(TAG, "onCreate()");

        } catch (Exception e) {
            Log.e(TAG, "onCreateView(): " + e.toString());
        }
        return view;
    }

    /*
    @Override
    public void onSaveInstanceState(Bundle outState) {
        Log.e(TAG, "onSaveInstanceState()");
        super.onSaveInstanceState(outState);
    }
    */

    @Override
    public void onClick(View v) {
        tvName.setText("sometext");
    }

    @Override
    public void onPause() {
        super.onPause();
        getFragmentManager().saveFragmentInstanceState( /* WHAT TO ADD HERE */);

    }

}

Answer 1

只是自己调查一下,并认为我会记录我发现的东西.

setInitialSavedState()Fragment在附加到a之后无法调用Activity,如第491行的Android源代码中所述.

setInitialSavedState()旨在在代码中实例化片段后立即使用.例如:

AudioContainerFragmentClass newFrag = new AudioContainerFragmentClass();
newFrag.setInitialSavedstate(savedStateObject);