Android Studio 多个 SharedPreferences 保存在 1 个键值下？

Question

我有 5 个不同的字符串值需要保存在各自的 SharedPreferences 键下。但是，它们只保存为我为 editClass5Text 设置的内容。

我已经尝试将我的关键字符串设置为最终字符串和/或将它们初始化为字符串，但结果却是

private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";

// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;

private SharedPreferences sp;
private SharedPreferences.Editor editor;
private static final String SAVEFILE = "saveFile";

private EditText editClass1Text, editClass2Text, editClass3Text, editClass4Text, editClass5Text;
private String class1TextSAVEFILE;
private String class2TextSAVEFILE;
private String class3TextSAVEFILE;
private String class4TextSAVEFILE;
private String class5TextSAVEFILE;
private Button button;
private View view;

public ClassSettings() {
    // Required empty public constructor
}

/**
 * Use this factory method to create a new instance of
 * this fragment using the provided parameters.
 *
 * @param param1 Parameter 1.
 * @param param2 Parameter 2.
 * @return A new instance of fragment Class1.
 */
// TODO: Rename and change types and number of parameters
public static ClassSettings newInstance(String param1, String param2) {
    ClassSettings fragment = new ClassSettings();
    Bundle args = new Bundle();
    args.putString(ARG_PARAM1, param1);
    args.putString(ARG_PARAM2, param2);
    fragment.setArguments(args);
    return fragment;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    if (getArguments() != null) {
        mParam1 = getArguments().getString(ARG_PARAM1);
        mParam2 = getArguments().getString(ARG_PARAM2);
    }
    //initialize the SharedPreferences and the editor in onCreate so it is the first thing the fragment does.
    sp = this.getActivity().getSharedPreferences("classSettings", Context.MODE_PRIVATE);
    editor = sp.edit();

}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    //we initialize the view and set it to the inflater,
    //so that we can return button, edit text, and set text in the inflater also.
    view = inflater.inflate(R.layout.fragment_class_settings, container, false);

    button = (Button) view.findViewById(R.id.buttonn);
    button.setOnClickListener(this);

    editClass1Text = (EditText) view.findViewById(R.id.class1);
    editClass1Text.setText(sp.getString(null, class1TextSAVEFILE), TextView.BufferType.EDITABLE);

    editClass2Text = (EditText) view.findViewById(R.id.class2);
    editClass2Text.setText(sp.getString(null, class2TextSAVEFILE), TextView.BufferType.EDITABLE);

    editClass3Text = (EditText) view.findViewById(R.id.class3);
    editClass3Text.setText(sp.getString(null, class3TextSAVEFILE), TextView.BufferType.EDITABLE);

    editClass4Text = (EditText) view.findViewById(R.id.class4);
    editClass4Text.setText(sp.getString(null, class4TextSAVEFILE), TextView.BufferType.EDITABLE);

    editClass5Text = (EditText) view.findViewById(R.id.class5);
    editClass5Text.setText(sp.getString(null, class5TextSAVEFILE), TextView.BufferType.EDITABLE);

    // return the view statement that includes the inflater, button edittext, and edittext.settext.
    return view;
}

public void onClick(View v){
    //change the EditText object to a String and save it to the sp class1

    editor.putString(class1TextSAVEFILE, editClass1Text.getText().toString());
    editor.putString(class2TextSAVEFILE, editClass2Text.getText().toString());
    editor.putString(class3TextSAVEFILE, editClass3Text.getText().toString());
    editor.putString(class4TextSAVEFILE, editClass4Text.getText().toString());
    editor.putString(class5TextSAVEFILE, editClass5Text.getText().toString());
    editor.commit();

    //sets the text saved to the EditText object, and saves it as editable.
    editClass1Text.setText(sp.getString(null, class1TextSAVEFILE), TextView.BufferType.EDITABLE);
    editClass2Text.setText(sp.getString(null, class2TextSAVEFILE), TextView.BufferType.EDITABLE);
    editClass3Text.setText(sp.getString(null, class3TextSAVEFILE), TextView.BufferType.EDITABLE);
    editClass4Text.setText(sp.getString(null, class4TextSAVEFILE), TextView.BufferType.EDITABLE);
    editClass5Text.setText(sp.getString(null, class5TextSAVEFILE), TextView.BufferType.EDITABLE);
}


@Override
public void onAttach(Context context) {
    super.onAttach(context);
    if (context instanceof OnFragmentInteractionListener) {
        mListener = (OnFragmentInteractionListener) context;
    } else {
        throw new RuntimeException(context.toString()
                + " must implement OnFragmentInteractionListener");
    }
}

@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}

/**
 * This interface must be implemented by activities that contain this
 * fragment to allow an interaction in this fragment to be communicated
 * to the activity and potentially other fragments contained in that
 * activity.
 * <p>
 * See the Android Training lesson <a href=
 * "http://developer.android.com/training/basics/fragments/communicating.html"
 * >Communicating with Other Fragments</a> for more information.
 */
public interface OnFragmentInteractionListener {
    // TODO: Update argument type and name
    void onFragmentInteraction(Uri uri);
}

Answer 1

您没有为变量分配任何字符串，默认情况下 String 被分配为 null。这就是您能够保存 editClass5Text 值的原因。

null key , editClass4Text value (replaced by editClass3Text)

null key, editClass5Text value replaced by editClass4Text)

按以下方式分配变量

private String class1TextSAVEFILE = "k1";

private String class2TextSAVEFILE = "k2";

private String class3TextSAVEFILE = "k3";

private String class4TextSAVEFILE = "k4";

private String class5TextSAVEFILE = "k5";