Question

美好的一天，

我是android的新手。我想用SharedPreferences存储一些用户日期。我有一个活动 调查问卷 ，用户选择他的生日（使用名为wdullaer的datepicker自定义库），这里我有radiobutton组（知道用户是否结婚）如果用户在片段显示的关系中，建议选择伴侣生日。

当我进行活动时，它工作正常，我返回 调查问卷 活动，SharedPreferences恢复完美，并显示用户生日，radiobutton组位置，以及如果需要片段与伴侣生日。

问题是：当我关闭应用程序并重新打开时，活动中的数据将恢复，但片段（合作伙伴生日）中的数据将丢失。

抱歉我的英语不好，但我希望这个想法对你来说是可以理解的。

片段中的代码：

public class FragmentSettings extends Fragment implements DatePickerDialog.OnDateSetListener {

final static String PARTNER_YEAR = "partner_year";
final static String PARTNER_MONTH = "partner_month";
final static String PARTNER_DAY = "partner_day";
static int mYear;
static int mMonth;
static int mDay;
private TextView mDateTextView;
private SharedPreferences mSharedPreferences;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.fragment_settings, null);

    mDateTextView = (TextView) v.findViewById(R.id.partner_date_view);



    mDateTextView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Calendar now = Calendar.getInstance();
            DatePickerDialog dpd = DatePickerDialog.newInstance(
                    FragmentSettings.this,
                    now.get(Calendar.YEAR),
                    now.get(Calendar.MONTH),
                    now.get(Calendar.DAY_OF_MONTH)
            );
            dpd.setAccentColor(R.color.mdtp_accent_color);
            dpd.setThemeDark(true);
            dpd.show(getFragmentManager(), "DatePickerDialog");
        }
    });
    return v;
}

@Override
public void onDateSet(DatePickerDialog datePickerDialog, int year, int monthOfYear, int dayOfMonth) {
    mYear = year;
    mMonth = monthOfYear;
    mDay = dayOfMonth;
    String mDate = "Your partner birthday: " + dayOfMonth + "/" + (++monthOfYear) + "/" + year;
    mDateTextView.setText(mDate);

}

public void onDataSetDefault(int year, int monthOfYear, int dayOfMonth) {
    String mDate = "Your partner birthday: " + dayOfMonth + "/" + (++monthOfYear) + "/" + year;
    mDateTextView.setText(mDate);
}

public void saveUserInfo() {
    mSharedPreferences = getActivity().getPreferences(0);
    SharedPreferences.Editor editor = mSharedPreferences.edit();
    editor.putInt(PARTNER_DAY, mDay);
    editor.putInt(PARTNER_MONTH, mMonth);
    editor.putInt(PARTNER_YEAR, mYear);
    editor.commit();
    Toast.makeText(getActivity(), "Saved Fragment", Toast.LENGTH_SHORT).show();

}

public void restoreUserInfo() {
    mSharedPreferences = PreferenceManager.getDefaultSharedPreferences(getActivity().getApplicationContext());
    mYear = mSharedPreferences.getInt(PARTNER_YEAR, mYear);
    mMonth = mSharedPreferences.getInt(PARTNER_MONTH, mMonth);
    mDay = mSharedPreferences.getInt(PARTNER_DAY, mDay);

    if (mYear != 0 && mMonth != 0 && mDay != 0) {
        onDataSetDefault(mYear, mMonth, mDay);
    }

}


@Override
public void onResume() {
    super.onResume();
    restoreUserInfo();
}

@Override
public void onDestroyView() {
    super.onDestroyView();
    saveUserInfo();
}

}

问卷中的代码：

public class SettingsActivity extends AppCompatActivity implements DatePickerDialog.OnDateSetListener {

    final static String USER_YEAR = "user_year";
    final static String USER_MONTH = "user_month";
    final static String USER_DAY = "user_day";
    final static String USER_STATUS = "user_status";
    final static String USER_SEX = "user_sex";
    //Need to store in SharedPreferences
    static int mYear;
    static int mMonth;
    static int mDay;
    int mSexId;
    int mStatusId;


    private TextView mDateTextView;




    private RadioGroup mRadioSexGroup;
    private RadioButton mMaleButton;
    private RadioButton mFemaleButton;

    private RadioGroup mRadioStatusGroup;
    private RadioButton mInRelationshipButton;
    private RadioButton mSingleButton;

    private View mFragment;
    private String mDate;
    private Button mButton;
    private SharedPreferences mSharedPreferences;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_settings);


        mDateTextView = (TextView) findViewById(R.id.date_view);
        mButton = (Button) findViewById(R.id.save_button);
        mFragment = findViewById(R.id.partner_container);
        mFragment.setVisibility(View.GONE);

        mRadioSexGroup = (RadioGroup) findViewById(R.id.radioSex);
        mMaleButton = (RadioButton) findViewById(R.id.male);
        mFemaleButton = (RadioButton) findViewById(R.id.female);

        mRadioStatusGroup = (RadioGroup) findViewById(R.id.user_status);
        mInRelationshipButton = (RadioButton) findViewById(R.id.in_relationship);
        mSingleButton = (RadioButton) findViewById(R.id.status_single);






        mDateTextView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Calendar now = Calendar.getInstance();
                DatePickerDialog dpd = DatePickerDialog.newInstance(
                        SettingsActivity.this,
                        now.get(Calendar.YEAR),
                        now.get(Calendar.MONTH),
                        now.get(Calendar.DAY_OF_MONTH)
                );
                dpd.setAccentColor(R.color.mdtp_accent_color);
                dpd.setThemeDark(true);
                dpd.show(getFragmentManager(), "DatePickerDialog");

            }
        });


        mInRelationshipButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked) {
                    mFragment.setVisibility(View.VISIBLE);
                } else {
                    mFragment.setVisibility(View.INVISIBLE);
                }
            }
        });

        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                saveUserInfo();
                startActivity(new Intent(SettingsActivity.this, HomeActivity.class));
            }
        });
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_settings, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the HomeActivity/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onDateSet(DatePickerDialog datePickerDialog, int year, int monthOfYear, int dayOfMonth) {
        mYear = year;
        mMonth = monthOfYear;
        mDay = dayOfMonth;
        mDate = "Your Birthday: " + dayOfMonth + "/" + (++monthOfYear) + "/" + year;
        mDateTextView.setText(mDate);

    }

    public void onDataSetDefault(int year, int monthOfYear, int dayOfMonth) {
        mDate = "Your Birthday: " + dayOfMonth + "/" + (++monthOfYear) + "/" + year;
        mDateTextView.setText(mDate);
    }

    public void saveUserInfo() {
        mSharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
        SharedPreferences.Editor editor = mSharedPreferences.edit();
        editor.putInt(USER_DAY, mDay);
        editor.putInt(USER_MONTH, mMonth);
        editor.putInt(USER_YEAR, mYear);


        mSexId = mRadioSexGroup.getCheckedRadioButtonId();
        mStatusId = mRadioStatusGroup.getCheckedRadioButtonId();
        editor.putInt(USER_SEX, mSexId);
        editor.putInt(USER_STATUS, mStatusId);
        editor.commit();
    }

    public void restoreUserInfo() {
        mSharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
        mYear = mSharedPreferences.getInt(USER_YEAR, mYear);
        mMonth = mSharedPreferences.getInt(USER_MONTH, mMonth);
        mDay = mSharedPreferences.getInt(USER_DAY, mDay);





        if((mSharedPreferences.getInt(USER_SEX, mSexId)) == R.id.male){
           mMaleButton.setChecked(true);
        } else if ((mSharedPreferences.getInt(USER_SEX, mSexId)) == R.id.female){
            mFemaleButton.setChecked(true);
        } else {
            mMaleButton.setChecked(false);
            mFemaleButton.setChecked(false);
        }


        if(mSharedPreferences.getInt(USER_STATUS, mStatusId) == R.id.in_relationship){
            mInRelationshipButton.setChecked(true);
        }else if((mSharedPreferences.getInt(USER_STATUS, mStatusId)) == R.id.status_single){
            mSingleButton.setChecked(true);
        } else {
            mInRelationshipButton.setChecked(false);
            mSingleButton.setChecked(false);
        }


        if (mYear != 0 && mMonth != 0 && mDay != 0) {
            onDataSetDefault(mYear, mMonth, mDay);
        }

    }

    @Override
    protected void onPause() {
        super.onPause();
        saveUserInfo();
    }

    @Override
    protected void onResume() {
        super.onResume();
        restoreUserInfo();
    }
}

无论如何，谢谢你！

Answer 1

我的猜测是你保存到不同的SharedPreferences而不是从中检索。使用以下代码保存：

mSharedPreferences = getActivity().getPreferences(0);

然后你用这个恢复：

mSharedPreferences = PreferenceManager.getDefaultSharedPreferences(getActivity().getApplicationContext());

尝试在两个地方使用第二个版本。

Answer 2

使用

更改mSharedPreferences = getActivity().getPreferences(0);

mSharedPreferences=PreferenceManager.getDefaultSharedPreferences(getApplicationContext());

Answer 3

您的数据未恢复，因为您正在尝试存储数据在一个文件中，从另一个SharedPreferences文件中获取数据。

PreferenceManager.getDefaultSharedPreferences()将使用默认的首选项文件名。这将使用package name作为SharedPreferences file name，

和

getActivity().getPreferences(0);或getSharedPreferences (String name, int mode);将使用given name作为SharedPrefrence file name。

此处getActivity().getPreferences(0);只需将此活动的班级名称作为getSharedPreferences(String, int)传入，即可调用基础preferences name方法。

让它改变工作

mSharedPreferences = getActivity().getPreferences(0);

与

mSharedPreferences=PreferenceManager.getDefaultSharedPreferences(getApplicationContext());

Android：SharedPreferences在片段中不起作用

3 个答案: