SharedPreferences和TimePickerDialog

Question

万岁！

我正在尝试编写我的第一个Android应用程序，但我遇到了障碍。

我想让用户设置一个‘开始’和‘停止’的时间，为每日计划。我已经成功地实现了TimePickerDialog，以及它旁边的TextView，但我永远也想不出如何将用户选择的时间保存为SharedPreferences字符串。

代码如下(为清晰起见，请将其删减)：

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.setup);
        // Retrieve the shared preferences
        mUserSettings = getSharedPreferences(USER_PREFERENCES, MODE_PRIVATE);

        // capture our View elements
        mTimeDisplayStart = (TextView)  findViewById(R.id.TextView_ScheduleStart_Info);
        mPickTimeStart = (Button) findViewById(R.id.Button_ScheduleStart);

        // add a click listener to the button
        mPickTimeStart.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                showDialog(TIME_DIALOG_START);
            }
        });

        // get the current time
        final Calendar c = Calendar.getInstance();
        mHourStart = c.get(Calendar.HOUR_OF_DAY);
        mMinuteStart = c.get(Calendar.MINUTE);

        // display the current date
        updateDisplayStart();
    }

    // updates the time we display in the TextView
    private void updateDisplayStart() {
        mTimeDisplayStart.setText(
                new StringBuilder()
                .append(padStart(mHourStart)).append(":")
                .append(padStart(mMinuteStart)));
    }

    private static String padStart(int c) {
        if (c >= 10)
            return String.valueOf(c);
        else
            return "0" + String.valueOf(c);
    }

    // the callback received when the user "sets" the time in the dialog
    private TimePickerDialog.OnTimeSetListener mTimeSetListenerStart =
        new TimePickerDialog.OnTimeSetListener() {
            public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
                mHourStart = hourOfDay;
                mMinuteStart = minute;
                updateDisplayStart();
            }
        };

    @Override
    protected Dialog onCreateDialog(int id) {
        switch (id) {
        case TIME_DIALOG_START:
            return new TimePickerDialog(this,
                    mTimeSetListenerStart, mHourStart, mMinuteStart, false);
        }
        return null;
    }

我假设应该在更新TextView的同时节省时间……但我不知道该怎么做。

我现在已经花了5到6个小时寻找答案，但我真的找不到一个。我已经用SharedPreferences.Editor进行了试验，但这不起作用，因为我需要将时间存储为一个长时间，而不是一个字符串。

我已经无能为力了，我真的很感谢你的帮助！

Answer 1

你必须这样做

private TimePickerDialog.OnTimeSetListener mTimeSetListenerStart =
        new TimePickerDialog.OnTimeSetListener() {
            public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
                mHourStart = hourOfDay;
                mMinuteStart = minute;
                updateDisplayStart();

                Calendar cal = Calendar.getInstance();
                cal.set(Calendar.HOUR_OF_DAY, hourOfDay);
                cal.set(Calendar.MINUTE, minute);
                mUserSettings.edit().putLong("starttime", cal.getTimeInMillis()).commit();

            }
        };

Answer 2

在以下方法中

    // updates the time we display in the TextView
         private void updateDisplayStart() {
            mTimeDisplayStart.setText(
                    new StringBuilder()
                    .append(padStart(mHourStart)).append(":")
                    .append(padStart(mMinuteStart)));
        });

     SharedPreferences settingsActivity = getSharedPreferences("todolist1",
                    Activity.MODE_PRIVATE);
            SharedPreferences.Editor prefEditor = settingsActivity.edit();

            prefEditor.putString("DateToDisplay",new StringBuilder()
                    .append(padStart(mHourStart)).append(":")
                    .append(padStart(mMinuteStart));  // updates the time we display in the TextView



        prefEditor.commit();
}

在此之后，您希望从共享首选项中检索数据的位置如下

SharedPreferences settingsActivity = getSharedPreferences("todolist1",
                Activity.MODE_PRIVATE);

        if (settingsActivity.contains(DateToDisplay)) {
            String saveddate = settingsActivity
                    .getString(DateToDisplay, "");

Answer 3

SharedPreferences支持long%s。您可以这样做

SharedPreferences prefs = getSharedPreferences("prefs", Context.MODE_PRIVATE); prefs.edit().putLong("longKey", longValue).commit();

来存储值。要检索它，您可以这样做

SharedPreferences prefs = getSharedPreferences("prefs", Context.MODE_PRIVATE); long longValue = prefs.getLong("longKey", 0l);