在特定时间重置整数值

Question

我目前有一个片段,有几个按钮,并包含一个onClickListener.每次单击其中一个按钮时,计数器变量将增加1,并使用SharedPreferences设置为另一个片段中TextView的文本.

即使应用程序完全关闭,计数器也会保持不变,并且会在应用程序的后续运行中显示.

我的新目标是在每天结束时将计数器重置为0(准确地说是23:59:00).

我决定避免使用Google搜索来解决这个问题,并在Android Developer docs上找到了TimerTask,Calendar,Timer和Date API; 我试图让这个与这些API一起使用.不幸的是,它没有像我计划的那样运作.变量被重新设置为0,但他们留在零,只会增加多达1,并返回到0每次我退出该应用程序的时间.

有没有更好的方法来解决这个问题？或者我的方法是否足够,我只需要调整/更改一些代码？

其中一个问题可能是我正在更改计数器变量引用(如果是,我应该在哪里更改它)？

这是我尝试的:

FirstFragment

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflating the layout
        View v = inflater.inflate(R.layout.starting_fragment, container, false);

        //Instantiate new Timer
        Timer timer = new Timer();
        // Creates a Calendar object that specifies a specific time of day
        Calendar cal = Calendar.getInstance();
        cal.setTimeInMillis(System.currentTimeMillis());
        cal.set(Calendar.HOUR_OF_DAY, 20);
        cal.set(Calendar.MINUTE, 57);
        cal.set(Calendar.SECOND, 00);
        cal.set(Calendar.MILLISECOND, 00);

        // Instantiate a day object and use the time of day from cal object as its data
        Date date = cal.getTime();

        TimerTask tt = new TimerTask() {
            // Sets the counter variables back to 0
            @Override
            public void run() {
                COUNT_OOL = 0;
                COUNT_WTE = 0;
                COUNT_BLO = 0;
                COUNT_BLK = 0;
                COUNT_HBL = 0;
                COUNT_GRN = 0;
                COUNT_MTE = 0;

            }
        };
        // Resets the counter variables (to 0) at the time specified by the date object
        timer.schedule(tt, date);

        // Stores count for each button back into their respective count variable
        // Initializes the value from previous runs of app to subsequent runs of app
        // This way, count variables will never get set back to 0 after onDestroy()
        COUNT_OOL = getActivity().getSharedPreferences("keyname", Context.MODE_PRIVATE).getInt("oolongCount", 0);
        COUNT_WTE = getActivity().getSharedPreferences("keyname", Context.MODE_PRIVATE).getInt("whiteCount", 0);
        COUNT_BLO = getActivity().getSharedPreferences("keyname", Context.MODE_PRIVATE).getInt("bloomingCount", 0);
        COUNT_BLK = getActivity().getSharedPreferences("keyname", Context.MODE_PRIVATE).getInt("blackCount", 0);
        COUNT_HBL = getActivity().getSharedPreferences("keyname", Context.MODE_PRIVATE).getInt("herbalCount", 0);
        COUNT_GRN = getActivity().getSharedPreferences("keyname", Context.MODE_PRIVATE).getInt("greenCount", 0);
        COUNT_MTE = getActivity().getSharedPreferences("keyname", Context.MODE_PRIVATE).getInt("mateCount", 0);

增加计数器变量的onClick方法:

 @Override
    public void onClick(View view) {
        int id = view.getId();
        /*
         * Use the View interface with OnClickListener to get the Button ID's
         * Then you can run a switch on the Buttons (because normally switches
         * cannot be run on buttons
         */

        if (id == R.id.tea_type1) {
            Builder oolongBuilder = new AlertDialog.Builder(StartingFragment.this.getActivity(),
                    AlertDialog.THEME_HOLO_LIGHT);

            oolongBuilder.setPositiveButton("Hot",
                    //Starts OolongTeaActivity for hot tea when clicked
                    new DialogInterface.OnClickListener() {

                        @Override
                        public void onClick(DialogInterface arg0, int arg1) {
                            Intent i = new Intent(StartingFragment.this.getActivity(),
                                    OolongTeaActivity.class);
                            StartingFragment.this.getActivity().startActivity(i);
                        }
                    });

            oolongBuilder.setNeutralButton("Iced",

                    new DialogInterface.OnClickListener() {

                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Intent i = new Intent(StartingFragment.this.getActivity(),
                                    ColdOolongTeaActivity.class);
                            StartingFragment.this.getActivity().startActivity(i);

                        }
                    });

            oolongBuilder.setTitle("Oolong Tea");
            oolongBuilder.setMessage("How Do You Like Your Tea?");

            AlertDialog oolongDialog = oolongBuilder.create();
            oolongDialog.show();

            COUNT_OOL++;
            SharedPreferences pref1 = getActivity().getSharedPreferences("keyname", Context.MODE_PRIVATE);
            SharedPreferences.Editor editor1 = pref1.edit();
            editor1.putInt("oolongCount", COUNT_OOL);
            editor1.commit();

        }

SecondFragment(将计数器设置为TextViews的文本):

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

        View rootView = inflater.inflate(R.layout.fragment_tea_counter, container, false);

        oolongCounterText = (TextView) rootView.findViewById(R.id.oolong_counter_tv);

        SharedPreferences pref1 = getActivity().getSharedPreferences("keyname", Context.MODE_PRIVATE);
        Integer counter1 = pref1.getInt("oolongCount", 0);
        String s1 = String.valueOf(counter1);
        oolongCounterText.setText(s1);

Answer 1

我个人会考虑使用AlarmManager和日历来设置时间。然后，您将启动一个服务来完成您需要做的一切。

Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.HOUR_OF_DAY, 23);
calendar.set(Calendar.MINUTE, 59);
calendar.set(Calendar.SECOND, 59);
calendar.set(Calendar.MILLISECOND, 0);
PendingIntent pi = PendingIntent.getService(context, 0,
            new Intent(context, MyService.class),PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
am.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
                                AlarmManager.INTERVAL_DAY, pi);

将 MyService 替换为实际的Service，当服务启动时，它可以： 1）将数字重置回 0 2）检查应用程序是否正在运行，以查看是否需要立即更新文本框或者是否可以等待用户启动应用程序 3) 停止服务

在遵循此代码之前需要调查的事项：

确保AlarmManager适合您，重复警报在重新启动后不会运行（感谢Jawnnypoo澄清了这一点）请参阅下面的评论，其中他链接到 BroadcastReceiver，以便AlarmManager在重新启动后运行。