Question

我创建了一个程序，可以从日期选择器手动设置不同日期的警报。代码工作正常。但如果重新启动它会丢失数据并且警报无法正常工作我怎样才能克服

我使用的代码是

    int count;
@Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    OnClickListener setClickListener = new OnClickListener() {

        @Override
        public void onClick(View v) {
            /** This intent invokes the activity DemoActivity, which in turn opens the AlertDialog window */
            Intent i = new Intent("in.com.example.demoactivity");

            /** Creating a Pending Intent */
            PendingIntent operation = PendingIntent.getActivity(getBaseContext(), count++, i, Intent.FLAG_ACTIVITY_NEW_TASK);

            /** Getting a reference to the System Service ALARM_SERVICE */
            AlarmManager alarmManager = (AlarmManager) getBaseContext().getSystemService(ALARM_SERVICE);

            /** Getting a reference to DatePicker object available in the MainActivity */
            DatePicker dpDate = (DatePicker) findViewById(R.id.dp_date);

            /** Getting a reference to TimePicker object available in the MainActivity */
            TimePicker tpTime = (TimePicker) findViewById(R.id.tp_time);

            int year = dpDate.getYear();
            int month = dpDate.getMonth();
            int day = dpDate.getDayOfMonth();
            int hour = tpTime.getCurrentHour();
            int minute = tpTime.getCurrentMinute();


            GregorianCalendar calendar = new GregorianCalendar(year,month,day, hour, minute);

            long alarm_time = calendar.getTimeInMillis();

            /** Setting an alarm, which invokes the operation at alart_time */
            alarmManager.set(AlarmManager.RTC_WAKEUP  , alarm_time , operation);

            /** Alert is set successfully */
            Toast.makeText(getBaseContext(), "Alarm is set successfully",Toast.LENGTH_SHORT).show();

        }
    };      

    OnClickListener quitClickListener = new OnClickListener() {         
        @Override
        public void onClick(View v) {
            finish();
        }
    };

    Button btnSetAlarm = ( Button ) findViewById(R.id.btn_set_alarm);
    btnSetAlarm.setOnClickListener(setClickListener);

    Button btnQuitAlarm = ( Button ) findViewById(R.id.btn_quit_alarm);
    btnQuitAlarm.setOnClickListener(quitClickListener);

}

从那里到活动片段

    public class DemoActivity extends FragmentActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {        
    super.onCreate(savedInstanceState); 

    /** Creating an Alert Dialog Window */
    AlertDemo alert = new AlertDemo();

    /** Opening the Alert Dialog Window */
    alert.show(getSupportFragmentManager(), "AlertDemo");       
}

}

从这里到创建警报框的活动

公共类AlertDemo扩展了DialogFragment {

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {

    /** Turn Screen On and Unlock the keypad when this alert dialog is displayed */
    getActivity().getWindow().addFlags(LayoutParams.FLAG_TURN_SCREEN_ON | LayoutParams.FLAG_DISMISS_KEYGUARD);


    /** Creating a alert dialog builder */
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

    /** Setting title for the alert dialog */
    builder.setTitle("Alarm");

    /** Setting the content for the alert dialog */
    builder.setMessage("An Alarm by AlarmManager");

    /** Defining an OK button event listener */
    builder.setPositiveButton("OK", new OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            /** Exit application on click OK */
            getActivity().finish();
        }                       
    });

    /** Creating the alert dialog window */
    return builder.create();
}

/** The application should be exit, if the user presses the back button */ 
@Override
public void onDestroy() {       
    super.onDestroy();
    getActivity().finish();
}

即使我重新启动设备，我也想要唤醒警报，有人请帮我解决一下

Answer 1

您必须使用BroadcastReceiver，其中必须检查Intent.ACTION_BOOT_COMPLETED并重置您在Receiver中的警报操作。例如：

public class MyBootReceiver extends BroadcastReceiver{

    @Override
    public void onReceive(Context context, Intent intent) {

        if(intent.getAction().equalsIgnoreCase(Intent.ACTION_BOOT_COMPLETED)) {
            //reset your alarm here
        }
    }

}

<强>更新

使用share-preference存储数据，或者也可以使用数据库。我使用共享偏好做了同样的事情，检查下面的代码：

public class MyBootReceiver extends BroadcastReceiver{

    @Override
    public void onReceive(Context context, Intent intent) {

        if(intent.getAction().equalsIgnoreCase(Intent.ACTION_BOOT_COMPLETED)) {
            SharedPreferences mPreferences = context.getSharedPreferences(context.getPackageName(), Context.MODE_PRIVATE);
            String datetime = mPreferences.getString("date", null);
            if(!TextUtils.isEmpty(datetime)) {
                Utility.setNotification(context);//set your alarm here.

            }
        }
    }

}

重启后不报警

1 个答案: