使用alarmManager和service从服务器重复获取数据

Question

我的问题是我想每两个小时验证一下数据库中是否有新数据，为此我创建了这个用户界面:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
        <EditText
            android:id="@+id/speedAlert"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:ems="10"
            android:gravity="center"
            android:hint="km/h"
            android:inputType="number" />
        <CheckBox
            android:id="@+id/checkBoxSpeed"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />
<Button
    android:id="@+id/btnConfirmSpeed"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Confirm" />

因此，当用户输入edittext的值并勾选复选框并点击按钮确认时，将创建一个警报，并且每两小时该警报启动一次服务:

btnConfirmSpeed.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            cal = Calendar.getInstance();
            triggerAtTime = cal.getTimeInMillis()+ (1 * 30 * 60 * 1000); // starts in 30 minutes
            repeat_alarm_every = (2 * 60 * 60 * 1000); // repeat every 2 hour
            int _id = (int) System.currentTimeMillis();
            Intent intent = new Intent(Alarm.this, NotificaSpeed.class);
            //get the value of checkbox from sharedpreferences
                    boolean tgpref = pref.getBoolean("checkVitessePref", false); 
            String sp = speedAlert.getText().toString();
            if(checkBoxSpeed.isChecked()){
                if(sp.matches(""))
                    Toast.makeText(getApplicationContext(), "specify speed", Toast.LENGTH_SHORT).show();
                else 
                {
                    editor = pref.edit();
                    editor.putBoolean("checkVitessePref", true); // value to store
                    editor.putInt("speedalarm", Integer.parseInt(speedAlert.getText().toString()));
                    editor.commit();
                    pintent = PendingIntent.getService(Alarm.this, _id, intent, 0);
                    alarm = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
                    alarm.setRepeating(AlarmManager.RTC_WAKEUP, triggerAtTime, repeat_alarm_every, pintent);

                } 
            }else {
                alarm.cancel(pintent);
                editor.putBoolean("checkVitessePref", false); // value to store
                editor.commit();
                stopService(new Intent(Alarm.this,NotificaSpeed.class));
            }
        }
    });

notificspeed是服务:

public class NotificaSpeed extends Service{
@Override
public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    return null;
}
@Override
public void onCreate() {
    mNotificationManager = (NotificationManager) getSystemService(ns);
    super.onCreate();
}
@Override
public void onDestroy() {
    super.onDestroy();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    new VerifySpeedCar().execute();
    return super.onStartCommand(intent, flags, startId);
}
public void notification(int carsNumber, int speed){
    NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(NotificaSpeed.this);
    if(carsNumber != 0)
        notificationBuilder.setContentTitle(carsNumber+" cars are exceeding the speed");
                        .setSmallIcon(R.drawable.ic_launcher)
                        .setAutoCancel(true);
    final int _idI = (int) System.currentTimeMillis();
    Intent notificationIntent = new Intent(NotificaSpeed.this, ListCars.class);
    PendingIntent contentIntent = PendingIntent.getActivity(this, _idI, notificationIntent, 0);
    notificationBuilder.setContentIntent(contentIntent);
    notificationBuilder.setDefaults(Notification.DEFAULT_SOUND | Notification.DEFAULT_LIGHTS | Notification.DEFAULT_VIBRATE);
    mNotificationManager.notify(SIMPLE_NOTIFICATION_ID, notificationBuilder.build());
}
class VerifySpeedCar extends AsyncTask<String, String, String> {
protected String doInBackground(String... args) {
    // Building Parameters
    List<NameValuePair> params = new ArrayList<NameValuePair>();
    params.add(new BasicNameValuePair(TAG_ACCOUNTID, accountID));
    params.add(new BasicNameValuePair(TAG_SPEEDKPH, ""+speedpref)); // how can I get the value of edittext of the speed from the sharedpreferences?
        JSONObject json = jParser.makeHttpRequest(url, "GET", params);
        try {
            int success = json.getInt(TAG_SUCCESS);
            if (success == 1) {
                cars = json.getJSONArray(TAG_CARS);
                carsNumber = cars.length();
            } else 
                carsNumber = 0;
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
    return null;
}
protected void onPostExecute(String file_url) {
  if( carsNumber != 0){
      notification(carsNumber, speedpref);
  }
}}}

首先，这是进行验证的好方法还是我做错了?其次，我如何从sharedpreferences中获得edittext的值?最后，当我关闭应用程序时，服务也停止了，所以当我再次启动应用程序时，服务不再运行，但复选框的值仍然被选中，我该如何解决这个问题?

感谢您花时间阅读我的问题。如有任何帮助，不胜感激

Answer 1

如何从SharedPreference获得edittext的值?

创建SharedPreference和SharedPreference。编辑对象。

 SharedPreferences sp ;
 sp = this.getSharedPreferences("YOUR PREF NAME", 0);

我相信你得到的值从edittext字符串str如

str = ed.getText().toString();
SharedPreferences.Editor editor = sp.edit();
editor.putString("edit_text", str);
editor.commit();

从SharedPreference中检索edittext值

如果你在同一活动中检索，则

String value = sp.getString("edit_text", null);

如果在不同的活动中，那么首先像这样实例化SharedPreference

SharedPreference sp = this.getSharedPreferences("YOUR PREF NAME", 0);