Android 如何停止timer.scheduleAtFixedRate？

我正在开发一个简单的报警应用程序。 我创建了一个具有scheduledAtFixedRate的服务，以检查当前小时是否与设置的小时匹配。如果我多次设置时间，当其中一个时间设置出现时，每隔一个时间设置就会关闭，例如：当前时间为20:00，我将闹钟设置为9:10、9:20和20:01，当时间为20:01时，3个唤醒活动同时出现。我想不出原因。代码如下： 主要活动：

    package com.example.lalarm;

import android.content.Intent;
import android.content.SharedPreferences;
import android.net.Uri;
import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.Toast;

public class MainActivity extends PreferenceActivity {
    TimePicker timePicker;

    protected static int hourSet;
    protected static int minuteSet;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.alarm_preferences);
        setContentView(R.layout.activity_main);
        getActionBar().setDisplayShowTitleEnabled(false);

        timePicker = (TimePicker)findViewById(R.id.timePicker1);
        timePicker.setIs24HourView(true);       

        }

    @Override
    public boolean onCreateOptionsMenu (Menu menu){
        super.onCreateOptionsMenu(menu);
        CreateMenu(menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item){
        return MenuChoice(item);
    }

    private void CreateMenu (Menu menu){
        MenuItem mi1 = menu.add(0, 1, 1, "Stop");
        {mi1.setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);}
        MenuItem mi2 = menu.add(0, 2, 2, "Save");
        {mi2.setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);}
    }

    private boolean MenuChoice (MenuItem item){
        switch (item.getItemId()){
        case 2:
            Intent i = new Intent("com.example.AlarmService1");
            stopService(i);     
            hourSet = timePicker.getCurrentHour();
            minuteSet = timePicker.getCurrentMinute();
            i.putExtra("hourSet", hourSet);
            i.putExtra("minuteSet", minuteSet);
            startService(i);
            Toast.makeText(getBaseContext(), "Alarm set", Toast.LENGTH_LONG).show();
            return true;
        case 1:
            stopService(new Intent("com.example.AlarmService1"));
            return true;
        }
        return false;
    }

}

服务：

 package com.example.lalarm;

import android.app.Notification;

import java.util.Timer;
import java.util.TimerTask;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.support.v4.app.NotificationCompat;
import android.text.format.Time;
import android.util.Log;

public class AlarmService extends Service {

    int counter = 0;
    private static int hourSet, minuteSet;
    private static int currentHour, currentMinute;
    static final int UPDATE_INTERVAL = 6_000;
    private Timer timer = new Timer();
    Time time = new Time();

    @Override
    public IBinder onBind(Intent arg0){
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startID){

        NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
        builder.setSmallIcon(R.drawable.alarm_512).setContentTitle("Alarm").setContentText("Alarm is on");                          
        Notification notification = builder.build();
        startForeground(1, notification);
        hourSet = intent.getIntExtra("hourSet", 0);
        minuteSet = intent.getIntExtra("minuteSet", 0);
        Log.d("Service", "before checkTime()");
        checkTime();
        Log.d("Service", "after checkTime()");
        return START_STICKY;
    }

    private void checkTime(){
        timer.scheduleAtFixedRate(new TimerTask() {     
            public void run() {
                time.setToNow();
                currentHour = time.hour;
                currentMinute = time.minute;
                if(currentHour == hourSet && currentMinute == minuteSet){                   
                    Log.d("Service", "inside if statement");
                    Intent i = new Intent("com.example.AlarmTime1");
                    i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                    startActivity(i);
                    cancel();
                }               
            }
        }, 0, UPDATE_INTERVAL   );
    }

    @Override
    public void onDestroy(){
        super.onDestroy();
        stopForeground(true);
        }


}

日志：

12-01 21:44:51.501: D/Service(567): ****before checkTime()****
12-01 21:44:51.511: D/Service(567): ****after checkTime()****
12-01 21:44:51.601: I/WindowManager(94): createSurface Window{415c1f20 Toast paused=false}: DRAW NOW PENDING
12-01 21:44:51.662: D/dalvikvm(567): GC_CONCURRENT freed 186K, 3% free 11269K/11591K, paused 4ms+17ms
12-01 21:44:51.871: D/dalvikvm(147): GC_FOR_ALLOC freed 4974K, 32% free 11089K/16199K, paused 262ms
12-01 21:44:51.871: I/dalvikvm-heap(147): Grow heap (frag case) to 11.909MB for 1048592-byte allocation
12-01 21:44:52.341: D/dalvikvm(147): GC_CONCURRENT freed 32K, 26% free 12081K/16199K, paused 5ms+7ms
12-01 21:44:53.390: D/Service(567): ****before checkTime()****
12-01 21:44:53.390: D/Service(567): ****after checkTime()****
12-01 21:44:54.041: D/dalvikvm(147): GC_CONCURRENT freed 408K, 24% free 12330K/16199K, paused 5ms+7ms
12-01 21:44:55.051: I/WindowManager(94): createSurface Window{4169bff8 Toast paused=false}: DRAW NOW PENDING
12-01 21:45:02.281: D/Service(567): ****before checkTime()****
12-01 21:45:02.281: D/Service(567): ****inside if statement****
12-01 21:45:02.281: I/ActivityManager(94): START {act=com.example.AlarmTime1 flg=0x10000000 cmp=com.example.lalarm/.AlarmTime} from pid 567
12-01 21:45:02.291: W/WindowManager(94): Failure taking screenshot for (180x273) to layer 21010
12-01 21:45:02.301: D/Service(567): ****after checkTime()****
12-01 21:45:02.461: I/WindowManager(94): createSurface Window{415e1108 Toast paused=false}: DRAW NOW PENDING
12-01 21:45:03.011: D/dalvikvm(147): GC_CONCURRENT freed 749K, 24% free 12314K/16199K, paused 5ms+8ms
12-01 21:45:03.091: D/AudioSink(38): bufferCount (4) is too small and increased to 12
12-01 21:45:03.440: I/WindowManager(94): createSurface Window{4163a730 com.example.lalarm/com.example.lalarm.AlarmTime paused=false}: DRAW NOW PENDING
12-01 21:45:03.501: D/Service(567): ****inside if statement****
12-01 21:45:03.501: I/ActivityManager(94): START {act=com.example.AlarmTime1 flg=0x10000000 cmp=com.example.lalarm/.AlarmTime} from pid 567
12-01 21:45:03.511: W/WindowManager(94): Failure taking screenshot for (180x273) to layer 21015
12-01 21:45:04.201: D/AudioSink(38): bufferCount (4) is too small and increased to 12
12-01 21:45:04.291: I/WindowManager(94): createSurface Window{414b6ee0 com.example.lalarm/com.example.lalarm.AlarmTime paused=false}: DRAW NOW PENDING
12-01 21:45:04.621: I/ActivityManager(94): Displayed com.example.lalarm/.AlarmTime: +2s225ms
12-01 21:45:04.711: I/ARMAssembler(36): generated scanline__00000077:03010104_00008001_00000000 [ 89 ipp] (110 ins) at [0x41dbd450:0x41dbd608] in 7341190 ns
12-01 21:45:04.881: I/ActivityManager(94): Displayed com.example.lalarm/.AlarmTime: +1s96ms
12-01 21:45:05.351: D/dalvikvm(567): GC_CONCURRENT freed 276K, 4% free 11452K/11847K, paused 4ms+7ms
12-01 21:45:05.392: D/Service(567): ****inside if statement****
12-01 21:45:05.401: I/ActivityManager(94): START {act=com.example.AlarmTime1 flg=0x10000000 cmp=com.example.lalarm/.AlarmTime} from pid 567
12-01 21:45:05.411: W/WindowManager(94): Failure taking screenshot for (180x273) to layer 21020
12-01 21:45:05.801: D/AudioSink(38): bufferCount (4) is too small and increased to 12
12-01 21:45:05.900: I/WindowManager(94): createSurface Window{41649658 com.example.lalarm/com.example.lalarm.AlarmTime paused=false}: DRAW NOW PENDING
12-01 21:45:07.061: I/ActivityManager(94): Displayed com.example.lalarm/.AlarmTime: +1s556ms
12-01 21:45:07.561: W/WindowManager(94): Failure taking screenshot for (180x273) to layer 21025
12-01 21:45:07.661: I/WindowManager(94): createSurface Window{414b6ee0 com.example.lalarm/com.example.lalarm.AlarmTime paused=false}: DRAW NOW PENDING
12-01 21:45:08.400: W/WindowManager(94): Failure taking screenshot for (180x273) to layer 21020
12-01 21:45:08.481: I/WindowManager(94): createSurface Window{4163a730 com.example.lalarm/com.example.lalarm.AlarmTime paused=false}: DRAW NOW PENDING
12-01 21:45:09.070: W/WindowManager(94): Failure taking screenshot for (180x273) to layer 21015
12-01 21:45:09.141: I/WindowManager(94): createSurface Window{41677078 com.example.lalarm/com.example.lalarm.MainActivity paused=false}: DRAW NOW PENDING
12-01 21:46:04.771: W/ThrottleService(94): unable to find stats for iface rmnet0
: E/(): Device disconnected

---

由于if语句中的日志重复出现，我猜scheduleAtFixedRate有问题。我试图在活动启动后取消，但它不起作用。那么如何解决这个问题呢？

用定时器试过了。取消？我试过了，但是不行