Question

我正在实现在后台运行服务，服务将停止并开始点击切换按钮。服务在第一个活动中启动，并在单击切换按钮时在另一个活动中停止服务。当我运行应用程序服务时我在第一个活动中自动启动，我在第一个活动中的onCreate（）方法启动，另一个活动切换按钮状态已经开启，但是当我切换按钮将关闭服务停止但是当我回到第一个活动服务时再次启动。请任何人都可以帮助我。这是我的代码

public class MyService extends Service
{
    private static final String TAG = "MyService";
    MediaPlayer player;
    private final String StrMyService="myservice";



    @Override
    public IBinder onBind(Intent arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public void onCreate() {
        Toast.makeText(this, "My Service Created", Toast.LENGTH_LONG).show();
        Log.d(TAG, "onCreate");

        player = MediaPlayer.create(this, R.raw.braincandy);
        player.setLooping(false); // Set looping
    }

    @Override
    public void onDestroy() {
        Toast.makeText(this, "My Service Stopped", Toast.LENGTH_LONG).show();
        Log.d(TAG, "onDestroy");
        player.stop();
    }

    @Override
    public void onStart(Intent intent, int startid) {
        Toast.makeText(this, "My Service Started", Toast.LENGTH_LONG).show();
        Log.d(TAG, "onStart");
        player.start();
    }
}




public class Service_Demo extends Activity implements OnClickListener 
{
      private static final String TAG = "ServicesDemo";


      @Override
      public void onCreate(Bundle savedInstanceState)
      {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        System.out.println("In OnCreate(");
        startService(new Intent(this, MyService.class));


      }
}


public class Toggle_Activity extends Activity
{
    ToggleButton tgButton;
    private boolean isService=false;
    private String strService;
    public final String service_Prefs="servicePrefs";
    private static final String StrMyService = "zdf";


    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.toggle);

        final SharedPreferences servicePrefs=this.getSharedPreferences("Service_Prefs",MODE_WORLD_READABLE);
        strService=servicePrefs.getString(StrMyService , "myservice");
        Log.e("",""+strService);

        final boolean mBool = servicePrefs.getBoolean("myservice", true);
        Log.e("Boolean Value mBool","="+mBool);
        Boolean b = mBool;
        Log.e("Update pref", b.toString());

        tgButton = (ToggleButton)findViewById(R.id.toggleButton);
        tgButton.setChecked(mBool);




        final boolean mBool1 = servicePrefs.getBoolean("myservice", false);
            final Boolean c = mBool1;
        Log.e("Update pref", c.toString());


        tgButton=(ToggleButton)findViewById(R.id.toggleButton);
        tgButton.setOnClickListener(new OnClickListener()

      {

            @Override
            public void onClick(View v) 
                  {
                // TODO Auto-generated method stub

                if(tgButton.isChecked())
                {
                    startService(new Intent(Toggle_Activity.this , MyService.class));
                    System.out.println("Service is started in togglr button");

                }
                else
                {   

                    stopService(new Intent(Toggle_Activity.this,MyService.class));
                    System.out.println("Service is stopped in togglr button");

                }
            }
        });


    }

}

Answer 1

在第一个活动中，你将startService（new Intent（this，MyService.class））放在onresume中来自oncreate

Answer 2

我认为这是最好的方式。我基本上使用共享首选项和侦听器将我的切换按钮和我的服务链接在一起。我称之为共享偏好＆＃34; service_running＆＃34;然后在活动onCreate()方法中实现我的听众，其中包含切换按钮（在本例中为MainActivity。

在我onCreate()继承人的所作所为：

    // set toggle button based on service running
    final ToggleButton toggle = (ToggleButton)findViewById(R.id.toggleButton);
    toggle.setChecked(serviceRunning(SendService.class));
    toggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        public void onCheckedChanged (CompoundButton buttonView, boolean isChecked) {
            if (isChecked) {
                startSendService();
            }
            else {
                stopSendService();
            }
        }
    });

    // set shared pref listener for toggle
    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
    SharedPreferences.OnSharedPreferenceChangeListener myPrefListner = new SharedPreferences.OnSharedPreferenceChangeListener(){
        public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
            if (key.equals("service_running")) {
                toggle.setChecked(prefs.getBoolean("service_running", false));
            }
        }
    };
    prefs.registerOnSharedPreferenceChangeListener(myPrefListner);

startSendService()和stopSendService()只是启动或停止我的服务，具体取决于它是否正在运行且是否具有正确的应用权限。

下面是检查服务是否正在运行的方法（归功于this thread中的@geekQ）：

private boolean serviceRunning (Class<?> serviceClass) {
    // check if a service class is currently running
    ActivityManager manager = (ActivityManager)getSystemService(Context.ACTIVITY_SERVICE);

    for (ActivityManager.RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
        if (serviceClass.getName().equals(service.service.getClassName())) {
            return true;
        }
    }

    return false;
}

然后在我的服务中，在onStartCommand（）中我刚刚将共享首选项更改为true，并在onDestroy（）中将其更改为false。

唯一需要注意的是，您必须在偏好设置屏幕中隐藏此共享偏好设置，可以通过以下方式完成：

getPreferenceScreen().removePreference(findPreference("service_running"));

如何在Android中使用切换按钮停止后台服务？

2 个答案: