切换按钮以启动服务答案

【问题标题】：toggle button to start a service切换按钮以启动服务
【发布时间】：2019-03-17 04:52:49
【问题描述】：

我制作了一个切换按钮，我需要使用它来启动和停止服务。 该服务是在 WatcherService.java 中定义的，但我无法调用它。请帮助我。这是我的 MainActivity.java 代码

**ToggleButton toggle = (ToggleButton) findViewById(R.id.togglebutton);
toggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        if (isChecked) {
            // what code is to be written here ? 
        } else {
            //  what code is to be written here ?
        }
    }
});**

【问题讨论】：

标签： java android eclipse

【解决方案1】：

要启动服务，您可以使用以下代码：

                        Intent service = new Intent(buttonView.getContext(), WatcherService.java);
                        if (isChecked) {
                            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                                buttonView.getContext().startForegroundService(service);
                            }else{
                                buttonView.getContext().startService(service);
                            }
                        } else {
                            buttonView.getContext().stopService(service);
                        }

注意，在 Android Oreo 中，启动一个服务会有一点不同。你可以在这里阅读更多：https://developer.android.com/about/versions/oreo/background

【讨论】：

【解决方案2】：

所以基本上你需要在切换检查时启动服务并在切换关闭时停止服务所以你的逻辑应该是这样的：

    toggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    Intent service = new Intent(buttonView.getContext(), WatcherService.java);
                    if (isChecked) {
                         // start Service
                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                           startForegroundService(service);
                        }else{
                           startService(service);
                        }
                    } else {
                       // stop service
                        stopService(service);
                    }
                }
            });

如果此代码在 MainActivity 中则可以，否则添加 context.startService 或 context.stopService

【讨论】：

【解决方案3】：

这是一个完整的例子。希望对您有所帮助！

要启动或停止服务，你们都调用startService，所以传递一个操作（“START_SERVICE”/“STOP_SERVICE”），以便在您的 WatcherService onStartCommand()，您可以决定启动或停止您的服务

toggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            if (isChecked) {
                // Start service
                Intent intentService = new Intent(this, WatcherService.class);
                intentService.setAction("START_SERVICE");
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                    this.startForegroundService(intentService);
                } else {
                    this.startService(intentService);
                }
            } else {
                Intent intentService = new Intent(this, WatcherService.class);
                intentService.setAction("STOP_SERVICE");
                Log.v(">>>", "Try to stop service");
                startService(intentService);
            }
        }
    });

请注意，从 Android 8 开始，您必须 startForegroundService（使用通知）。你可以看到更多关于前景和背景的信息服务于Foreground & Background Service

public class WatcherService extends Service {

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

    if (intent != null && intent.getAction() != null) {
        if (intent.getAction().equals("START_SERVICE")) {
            Log.v(">>>", "Start service");

        } else if (intent.getAction().equals("STOP_SERVICE") {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                stopForeground(true);
                stopSelf();
                Log.v(">>>", "Stop foreground service");
            } else {
                stopSelf();
                Log.v(">>>", "Stop background service");
            }

        }
    }

    return START_STICKY;
}


/**
 * Start foreground service for Android 8+
 */
@Override
public void onCreate() {
    super.onCreate();


    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        String channelId = Build.VERSION.SDK_INT >= Build.VERSION_CODES.O ? createNotificationChannel(notificationManager) : "";
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, channelId);
        Notification notification = notificationBuilder.setOngoing(true)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle("Title")
                .setPriority(PRIORITY_MIN)
                .setCategory(NotificationCompat.CATEGORY_SERVICE)
                .build();

        startForeground(101, notification);
    }
}

@RequiresApi(Build.VERSION_CODES.O)
private String createNotificationChannel(NotificationManager notificationManager) {
    String channelId = "channel_id_01";
    String channelName = "chanel_name";
    NotificationChannel channel = new NotificationChannel(channelId, channelName, NotificationManager.IMPORTANCE_HIGH);
    // omitted the LED color
    channel.setImportance(NotificationManager.IMPORTANCE_NONE);
    channel.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
    notificationManager.createNotificationChannel(channel);
    return channelId;
}

.......
}

【讨论】：