Question

我想将服务绑定到多个活动，因此我编写了一个Application类来管理这个目标：

public class BluetoothController extends Application {
    private static BluetoothController mInstance;
    private ClientBluetoothService mService;
    protected boolean mBound = false;

    public static synchronized BluetoothController getInstance() {
        return mInstance;
    }

    @Override
    public void onCreate() {
        super.onCreate();
    }

    public void startService(){
        //start your service
        Intent intent = new Intent(this, ClientBluetoothService.class);
        bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
    }
    public void stopService(){
        //stop service
        if (mBound) {
            unbindService(mConnection);
            mBound = false;
        }
    }

    public ClientBluetoothService getService(){
        return  mService;
    }

    public boolean isBound() {
        return mBound;
    }

    private ServiceConnection mConnection = new ServiceConnection() {

        @Override
        public void onServiceConnected(ComponentName className, IBinder service) {

            ClientBluetoothService.LocalBinder binder = (ClientBluetoothService.LocalBinder) service;
            mService = binder.getSerivce();
            mBound = true;
        }

        @Override
        public void onServiceDisconnected(ComponentName arg0) {
            mBound = false;
        }
    };
}

要在活动I中访问此类，例如：

BluetoothController.getInstance().startService();

但是我有一个错误：java.lang.NullPointerException：尝试调用虚方法＆＃39; void com.gmail.krakow.michalt.myecg.BluetoothController.startService（）＆＃39;在null对象引用上。怎么解决？

Answer 1

public static synchronized BluetoothController getInstance() {
    return mInstance = new BluetoothController();
}

使用多个活动绑定服务

1 个答案: