Android Service - Service 生命周期变化、Service 与 Activity 双向交互

Service 生命周期变化

1、Service

• BindAndUnbindLifecycleService.java

public class BindAndUnbindLifecycleService extends Service {

public static final String TAG = BindAndUnbindLifecycleService.class.getSimpleName();

private IBinder LocalBinder = new BindAndUnbindLifecycleService.BindAndUnbindLifecycleServiceBinder();

public class BindAndUnbindLifecycleServiceBinder extends Binder {
public BindAndUnbindLifecycleService getService() {
return BindAndUnbindLifecycleService.this;
}
}

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

Log.i(TAG, "onCreate");
}

@Nullable
@Override
public IBinder onBind(Intent intent) {
Log.i(TAG, "onBind");

return LocalBinder;
}

@Override
public boolean onUnbind(Intent intent) {
Log.i(TAG, "onUnbind");

return super.onUnbind(intent);
}

@Override
public void onDestroy() {
super.onDestroy();

Log.i(TAG, "onDestroy");
}
}

• AndroidManifest.xml

<service android:name=".myservice.BindAndUnbindLifecycleService" />

2、Activity Layout

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".BindAndUnbindServiceTest1Activity">

<Button
android:id="@+id/btn_bind"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="绑定服务"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />

<Button
android:id="@+id/btn_unbind"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="解绑服务"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/btn_bind" />

<Button
android:id="@+id/btn_go"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="跳转"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".BindAndUnbindServiceTest2Activity">

<Button
android:id="@+id/btn_bind"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="绑定服务"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />

<Button
android:id="@+id/btn_unbind"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="解绑服务"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/btn_bind" />

<Button
android:id="@+id/btn_back"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="回退"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

3、Activity Code

public class BindAndUnbindServiceTest1Activity extends AppCompatActivity {

public static final String TAG = BindAndUnbindServiceTest1Activity.class.getSimpleName();

private Button btnBind;
private Button btnUnbind;
private Button btnGo;

private BindAndUnbindLifecycleService bindAndUnbindLifecycleService;

private ServiceConnection serviceConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
Log.i(TAG, "onServiceConnected");

BindAndUnbindLifecycleService.BindAndUnbindLifecycleServiceBinder bindAndUnbindLifecycleServiceBinder = (BindAndUnbindLifecycleService.BindAndUnbindLifecycleServiceBinder) service;
BindAndUnbindLifecycleService bindAndUnbindLifecycleService = bindAndUnbindLifecycleServiceBinder.getService();
}

@Override
public void onServiceDisconnected(ComponentName name) {
Log.i(TAG, "onServiceDisconnected");
}
};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
EdgeToEdge.enable(this);
setContentView(R.layout.activity_bind_and_unbind_service_test1);
ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
return insets;
});

btnBind = findViewById(R.id.btn_bind);
btnUnbind = findViewById(R.id.btn_unbind);
btnGo = findViewById(R.id.btn_go);

btnBind.setOnClickListener(v -> {
bindService(new Intent(this, BindAndUnbindLifecycleService.class), serviceConnection, Context.BIND_AUTO_CREATE);
});

btnUnbind.setOnClickListener(v -> {
unbindService(serviceConnection);
});

btnGo.setOnClickListener(v -> {
startActivity(new Intent(this, BindAndUnbindServiceTest2Activity.class));
});
}
}

public class BindAndUnbindServiceTest2Activity extends AppCompatActivity {

public static final String TAG = BindAndUnbindServiceTest2Activity.class.getSimpleName();

private Button btnBind;
private Button btnUnbind;
private Button btnBack;

private BindAndUnbindLifecycleService bindAndUnbindLifecycleService;

private ServiceConnection serviceConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
Log.i(TAG, "onServiceConnected");

BindAndUnbindLifecycleService.BindAndUnbindLifecycleServiceBinder bindAndUnbindLifecycleServiceBinder = (BindAndUnbindLifecycleService.BindAndUnbindLifecycleServiceBinder) service;
BindAndUnbindLifecycleService bindAndUnbindLifecycleService = bindAndUnbindLifecycleServiceBinder.getService();
}

@Override
public void onServiceDisconnected(ComponentName name) {
Log.i(TAG, "onServiceDisconnected");
}
};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
EdgeToEdge.enable(this);
setContentView(R.layout.activity_bind_and_unbind_service_test2);
ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
return insets;
});

btnBind = findViewById(R.id.btn_bind);
btnUnbind = findViewById(R.id.btn_unbind);
btnBack = findViewById(R.id.btn_back);

btnBind.setOnClickListener(v -> {
bindService(new Intent(this, BindAndUnbindLifecycleService.class), serviceConnection, Context.BIND_AUTO_CREATE);
});

btnUnbind.setOnClickListener(v -> {
unbindService(serviceConnection);
});

btnBack.setOnClickListener(v -> {
finish();
});
}
}

4、Test

onCreate
onBind
onServiceConnected

onServiceConnected

无内容输出

onUnbind
onDestroy

Service 与 Activity 双向交互

1、演示

（1）Service

• ServiceCallback.java

public interface ServiceCallback {
void onTaskComplete(int result);
}

• CommunicateService.java

public class CommunicateService extends Service {
private final IBinder binder = new CommunicateServiceBinder();
private ServiceCallback serviceCallback;
private final Handler handler = new Handler(Looper.getMainLooper());

public class CommunicateServiceBinder extends Binder {
public CommunicateService getService() {
return CommunicateService.this;
}
}

@Nullable
@Override
public IBinder onBind(Intent intent) {
return binder;
}

// 注册回调
public void setCallback(ServiceCallback serviceCallback) {
this.serviceCallback = serviceCallback;
}

public void startLongTask() {
new Thread(() -> {

// 模拟耗时操作
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}

// 发送数据
int result = 100;
if (serviceCallback != null) {
handler.post(() -> serviceCallback.onTaskComplete(result));
}
}).start();
}
}

• AndroidManifest.xml

<service android:name=".myservice.CommunicateService" />

（2）Activity

• activity_communicate_service_test.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".CommunicateServiceTestActivity">

<TextView
android:id="@+id/tv_test_content"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="无"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />

<Button
android:id="@+id/btn_execute_task"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="执行任务"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

• CommunicateServiceTestActivity.java

public class CommunicateServiceTestActivity extends AppCompatActivity {

public static final String TAG = CommunicateServiceTestActivity.class.getSimpleName();

private TextView tvTestContent;

private CommunicateService communicateService;
private boolean isBound = false;
private final ServiceCallback serviceCallback = result -> {
tvTestContent.setText(String.valueOf(result));
};
private final ServiceConnection serviceConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
Log.i(TAG, "onServiceConnected");

communicateService = ((CommunicateService.CommunicateServiceBinder) service).getService();
isBound = true;

communicateService.setCallback(serviceCallback);
}

@Override
public void onServiceDisconnected(ComponentName name) {
Log.i(TAG, "onServiceDisconnected");

isBound = false;
}
};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
EdgeToEdge.enable(this);
setContentView(R.layout.activity_communicate_service_test);
ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
return insets;
});

tvTestContent = findViewById(R.id.tv_test_content);
findViewById(R.id.btn_execute_task).setOnClickListener(v -> {
if (communicateService != null) {
communicateService.startLongTask();
}
});
}

@Override
protected void onStart() {
super.onStart();

Intent intent = new Intent(this, CommunicateService.class);
bindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);
}

@Override
protected void onStop() {
super.onStop();

if (isBound) {
if (communicateService != null) {
communicateService.setCallback(null);
}
unbindService(serviceConnection);
isBound = false;
}
}
}

2、小结