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

java 复制代码

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

xml 复制代码

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

2、Activity Layout

activity_bind_and_unbind_service_test1.xml

xml 复制代码

<?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>

activity_bind_and_unbind_service_test2.xml

xml 复制代码

<?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

BindAndUnbindServiceTest1Activity.java

java 复制代码

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));
        });
    }
}

BindAndUnbindServiceTest2Activity.java

java 复制代码

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

在 BindAndUnbindServiceTest1Activity 中，点击【绑定服务】按钮，输出结果

onCreate
onBind
onServiceConnected
在 BindAndUnbindServiceTest1Activity 中，点击【跳转】按钮，跳转到 BindAndUnbindServiceTest2Activity
在 BindAndUnbindServiceTest2Activity 中，点击【绑定服务】按钮，输出结果

onServiceConnected
在 BindAndUnbindServiceTest2Activity 中，点击【解绑服务】按钮，输出结果

无内容输出
在 BindAndUnbindServiceTest2Activity 中，点击【回退】按钮，回退到 BindAndUnbindServiceTest1Activity
在 BindAndUnbindServiceTest1Activity 中，点击【解绑服务】按钮，输出结果

onUnbind
onDestroy

Service 与 Activity 双向交互

1、演示

（1）Service

ServiceCallback.java

java 复制代码

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

CommunicateService.java

java 复制代码

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

xml 复制代码

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

（2）Activity

activity_communicate_service_test.xml

xml 复制代码

<?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

java 复制代码

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

方向	方式	关键代码
Activity → Service	直接调用 Service 方法	`communicateService.startLongTask()`
Service → Activity	通过回调接口	`serviceCallback.onTaskComplete(result)`