android service

Service基本用法

新建一个MyService类集成Service，重写Service的onCreate()、onStartCommand()和onDestroy()函数。

public class MyService extends Service {
    private final static String TAG = "MyService";
    
    @Override
    public void onCreate() {
        super.onCreate();
        Log.d(TAG, "onCreate");
    }
    
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d(TAG, "onStartCommand");
        return super.onStartCommand(intent, flags, startId);
    }

    
    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "onDestroy");
    }
    
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

在AndroidManifest.xml中注册service

<service android:name=".MyService"></service>

在activity_main.xml中添加两个button用于启动和停止service

<Button
        android:id="@+id/start"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="80dp"
        android:layout_marginTop="148dp"
        android:text="start"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/stop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="220dp"
        android:layout_marginTop="72dp"
        android:text="stop"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

编辑activity添加service启动停止逻辑。使用Context.startService()启动服务，使用Context.stopService()停止服务

Button btnStart=(Button)findViewById(R.id.start);
        btnStart.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(v.getContext(),MyService.class);
                startService(intent);
            }
        });
        Button btnStop=(Button)findViewById(R.id.stop);
        btnStop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(v.getContext(),MyService.class);
                stopService(intent);
            }
        });

　　

Service和Activity绑定

修改onBind函数。添加MyBinder类

private final static String TAG = "MyService";
    private MyBinder myBinder = new MyBinder();

    @Override
    public void onCreate() {
        super.onCreate();
        Log.d(TAG, "onCreate");
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d(TAG, "onStartCommand");
        return super.onStartCommand(intent, flags, startId);
    }


    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "onDestroy");
    }

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

    class MyBinder extends Binder {
        public void startBinder(){
            Log.d(TAG,"startBinder");
        }
    }

修改activity_main.xml文件添加绑定和移除绑定按钮

<Button
        android:id="@+id/start"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="80dp"
        android:layout_marginTop="148dp"
        android:text="start"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/stop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="220dp"
        android:layout_marginTop="72dp"
        android:text="stop"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/binder"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="binder"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/unBinder"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="124dp"
        android:layout_marginTop="16dp"
        android:text="unBinder"
        app:layout_constraintStart_toStartOf="@+id/binder"
        app:layout_constraintTop_toTopOf="parent" />

添加绑定和移除绑定按钮事件

ServiceConnection serviceConnection=new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            MyService.MyBinder myBinder=(MyService.MyBinder)service;
            myBinder.startBinder();
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {

        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btnStart=(Button)findViewById(R.id.start);
        btnStart.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(v.getContext(),MyService.class);
                startService(intent);
            }
        });
        Button btnStop=(Button)findViewById(R.id.stop);
        btnStop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(v.getContext(),MyService.class);
                stopService(intent);
            }
        });
        Button btnBinder=(Button)findViewById(R.id.binder);
        btnBinder.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(v.getContext(),MyService.class);
                bindService(intent,serviceConnection,BIND_AUTO_CREATE);
            }
        });
        Button btnUnBinder=(Button)findViewById(R.id.unBinder);
        btnUnBinder.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                unbindService(serviceConnection);
            }
        });
    }

当服务绑定activity后，必须移除绑定并停止服务以后服务才会被真正销毁