Android Service（二）Service的两种启动方式

• • 一、startService
  • 二、bindService

效果图：需要配合图2查看效果，往下翻
图1

图2

图3

MainActivity.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private Button btnStart,btnStop;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        btnStart = findViewById(R.id.btn_start);
        btnStop = findViewById(R.id.btn_stop);
        btnStart.setOnClickListener(this);
        btnStop.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.btn_start:
                Intent intent1 = new Intent(MainActivity.this,MyService.class);
                startService(intent1);
                break;
            case R.id.btn_stop:
                Intent intent2 = new Intent(MainActivity.this,MyService.class);
                stopService(intent2);
                break;
        }
    }
}

MyService.java

public class MyService extends Service {

    public MyService() {
    }

    //创建服务时，系统会调用此方法。如果服务已经运行，则不会调用此方法，所以该方法只调用一次
    @Override
    public void onCreate() {
        super.onCreate();
        Log.i("Service","onCreate");
    }

    //当组件调用 startService()请求启动服务时，系统将调用此方法
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.i("Service","onStartCommand");
        return super.onStartCommand(intent, flags, startId);
    }

    //当服务不再使用且将被销毁时，比如：组件调用 stopService()，系统将会调用此方法
    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.i("Service","onDestroy");
    }

    //源码：将通信通道返回给服务
    //将客户端和服务端进行绑定，若不能绑定，则返回null
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

AndroidManifest.xml

adtivity_main.xml

源码：
链接：https://pan.baidu.com/s/112ub3K6HxtJ7YWjTveaV_A
提取码：dljv

效果图：需要配合图2查看效果，往下翻
图1

图2

图3

MyService.java

public class MyService extends Service {
    private MyBinder myBinder;
    private int num = 0;            //数字
    private Timer timer;
    private TimerTask timerTask;


    public MyService() {
    }

    //创建服务时，系统会调用此方法。如果服务已经运行，则不会调用此方法，所以该方法只调用一次
    @Override
    public void onCreate() {
        super.onCreate();
        Log.i("MyBindService","onCreate");
        myBinder = new MyBinder();
        //定时器
        timer = new Timer();
        //定时器任务
        timerTask = new TimerTask() {
            @Override
            public void run() {
                    num++;
            }
        };
        //先立即执行 timerTask里的任务，然后每个两秒再继续去执行 timerTask里的任务。
        timer.schedule(timerTask,0,2000);
    }

    //将客户端和服务端进行通信绑定
    //return IBinder对象，这个对象所指的就是客户端和服务端的通信通道
    @Override
    public IBinder onBind(Intent intent) {
        Toast.makeText(this,"绑定",Toast.LENGTH_SHORT).show();
        Log.i("MyBindService","onBind");
        return myBinder;
    }

    //解除绑定
    @Override
    public boolean onUnbind(Intent intent) {
        Log.i("MyBindService","onUnbind");
        return super.onUnbind(intent);
    }

    //销毁
    @Override
    public void onDestroy() {
        super.onDestroy();
        timer.cancel();
        timerTask.cancel();
        Log.i("MyBindService","onDestroy");
    }

    public class MyBinder extends Binder{
        public int getNum(){
            return num;
        }
    }

}

AndroidManifest.xml

MainActivity.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button btnStart,btnGetValue,btnStop;
    private MyService.MyBinder myBinder;        //创建 Binder 对象  ->通信管道（通信媒介）
    private MyConnection myConnection;          //创建 ServiceConnection 对象   ->连接服务

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
        myConnection = new MyConnection();
    }

    private void init() {
        btnStart = findViewById(R.id.btn_start);
        btnGetValue = findViewById(R.id.btn_get_value);
        btnStop = findViewById(R.id.btn_stop);
        btnStart.setOnClickListener(this);
        btnGetValue.setOnClickListener(this);
        btnStop.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.btn_start:
                Intent intent = new Intent(MainActivity.this,MyService.class);
                //意图，服务连接，绑定方式
                bindService(intent,myConnection, Service.BIND_AUTO_CREATE);
                break;
            case R.id.btn_get_value:
                android.util.Log.i("MyBindService","MyBinder 还存在吗？ = " + myBinder);
                if (myBinder!=null)
                    Toast.makeText(MainActivity.this,String.valueOf(myBinder.getNum()),Toast.LENGTH_SHORT).show();
                else
                    Toast.makeText(MainActivity.this,"不好意思，服务已断开，请重新连接",Toast.LENGTH_SHORT).show();
                break;
            case R.id.btn_stop:
                //解除绑定
                unbindService(myConnection);
                myBinder = null;
                break;
        }
    }



    public class MyConnection implements ServiceConnection {

        //服务连接
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            myBinder = (MyService.MyBinder) service;
            Log.i("MyBindService","onServiceConnected");
        }

        //服务断开连接
        //只会在出现异常时才会被调用
        @Override
        public void onServiceDisconnected(ComponentName name) {
            Log.i("MyBindService","onServiceDisconnected");
        }
    }
}

activity_main.xml

源码：
链接：https://pan.baidu.com/s/1cid7MKWdgeIXe2Hz7Pef7w
提取码：rjqw