安卓 service

public class MyService extends Service {
    public MyService() {
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        //throw new UnsupportedOperationException("Not yet implemented");
        return new Binder();  //这里必须要返回一个Binder实例
    }

    // 服务启动
    @Override
    public void onStart(Intent intent, int startId) {
        super.onStart(intent, startId);
    }

    // 服务销毁
    @Override
    public void onDestroy() {
        super.onDestroy();
    }

    // 服务开始的时候 执行的方法
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        System.out.print("服务正在执行.....");
        new Thread() {
            @Override
            public void run() {
                super.run();

                while (true) {
                    System.out.print("服务正在执行....");
                    try {
                        sleep(2000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }.start();
        return super.onStartCommand(intent, flags, startId);
    }
}

public class MainActivity extends AppCompatActivity implements ServiceConnection {

    private TextView tv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.activity_main);  // 创建视图
        //setContentView(R.layout.my_layout);

        this.setContentView(R.layout.my_layout);

        // 启动服务
        findViewById(R.id.btnStartServcie).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                System.out.print("服务开始执行......");
                Intent i = new Intent(MainActivity.this, MyService.class);
                startService(i);
            }
        });
        // 停止服务
        this.findViewById(R.id.btnStopServcie).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(MainActivity.this, MyService.class);
                stopService(i);
            }
        });

        //btnBindServcie 绑定service
        this.findViewById(R.id.btnBindServcie).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(MainActivity.this, MyService.class);
                // 这里的MainActivity必须要实现ServiceConnection 重写onServiceConnected 和 onServiceDisconnected 方法
                bindService(i, MainActivity.this, Context.BIND_AUTO_CREATE);
            }
        });

        //btnBindServcie 解除绑定service
        this.findViewById(R.id.btnUnBindServcie).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(MainActivity.this, MyService.class);
                unbindService(MainActivity.this);
            }
        });

        System.out.println("onCreate");
    }

    @Override
    protected void onStart() {
        super.onStart();
        System.out.println("onStart");
    }

    @Override
    protected void onResume() {
        super.onResume();
        System.out.println("onResume");
    }

    @Override
    protected void onPause() {
        super.onPause();
        System.out.println("onPause");
    }

    @Override
    protected void onStop() {
        super.onStop();
        System.out.println("onStop");
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        System.out.println("onDestroy");
    }

    @Override
    protected void onRestart() {
        super.onRestart();
        System.out.println("onRestart");
    }

    // 服务被绑定成功后被执行
    @Override
    public void onServiceConnected(ComponentName name, IBinder service) {
        System.out.print("service connected");
    }

    // 服务被杀掉后执行
    @Override
    public void onServiceDisconnected(ComponentName name) {
        System.out.print("service DisConnected");
    }
}

这块不好理解，这个只能在以后的项目里面好好理解了。