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。