发布于 2016-02-22 02:27:35 | 105 次阅读 | 评论: 0 | 来源: 网友投递
Android移动端操作系统
Android是一种基于Linux的自由及开放源代码的操作系统,主要使用于移动设备,如智能手机和平板电脑,由Google公司和开放手机联盟领导及开发。尚未有统一中文名称,中国大陆地区较多人使用“安卓”或“安致”。
public abstract class IntentService extends Service {
private volatile Looper mServiceLooper;
private volatile ServiceHandler mServiceHandler; //一个Handler封装了Looper对象
private String mName;
private boolean mRedelivery;
private final class ServiceHandler extends Handler {
public ServiceHandler(Looper looper) {
super(looper);
}
@Override
public void handleMessage(Message msg) {
onHandleIntent((Intent)msg.obj);
stopSelf(msg.arg1);
}
}
public IntentService(String name) { //构造方法,需要提供一个name作为标识
super();
mName = name;
}
onStartCommand(Intent, int, int)} will return
Service#START_REDELIVER_INTENT}, so if this process dies before
onHandleIntent(Intent)} returns, the process will be restarted
onStartCommand(Intent, int, int)} will return
Service#START_NOT_STICKY}, and if the process dies
public void setIntentRedelivery(boolean enabled) {
mRedelivery = enabled;
}
@Override
public void onCreate() { //这里重写父类Service的创建,主要是构造一个线程
super.onCreate();
HandlerThread thread = new HandlerThread("IntentService[" + mName + "]");
thread.start();
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
}
@Override
public void onStart(Intent intent, int startId) { //Android 2.0以前的Service启动参数控制
Message msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
msg.obj = intent;
mServiceHandler.sendMessage(msg);
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) { //Android 2.0以后的服务启动参数
onStart(intent, startId);
return mRedelivery ? START_REDELIVER_INTENT : START_NOT_STICKY;
}
@Override
public void onDestroy() { //服务摧毁的时候Looper一定要释放掉,这点很重要。
mServiceLooper.quit();
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
protected abstract void onHandleIntent(Intent intent);
}