Service学习总结

下面是平时学习中对Service的一些总结

http://note.youdao.com/yws/public/redirect/share?id=703f6407ff7a08bccb8ccd8cc7a1a107&type=false

http://note.youdao.com/yws/public/redirect/share?id=f5ce1c8a6fae5cc0335c4dbb946fae84&type=false

Messenger使用代码：

1.先创建一个远程服务

public class MessengerService extends Service {    private static final int MSG_SUM = 0x110;    public MessengerService() {    }    Messenger messenger = new Messenger(new Handler(){        @Override        public void handleMessage(Message msgfromclient) {            super.handleMessage(msgfromclient);            //根据客户端发过来的消息创建一个message对象            Message msgtoclient = Message.obtain(msgfromclient);            switch (msgfromclient.what){                case MSG_SUM:                    msgtoclient.what = MSG_SUM;                    try {                        Thread.sleep(2000);                        msgtoclient.arg2 = msgfromclient.arg1 + msgfromclient.arg2;                        //向客户端发送消息，replyto方法获得一个messenger对象                        msgfromclient.replyTo.send(msgtoclient);                    }catch (RemoteException e) {                            e.printStackTrace();                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                    break;            }        }    });    @Override    public IBinder onBind(Intent intent) {        //获得binder对象        return messenger.getBinder();    }}

同时要在清单文件注册，注意加上动作

  <service            android:name=".MessengerService"            android:enabled="true"            android:exported="true">            <intent-filter>                <action android:name="com.lxn.add"/>            </intent-filter>        </service>

然后我们创建客户端，

   private static final String TAG = "MainActivity";    private static final int MSG_SUM = 0x110;    boolean isBound = false;    private Button mBtnAdd;    private LinearLayout mLyContainer;    //显示连接状态    private TextView mTvState;    private int mA;    private Messenger mService;    private Messenger messenger = new Messenger(new Handler(){        @Override        public void handleMessage(Message msgFromServer) {            super.handleMessage(msgFromServer);            switch (msgFromServer.what){                case MSG_SUM:                    TextView tv = (TextView) mLyContainer.findViewById(msgFromServer.arg1);                    tv.setText(tv.getText() + "=>" + msgFromServer.arg2);                    break;            }        }    });    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mTvState = (TextView) findViewById(R.id.id_tv_callback);        mBtnAdd = (Button) findViewById(R.id.id_btn_add);        mLyContainer = (LinearLayout) findViewById(R.id.id_ll_container);        invokeBindService();        mBtnAdd.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                int a = mA++;                int b = (int) (Math.random()*100);                TextView textview = new TextView(MainActivity.this);                textview.setText(a + " + " + b + " = caculating ...");                textview.setId(a);                mLyContainer.addView(textview);                Message msgfromclient = Message.obtain(null, MSG_SUM, a, b);                msgfromclient.replyTo = messenger;                if(isBound){                    try {                        mService.send(msgfromclient);//向服务器发消息                    } catch (RemoteException e) {                        e.printStackTrace();                    }                }            }        });    }    private void invokeBindService() {        Intent intent = new Intent();        //绑定服务，远程服务必须指定action        intent.setAction("com.lxn.add");        bindService(intent,conn,BIND_AUTO_CREATE);    }    ServiceConnection conn = new ServiceConnection() {        @Override        public void onServiceConnected(ComponentName name, IBinder service) {            mService = new Messenger(service);            isBound = true;            mTvState.setText("connected");        }        @Override        public void onServiceDisconnected(ComponentName name) {            isBound  = false;            mService = null;            mTvState.setText("disconnected");        }    };    @Override    protected void onDestroy() {        super.onDestroy();        if(isBound){            unbindService(conn);            isBound = false;        }    }}