Android Service與Activity的互動
阿新 • • 發佈：2018-12-25
Android中有時候需要在Service中改變Activity的UI，或者在Activity中修改Service中的數值。首先必須使用與Activity繫結的Service，有三種方式可以實現。第一，是使用介面回撥的方式在Activty中實現Service中的介面；第二，使用廣播的方式傳遞；第三，則是用觀察者模式，在Activity中實現update方法。
使用介面回撥的方式在Activty中實現Service中的介面
package com.kkrs.serivce;
import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.util.Log;
/**
* Created by zd on 2018/12/20.
*/
//繫結的service
public class LocalService extends Service {
private final static String TAG = "LocalService";
private int count;
private boolean quit;
private Thread thread;
private LocalBinder binder = new LocalBinder();
/**
* 回撥
*/
private Callback callback;
/**
* 提供介面回撥方法
* @param callback
*/
public void setCallback(Callback callback) {
this.callback = callback;
}
/**
* 回撥介面
*
* @author lenovo
*
*/
public static interface Callback {
/**
* 得到實時更新的資料
*
* @return
*/
void getNum(int num);
}
@Override
public void onCreate() {
super.onCreate();
Log.e(TAG, "Service is invoke Created");
thread = new Thread(new Runnable() {
@Override
public void run() {
// 每間隔一秒count加1 ，直到quit為true。
while (!quit) {
try {
Thread.sleep(1000);
if(callback!=null){
/*
* 得到最新資料
*/
callback.getNum(count);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
count++;
}
}
});
thread.start();
}
public class LocalBinder extends Binder {
// 宣告一個方法，getService。（提供給客戶端呼叫）
LocalService getService() {
// 返回當前物件LocalService,這樣我們就可在客戶端端呼叫Service的公共方法了
return LocalService.this;
}
}
/**
* 公共方法
* @return
*/
public int getCount(){
return count;
}
@Override
public void onDestroy() {
Log.e(TAG, "Service is onDestroy");
this.quit = true;
super.onDestroy();
}
@Override
public boolean onUnbind(Intent intent) {
Log.e(TAG, "Service is onUnbind");
return super.onUnbind(intent);
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
Log.e(TAG, "Service is onBind");
return binder;
}
}
private ServiceConnection conn;
private LocalService mService;
@Override
protected void onCreate(Bundle savedInstanceState) {
conn = new ServiceConnection() {
/**
* 與伺服器端互動的介面方法 繫結服務的時候被回撥，在這個方法獲取繫結Service傳遞過來的IBinder物件，
* 通過這個IBinder物件，實現宿主和Service的互動。
*/
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
Log.e("MainActivity", "繫結成功呼叫：onServiceConnected");
// 獲取Binder
LocalService.LocalBinder binder = (LocalService.LocalBinder) service;
mService = binder.getService();
mService.setCallback(new LocalService.Callback(){
@Override
public void getNum(int num) {
// TODO Auto-generated method stub
Log.e("num","====num===="+num);
}
});
}
/**
* 當取消繫結的時候被回撥。但正常情況下是不被呼叫的，它的呼叫時機是當Service服務被意外銷燬時，
* 例如記憶體的資源不足時這個方法才被自動呼叫。
*/
@Override
public void onServiceDisconnected(ComponentName name) {
mService=null;
}
};
final Intent intent = new Intent(this, LocalService.class);
btnBind.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Log.e("MainActivity", "繫結呼叫：bindService");
bindService(intent, conn, Service.BIND_AUTO_CREATE);
}
});
btnUnBind.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// 解除繫結
Log.e("MainActivity", "解除繫結：bindService");
if(mService!=null) {
Log.e("MainActivity", "mService!=null");
mService = null;
unbindService(conn);
}
}
});
btnGetDatas.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (mService != null) {
// 通過繫結服務傳遞的Binder物件，獲取Service暴露出來的資料
Log.e("MainActivity", "從服務端獲取資料：" + mService.getCount());
} else {
Log.e("MainActivity", "還沒繫結呢，先繫結,無法從服務端獲取資料");
}
}
});
}
使用廣播的方式傳遞
package com.kkrs.serivce;
import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.util.Log;
import static android.content.ContentValues.TAG;
/**
* Created by zd on 2018/12/25.
*/
public class ContentService extends Service {
private Thread thread;
private boolean flag = true;
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
flag = true;
return new LocalBinder();
}
@Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();
Log.e(TAG, "Service is invoke Created");
thread = new Thread(new Runnable() {
@Override
public void run() {
// 每間隔一秒count加1 ，直到quit為true。
while (flag) {
try {
Thread.sleep(1000);
asyncSendPerson("ContentService");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
thread.start();
}
public final class LocalBinder extends Binder {
public ContentService getService() {
return ContentService.this;
}
}
public void asyncSendPerson(final String name) {
// 休息5秒，模擬非同步任務
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
//可以在子執行緒中直接傳送廣播
sendContentBroadcast(name);
}
}).start();
}
/**
* 傳送廣播
* @param name
*/
protected void sendContentBroadcast(String name) {
// TODO Auto-generated method stub
Intent intent=new Intent();
intent.setAction("com.example.servicecallback.content");
intent.putExtra("name", name);
sendBroadcast(intent);
}
}
//廣播
private ServiceReConn connRe;
private ContentReceiver mReceiver;
public class ServiceReConn implements ServiceConnection {
@Override
public void onServiceConnected(ComponentName name, IBinder binder) {
// service = ((LocalBinder) binder).getService();
}
@Override
public void onServiceDisconnected(ComponentName name) {
// TODO Auto-generated method stub
// service = null;
}
}
public class ContentReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
String name = intent.getStringExtra("name");
Person person = new Person();
person.setName(name);
Log.e("ContentReceiver",person.toString());
}
}
/**
* 註冊廣播接收者
*/
private void doRegisterReceiver() {
mReceiver=new ContentReceiver();
IntentFilter filter = new IntentFilter(
"com.example.servicecallback.content");
registerReceiver(mReceiver, filter);
}
觀察者模式
public class ObserviceService extends Service {
//被觀察者
private MyObservable mObservable;
private Thread thread;
private boolean flag = true;
@Override
public IBinder onBind(Intent arg0) {
flag = true;
return new LocalBinder();
}
@Override
public void onCreate() {
super.onCreate();
mObservable = new MyObservable();
thread = new Thread(new Runnable() {
@Override
public void run() {
// 每間隔一秒count加1 ，直到quit為true。
while (true) {
try {
Thread.sleep(1000);
asyncSendPerson("ObserviceService");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
thread.start();
}
public final class LocalBinder extends Binder {
public ObserviceService getService() {
return ObserviceService.this;
}
}
public void asyncSendPerson(final String name) {
// 休息5秒，模擬非同步任務
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.sendMessage(handler.obtainMessage(0, name));
}
}).start();
}
/**
* 新增觀察者
* @param observer
*/
public void addObserver(Observer observer) {
mObservable.addObserver(observer);
}
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
String name = (String) msg.obj;
Person person = new Person();
person.setName(name);
//通知更新
mObservable.notifyChanged(person);
}
};
public class MyObservable extends Observable {
public void notifyChanged(Object object) {
this.setChanged();
this.notifyObservers(object);
}
}
@Override
public boolean onUnbind(Intent intent) {
flag = false;
return super.onUnbind(intent);
}
@Override
public void onDestroy() {
super.onDestroy();
flag = false;
}
}
實現Observer
private ServiceConnection conn;
private LocalService mService;
//觀察這模式
private MyServiceConn connOb;
private ObserviceService observiceService;
public class MyServiceConn implements ServiceConnection {
@Override
public void onServiceConnected(ComponentName name, IBinder binder) {
observiceService = ((ObserviceService.LocalBinder) binder).getService();
//將當前activity新增為觀察者
observiceService.addObserver(MainActivity.this);
}
@Override
public void onServiceDisconnected(ComponentName name) {
observiceService = null;
}
}
@Override
public void update(Observable observable, Object o) {
Log.e("update","觀察這模式在這裡修改UI");
Person person = (Person) o;
Log.e("update",person.toString());
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
context = this;
setContentView(R.layout.activity_main);
btnBindOb = (Button)findViewById(R.id.btnBindOb);
btnUnBindOb = (Button)findViewById(R.id.btnUnBindOb);
final Intent obIntent = new Intent(context, ObserviceService.class);
connOb = new MyServiceConn();
btnBindOb.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
bindService(obIntent, connOb, Service.BIND_AUTO_CREATE);
}
});
btnUnBindOb.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(observiceService!=null) {
Log.e("MainActivity", "observiceService!=null");
observiceService = null;
unbindService(connOb);
}
}
});
}