service的使用
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2.
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src\com.exampleservice\MainActivity.java:
package com.exampleservice;import android.app.Activity;import android.content.ComponentName;import android.content.Context;import android.content.Intent;import android.content.ServiceConnection;import android.os.Bundle;import android.os.Handler;import android.os.IBinder;import android.os.Message;import android.os.Messenger;import android.os.RemoteException;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;public class MainActivity extends Activity { Button btnStart, btnStop, btnBind, btnUnbind, btnUpby1, btnUpby10; TextView textStatus, textIntValue, textStrValue; Messenger mService = null; boolean mIsBound; final Messenger mMessenger = new Messenger(new IncomingHandler()); class IncomingHandler extends Handler { @Override public void handleMessage(Message msg) { switch (msg.what) { case MyService.MSG_SET_INT_VALUE: textIntValue.setText("Int Message: " + msg.arg1); break; case MyService.MSG_SET_STRING_VALUE: String str1 = msg.getData().getString("str1"); textStrValue.setText("Str Message: " + str1); break; default: super.handleMessage(msg); } } } private ServiceConnection mConnection = new ServiceConnection() { public void onServiceConnected(ComponentName className, IBinder service) { mService = new Messenger(service); textStatus.setText("Attached."); try { Message msg = Message.obtain(null, MyService.MSG_REGISTER_CLIENT); msg.replyTo = mMessenger; mService.send(msg); } catch (RemoteException e) { // In this case the service has crashed before we could even do anything with it } } public void onServiceDisconnected(ComponentName className) { // This is called when the connection with the service has been unexpectedly disconnected - process crashed. mService = null; textStatus.setText("Disconnected."); } }; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); btnStart = (Button)findViewById(R.id.btnStart); btnStop = (Button)findViewById(R.id.btnStop); btnBind = (Button)findViewById(R.id.btnBind); btnUnbind = (Button)findViewById(R.id.btnUnbind); textStatus = (TextView)findViewById(R.id.textStatus); textIntValue = (TextView)findViewById(R.id.textIntValue); textStrValue = (TextView)findViewById(R.id.textStrValue); btnUpby1 = (Button)findViewById(R.id.btnUpby1); btnUpby10 = (Button)findViewById(R.id.btnUpby10); btnStart.setOnClickListener(btnStartListener); btnStop.setOnClickListener(btnStopListener); btnBind.setOnClickListener(btnBindListener); btnUnbind.setOnClickListener(btnUnbindListener); btnUpby1.setOnClickListener(btnUpby1Listener); btnUpby10.setOnClickListener(btnUpby10Listener); restoreMe(savedInstanceState); CheckIfServiceIsRunning(); } @Override protected void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); outState.putString("textStatus", textStatus.getText().toString()); outState.putString("textIntValue", textIntValue.getText().toString()); outState.putString("textStrValue", textStrValue.getText().toString()); } private void restoreMe(Bundle state) { if (state!=null) { textStatus.setText(state.getString("textStatus")); textIntValue.setText(state.getString("textIntValue")); textStrValue.setText(state.getString("textStrValue")); } } private void CheckIfServiceIsRunning() { //If the service is running when the activity starts, we want to automatically bind to it. if (MyService.isRunning()) { doBindService(); } } private OnClickListener btnStartListener = new OnClickListener() { public void onClick(View v){ startService(new Intent(MainActivity.this, MyService.class)); } }; private OnClickListener btnStopListener = new OnClickListener() { public void onClick(View v){ doUnbindService(); stopService(new Intent(MainActivity.this, MyService.class)); } }; private OnClickListener btnBindListener = new OnClickListener() { public void onClick(View v){ doBindService(); } }; private OnClickListener btnUnbindListener = new OnClickListener() { public void onClick(View v){ doUnbindService(); } }; private OnClickListener btnUpby1Listener = new OnClickListener() { public void onClick(View v){ sendMessageToService(1); } }; private OnClickListener btnUpby10Listener = new OnClickListener() { public void onClick(View v){ sendMessageToService(10); } }; private void sendMessageToService(int intvaluetosend) { if (mIsBound) { if (mService != null) { try { Message msg = Message.obtain(null, MyService.MSG_SET_INT_VALUE, intvaluetosend, 0); msg.replyTo = mMessenger; mService.send(msg); } catch (RemoteException e) { } } } } void doBindService() { bindService(new Intent(this, MyService.class), mConnection, Context.BIND_AUTO_CREATE); mIsBound = true; textStatus.setText("Binding."); } void doUnbindService() { if (mIsBound) { // If we have received the service, and hence registered with it, then now is the time to unregister. if (mService != null) { try { Message msg = Message.obtain(null, MyService.MSG_UNREGISTER_CLIENT); msg.replyTo = mMessenger; mService.send(msg); } catch (RemoteException e) { // There is nothing special we need to do if the service has crashed. } } // Detach our existing connection. unbindService(mConnection); mIsBound = false; textStatus.setText("Unbinding."); } } @Override protected void onDestroy() { super.onDestroy(); try { doUnbindService(); } catch (Throwable t) { Log.e("MainActivity", "Failed to unbind from the service", t); } }}src\com.exampleservice\MyService.java:
package com.exampleservice;import java.util.ArrayList;import java.util.Timer;import java.util.TimerTask;import android.app.Notification;import android.app.NotificationManager;import android.app.PendingIntent;import android.app.Service;import android.content.Intent;import android.os.Bundle;import android.os.Handler;import android.os.IBinder;import android.os.Message;import android.os.Messenger;import android.os.RemoteException;import android.util.Log;public class MyService extends Service { private NotificationManager nm; private Timer timer = new Timer(); private int counter = 0, incrementby = 1; private static boolean isRunning = false; ArrayList<Messenger> mClients = new ArrayList<Messenger>(); // Keeps track of all current registered clients. int mValue = 0; // Holds last value set by a client. static final int MSG_REGISTER_CLIENT = 1; static final int MSG_UNREGISTER_CLIENT = 2; static final int MSG_SET_INT_VALUE = 3; static final int MSG_SET_STRING_VALUE = 4; final Messenger mMessenger = new Messenger(new IncomingHandler()); // Target we publish for clients to send messages to IncomingHandler. @Override public IBinder onBind(Intent intent) { return mMessenger.getBinder(); } class IncomingHandler extends Handler { // Handler of incoming messages from clients. @Override public void handleMessage(Message msg) { switch (msg.what) { case MSG_REGISTER_CLIENT: mClients.add(msg.replyTo); break; case MSG_UNREGISTER_CLIENT: mClients.remove(msg.replyTo); break; case MSG_SET_INT_VALUE: incrementby = msg.arg1; break; default: super.handleMessage(msg); } } } private void sendMessageToUI(int intvaluetosend) { for (int i=mClients.size()-1; i>=0; i--) { try { // Send data as an Integer mClients.get(i).send(Message.obtain(null, MSG_SET_INT_VALUE, intvaluetosend, 0)); //Send data as a String Bundle b = new Bundle(); b.putString("str1", "ab" + intvaluetosend + "cd"); Message msg = Message.obtain(null, MSG_SET_STRING_VALUE); msg.setData(b); mClients.get(i).send(msg); } catch (RemoteException e) { // The client is dead. Remove it from the list; we are going through the list from back to front so this is safe to do inside the loop. mClients.remove(i); } } } @Override public void onCreate() { super.onCreate(); Log.i("MyService", "Service Started."); showNotification(); timer.scheduleAtFixedRate(new TimerTask(){ public void run() {onTimerTick();}}, 0, 100L); isRunning = true; } private void showNotification() { nm = (NotificationManager)getSystemService(NOTIFICATION_SERVICE); // In this sample, we'll use the same text for the ticker and the expanded notification CharSequence text = getText(R.string.service_started); // Set the icon, scrolling text and timestamp Notification notification = new Notification(R.drawable.icon, text, System.currentTimeMillis()); // The PendingIntent to launch our activity if the user selects this notification PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, MainActivity.class), 0); // Set the info for the views that show in the notification panel. notification.setLatestEventInfo(this, getText(R.string.service_label), text, contentIntent); // Send the notification. // We use a layout id because it is a unique number. We use it later to cancel. nm.notify(R.string.service_started, notification); } @Override public int onStartCommand(Intent intent, int flags, int startId) { Log.i("MyService", "Received start id " + startId + ": " + intent); return START_STICKY; // run until explicitly stopped. } public static boolean isRunning() { return isRunning; } private void onTimerTick() { Log.i("TimerTick", "Timer doing work." + counter); try { counter += incrementby; sendMessageToUI(counter); } catch (Throwable t) { //you should always ultimately catch all exceptions in timer tasks. Log.e("TimerTick", "Timer Tick Failed.", t); } } @Override public void onDestroy() { super.onDestroy(); if (timer != null) {timer.cancel();} counter=0; nm.cancel(R.string.service_started); // Cancel the persistent notification. Log.i("MyService", "Service Stopped."); isRunning = false; }}
