मुझे किसी गतिविधि और सेवा के बीच संदेश भेजने का कोई उदाहरण नहीं मिल सकता है, और मैंने इसे पूरा करने में कई घंटे बिताए हैं। यहाँ दूसरों के लिए संदर्भ के लिए एक उदाहरण परियोजना है।
यह उदाहरण आपको किसी सेवा को सीधे शुरू या बंद करने की अनुमति देता है, और सेवा से अलग से बाँध / unbind करता है। जब सेवा चल रही होती है, तो यह 10 हर्ट्ज पर एक नंबर बढ़ाता है। यदि गतिविधि के लिए बाध्य है Service
, तो यह वर्तमान मूल्य प्रदर्शित करेगा। डेटा को एक पूर्णांक के रूप में और एक स्ट्रिंग के रूप में स्थानांतरित किया जाता है ताकि आप देख सकें कि कैसे दो अलग-अलग तरीके हैं। सेवा में संदेश भेजने के लिए गतिविधि में बटन भी हैं (वेतन वृद्धि मूल्य में परिवर्तन)।
स्क्रीनशॉट:
AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.exampleservice"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".MainActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".MyService"></service>
</application>
<uses-sdk android:minSdkVersion="8" />
</manifest>
रेस \ मूल्यों \ strings.xml:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">ExampleService</string>
<string name="service_started">Example Service started</string>
<string name="service_label">Example Service Label</string>
</resources>
रेस \ लेआउट \ main.xml:
<RelativeLayout
android:id="@+id/RelativeLayout01"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<Button
android:id="@+id/btnStart"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Start Service" >
</Button>
<Button
android:id="@+id/btnStop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="Stop Service" >
</Button>
</RelativeLayout>
<RelativeLayout
android:id="@+id/RelativeLayout02"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<Button
android:id="@+id/btnBind"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Bind to Service" >
</Button>
<Button
android:id="@+id/btnUnbind"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="Unbind from Service" >
</Button>
</RelativeLayout>
<TextView
android:id="@+id/textStatus"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Status Goes Here"
android:textSize="24sp" />
<TextView
android:id="@+id/textIntValue"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Integer Value Goes Here"
android:textSize="24sp" />
<TextView
android:id="@+id/textStrValue"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="String Value Goes Here"
android:textSize="24sp" />
<RelativeLayout
android:id="@+id/RelativeLayout03"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<Button
android:id="@+id/btnUpby1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Increment by 1" >
</Button>
<Button
android:id="@+id/btnUpby10"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="Increment by 10" >
</Button>
</RelativeLayout>
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;
}
}
android:process=:myservicename
केservice
टैग के लिए विशेषता को अपने घोषणापत्र में रखते हैं। जैसे:,<service android:name="sname" android:process=":myservicename" />
तो यह आपकी सेवा को एक अलग प्रक्रिया के रूप में चलाएगा - इस प्रकार एक अलग सूत्र में। इसका मतलब है, कि सेवा द्वारा किसी भी भारी गणना / लंबे अनुरोध ने आपके यूआई धागे को लटका नहीं दिया है।