Android 绑定类型服务---其他注意事项
以下是关于绑定的重要注意事项：
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.android.apis.app;
import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.RemoteException;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Process;
import android.os.RemoteCallbackList;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
// Need the following import to get access to the app resources, since this
// class is in a sub-package.
import com.example.android.apis.R;
/**
* This is an example of implementing an application service that runs in a
* different process than the application. Because it can be in another
* process, we must use IPC to interact with it. The
* {@link Controller} and {@link Binding} classes
* show how to interact with the service.
*
* <p>Note that most applications <strong>do not</strong> need to deal with
* the complexity shown here. If your application simply has a service
* running in its own process, the {@link LocalService} sample shows a much
* simpler way to interact with it.
*/
public class RemoteService extends Service {
/**
* This is a list of callbacks that have been registered with the
* service. Note that this is package scoped (instead of private) so
* that it can be accessed more efficiently from inner classes.
*/
final RemoteCallbackList<IRemoteServiceCallback> mCallbacks
= new RemoteCallbackList<IRemoteServiceCallback>();
int mValue = 0;
NotificationManager mNM;
@Override
public void onCreate() {
mNM = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
// Display a notification about us starting.
showNotification();
// While this service is running, it will continually increment a
// number. Send the first message that is used to perform the
// increment.
mHandler.sendEmptyMessage(REPORT_MSG);
}
@Override
public void onDestroy() {
// Cancel the persistent notification.
mNM.cancel(R.string.remote_service_started);
// Tell the user we stopped.
Toast.makeText(this, R.string.remote_service_stopped, Toast.LENGTH_SHORT).show();
// Unregister all callbacks.
mCallbacks.kill();
// Remove the next pending message to increment the counter, stopping
// the increment loop.
mHandler.removeMessages(REPORT_MSG);
}
@Override
public IBinder onBind(Intent intent) {
// Select the interface to return. If your service only implements
// a single interface, you can just return it here without checking
// the Intent.
if (IRemoteService.class.getName().equals(intent.getAction())) {
return mBinder;
}
if (ISecondary.class.getName().equals(intent.getAction())) {
return mSecondaryBinder;
}
return null;
}
/**
* The IRemoteInterface is defined through IDL
*/
private final IRemoteService.Stub mBinder = new IRemoteService.Stub() {
public void registerCallback(IRemoteServiceCallback cb) {
if (cb != null) mCallbacks.register(cb);
}
public void unregisterCallback(IRemoteServiceCallback cb) {
if (cb != null) mCallbacks.unregister(cb);
}
};
/**
* A secondary interface to the service.
*/
private final ISecondary.Stub mSecondaryBinder = new ISecondary.Stub() {
public int getPid() {
return Process.myPid();
}
public void basicTypes(int anInt, long aLong, boolean aBoolean,
float aFloat, double aDouble, String aString) {
}
};
@Override
public void onTaskRemoved(Intent rootIntent) {
Toast.makeText(this, "Task removed: " + rootIntent, Toast.LENGTH_LONG).show();
}
private static final int REPORT_MSG = 1;
/**
* Our Handler used to execute operations on the main thread. This is used
* to schedule increments of our value.
*/
private final Handler mHandler = new Handler() {
@Override public void handleMessage(Message msg) {
switch (msg.what) {
// It is time to bump the value!
case REPORT_MSG: {
// Up it goes.
int value = ++mValue;
// Broadcast to all clients the new value.
final int N = mCallbacks.beginBroadcast();
for (int i=0; i<N; i++) {
try {
mCallbacks.getBroadcastItem(i).valueChanged(value);
} catch (RemoteException e) {
// The RemoteCallbackList will take care of removing
// the dead object for us.
}
}
mCallbacks.finishBroadcast();
// Repeat every 1 second.
sendMessageDelayed(obtainMessage(REPORT_MSG), 1*1000);
} break;
default:
super.handleMessage(msg);
}
}
};
/**
* Show a notification while this service is running.
*/
private void showNotification() {
// In this sample, we'll use the same text for the ticker and the expanded notification
CharSequence text = getText(R.string.remote_service_started);
// Set the icon, scrolling text and timestamp
Notification notification = new Notification(R.drawable.stat_sample, text,
System.currentTimeMillis());
// The PendingIntent to launch our activity if the user selects this notification
PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
new Intent(this, Controller.class), 0);
// Set the info for the views that show in the notification panel.
notification.setLatestEventInfo(this, getText(R.string.remote_service_label),
text, contentIntent);
// Send the notification.
// We use a string id because it is a unique number. We use it later to cancel.
mNM.notify(R.string.remote_service_started, notification);
}
// ----------------------------------------------------------------------
/**
* <p>Example of explicitly starting and stopping the remove service.
* This demonstrates the implementation of a service that runs in a different
* process than the rest of the application, which is explicitly started and stopped
* as desired.</p>
*
* <p>Note that this is implemented as an inner class only keep the sample
* all together; typically this code would appear in some separate class.
*/
public static class Controller extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.remote_service_controller);
// Watch for button clicks.
Button button = (Button)findViewById(R.id.start);
button.setOnClickListener(mStartListener);
button = (Button)findViewById(R.id.stop);
button.setOnClickListener(mStopListener);
}
private OnClickListener mStartListener = new OnClickListener() {
public void onClick(View v) {
// Make sure the service is started. It will continue running
// until someone calls stopService().
// We use an action code here, instead of explictly supplying
// the component name, so that other packages can replace
// the service.
startService(new Intent(
"com.example.android.apis.app.REMOTE_SERVICE"));
}
};
private OnClickListener mStopListener = new OnClickListener() {
public void onClick(View v) {
// Cancel a previous call to startService(). Note that the
// service will not actually stop at this point if there are
// still bound clients.
stopService(new Intent(
"com.example.android.apis.app.REMOTE_SERVICE"));
}
};
}
// ----------------------------------------------------------------------
/**
* Example of binding and unbinding to the remote service.
* This demonstrates the implementation of a service which the client will
* bind to, interacting with it through an aidl interface.</p>
*
* <p>Note that this is implemented as an inner class only keep the sample
* all together; typically this code would appear in some separate class.
*/
public static class Binding extends Activity {
/** The primary interface we will be calling on the service. */
IRemoteService mService = null;
/** Another interface we use on the service. */
ISecondary mSecondaryService = null;
Button mKillButton;
TextView mCallbackText;
private boolean mIsBound;
/**
* Standard initialization of this activity. Set up the UI, then wait
* for the user to poke it before doing anything.
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.remote_service_binding);
// Watch for button clicks.
Button button = (Button)findViewById(R.id.bind);
button.setOnClickListener(mBindListener);
button = (Button)findViewById(R.id.unbind);
button.setOnClickListener(mUnbindListener);
mKillButton = (Button)findViewById(R.id.kill);
mKillButton.setOnClickListener(mKillListener);
mKillButton.setEnabled(false);
mCallbackText = (TextView)findViewById(R.id.callback);
mCallbackText.setText("Not attached.");
}
/**
* Class for interacting with the main interface of the service.
*/
private ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className,
IBinder service) {
// This is called when the connection with the service has been
// established, giving us the service object we can use to
// interact with the service. We are communicating with our
// service through an IDL interface, so get a client-side
// representation of that from the raw service object.
mService = IRemoteService.Stub.asInterface(service);
mKillButton.setEnabled(true);
mCallbackText.setText("Attached.");
// We want to monitor the service for as long as we are
// connected to it.
try {
mService.registerCallback(mCallback);
} catch (RemoteException e) {
// In this case the service has crashed before we could even
// do anything with it; we can count on soon being
// disconnected (and then reconnected if it can be restarted)
// so there is no need to do anything here.
}
// As part of the sample, tell the user what happened.
Toast.makeText(Binding.this, R.string.remote_service_connected,
Toast.LENGTH_SHORT).show();
}
public void onServiceDisconnected(ComponentName className) {
// This is called when the connection with the service has been
// unexpectedly disconnected -- that is, its process crashed.
mService = null;
mKillButton.setEnabled(false);
mCallbackText.setText("Disconnected.");
// As part of the sample, tell the user what happened.
Toast.makeText(Binding.this, R.string.remote_service_disconnected,
Toast.LENGTH_SHORT).show();
}
};
/**
* Class for interacting with the secondary interface of the service.
*/
private ServiceConnection mSecondaryConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className,
IBinder service) {
// Connecting to a secondary interface is the same as any
// other interface.
mSecondaryService = ISecondary.Stub.asInterface(service);
mKillButton.setEnabled(true);
}
public void onServiceDisconnected(ComponentName className) {
mSecondaryService = null;
mKillButton.setEnabled(false);
}
};
private OnClickListener mBindListener = new OnClickListener() {
public void onClick(View v) {
// Establish a couple connections with the service, binding
// by interface names. This allows other applications to be
// installed that replace the remote service by implementing
// the same interface.
bindService(new Intent(IRemoteService.class.getName()),
mConnection, Context.BIND_AUTO_CREATE);
bindService(new Intent(ISecondary.class.getName()),
mSecondaryConnection, Context.BIND_AUTO_CREATE);
mIsBound = true;
mCallbackText.setText("Binding.");
}
};
private OnClickListener mUnbindListener = new OnClickListener() {
public void onClick(View v) {
if (mIsBound) {
// If we have received the service, and hence registered with
// it, then now is the time to unregister.
if (mService != null) {
try {
mService.unregisterCallback(mCallback);
} catch (RemoteException e) {
// There is nothing special we need to do if the service
// has crashed.
}
}
// Detach our existing connection.
unbindService(mConnection);
unbindService(mSecondaryConnection);
mKillButton.setEnabled(false);
mIsBound = false;
mCallbackText.setText("Unbinding.");
}
}
};
private OnClickListener mKillListener = new OnClickListener() {
public void onClick(View v) {
// To kill the process hosting our service, we need to know its
// PID. Conveniently our service has a call that will return
// to us that information.
if (mSecondaryService != null) {
try {
int pid = mSecondaryService.getPid();
// Note that, though this API allows us to request to
// kill any process based on its PID, the kernel will
// still impose standard restrictions on which PIDs you
// are actually able to kill. Typically this means only
// the process running your application and any additional
// processes created by that app as shown here; packages
// sharing a common UID will also be able to kill each
// other's processes.
Process.killProcess(pid);
mCallbackText.setText("Killed service process.");
} catch (RemoteException ex) {
// Recover gracefully from the process hosting the
// server dying.
// Just for purposes of the sample, put up a notification.
Toast.makeText(Binding.this,
R.string.remote_call_failed,
Toast.LENGTH_SHORT).show();
}
}
}
};
// ----------------------------------------------------------------------
// Code showing how to deal with callbacks.
// ----------------------------------------------------------------------
/**
* This implementation is used to receive callbacks from the remote
* service.
*/
private IRemoteServiceCallback mCallback = new IRemoteServiceCallback.Stub() {
/**
* This is called by the remote service regularly to tell us about
* new values. Note that IPC calls are dispatched through a thread
* pool running in each process, so the code executing here will
* NOT be running in our main thread like most other things -- so,
* to update the UI, we need to use a Handler to hop over there.
*/
public void valueChanged(int value) {
mHandler.sendMessage(mHandler.obtainMessage(BUMP_MSG, value, 0));
}
};
private static final int BUMP_MSG = 1;
private Handler mHandler = new Handler() {
@Override public void handleMessage(Message msg) {
switch (msg.what) {
case BUMP_MSG:
mCallbackText.setText("Received from service: " + msg.arg1);
break;
default:
super.handleMessage(msg);
}
}
};
}
// ----------------------------------------------------------------------
/**
* Examples of behavior of different bind flags.</p>
*/
public static class BindingOptions extends Activity {
ServiceConnection mCurConnection;
TextView mCallbackText;
class MyServiceConnection implements ServiceConnection {
final boolean mUnbindOnDisconnect;
public MyServiceConnection() {
mUnbindOnDisconnect = false;
}
public MyServiceConnection(boolean unbindOnDisconnect) {
mUnbindOnDisconnect = unbindOnDisconnect;
}
public void onServiceConnected(ComponentName className,
IBinder service) {
if (mCurConnection != this) {
return;
}
mCallbackText.setText("Attached.");
Toast.makeText(BindingOptions.this, R.string.remote_service_connected,
Toast.LENGTH_SHORT).show();
}
public void onServiceDisconnected(ComponentName className) {
if (mCurConnection != this) {
return;
}
mCallbackText.setText("Disconnected.");
Toast.makeText(BindingOptions.this, R.string.remote_service_disconnected,
Toast.LENGTH_SHORT).show();
if (mUnbindOnDisconnect) {
unbindService(this);
mCurConnection = null;
Toast.makeText(BindingOptions.this, R.string.remote_service_unbind_disconn,
Toast.LENGTH_SHORT).show();
}
}
}
/**
* Standard initialization of this activity. Set up the UI, then wait
* for the user to poke it before doing anything.
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.remote_binding_options);
// Watch for button clicks.
Button button = (Button)findViewById(R.id.bind_normal);
button.setOnClickListener(mBindNormalListener);
button = (Button)findViewById(R.id.bind_not_foreground);
button.setOnClickListener(mBindNotForegroundListener);
button = (Button)findViewById(R.id.bind_above_client);
button.setOnClickListener(mBindAboveClientListener);
button = (Button)findViewById(R.id.bind_allow_oom);
button.setOnClickListener(mBindAllowOomListener);
button = (Button)findViewById(R.id.bind_waive_priority);
button.setOnClickListener(mBindWaivePriorityListener);
button = (Button)findViewById(R.id.bind_important);
button.setOnClickListener(mBindImportantListener);
button = (Button)findViewById(R.id.bind_with_activity);
button.setOnClickListener(mBindWithActivityListener);
button = (Button)findViewById(R.id.unbind);
button.setOnClickListener(mUnbindListener);
mCallbackText = (TextView)findViewById(R.id.callback);
mCallbackText.setText("Not attached.");
}
private OnClickListener mBindNormalListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindNotForegroundListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_NOT_FOREGROUND)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindAboveClientListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_ABOVE_CLIENT)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindAllowOomListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_ALLOW_OOM_MANAGEMENT)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindWaivePriorityListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection(true);
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_WAIVE_PRIORITY)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindImportantListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_IMPORTANT)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindWithActivityListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_ADJUST_WITH_ACTIVITY
| Context.BIND_WAIVE_PRIORITY)) {
mCurConnection = conn;
}
}
};
private OnClickListener mUnbindListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
}
};
}
}
1. 你应该始终捕获DeadObjectException异常，当连接被中断时这个异常被抛出。这是由远程方法抛出的唯一异常。
2. 对象的引用计数是跨进程的。
3. 通常绑定和解除绑定应该成对使用，而且要跟客户端的生命周期的启动和退出时刻匹配。例如：
如果你只需要在Activity可见的时候跟服务交互，那么就应该在onStart()期间绑定在onStop()期间解绑；
如果你想要Activity在终止的时候也能在后台接收响应事件，那么可以在onCreate()期间绑定，在onDestroy()期间解绑。这就意味着你的Activity需要在Activity的整个生命时都要使用这个服务，这样做要小心了，因为如果服务是在另一个进程中，那么你会增加这个进程的权重，是它变的更容易被系统杀死。
注意：通常在Activity的onResume()和onPause()期间不应该绑定和解除绑定服务，因为这些回调发生在每个生命周期的过渡期，并且应该保持在这些过渡期发生最低限度的处理。如果应用程序中多个Activity绑定了同一个服务，并且在这些Activity的其中两个之间有这样的过渡发生，那么这个服务就可以在当前Activity绑定解除（暂停期间）下一个Activity绑定之前（恢复期间）来销毁和创建。
绑定服务的示例代码：RemoteService.java
/** Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.android.apis.app;
import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.RemoteException;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Process;
import android.os.RemoteCallbackList;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
// Need the following import to get access to the app resources, since this
// class is in a sub-package.
import com.example.android.apis.R;
/**
* This is an example of implementing an application service that runs in a
* different process than the application. Because it can be in another
* process, we must use IPC to interact with it. The
* {@link Controller} and {@link Binding} classes
* show how to interact with the service.
*
* <p>Note that most applications <strong>do not</strong> need to deal with
* the complexity shown here. If your application simply has a service
* running in its own process, the {@link LocalService} sample shows a much
* simpler way to interact with it.
*/
public class RemoteService extends Service {
/**
* This is a list of callbacks that have been registered with the
* service. Note that this is package scoped (instead of private) so
* that it can be accessed more efficiently from inner classes.
*/
final RemoteCallbackList<IRemoteServiceCallback> mCallbacks
= new RemoteCallbackList<IRemoteServiceCallback>();
int mValue = 0;
NotificationManager mNM;
@Override
public void onCreate() {
mNM = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
// Display a notification about us starting.
showNotification();
// While this service is running, it will continually increment a
// number. Send the first message that is used to perform the
// increment.
mHandler.sendEmptyMessage(REPORT_MSG);
}
@Override
public void onDestroy() {
// Cancel the persistent notification.
mNM.cancel(R.string.remote_service_started);
// Tell the user we stopped.
Toast.makeText(this, R.string.remote_service_stopped, Toast.LENGTH_SHORT).show();
// Unregister all callbacks.
mCallbacks.kill();
// Remove the next pending message to increment the counter, stopping
// the increment loop.
mHandler.removeMessages(REPORT_MSG);
}
@Override
public IBinder onBind(Intent intent) {
// Select the interface to return. If your service only implements
// a single interface, you can just return it here without checking
// the Intent.
if (IRemoteService.class.getName().equals(intent.getAction())) {
return mBinder;
}
if (ISecondary.class.getName().equals(intent.getAction())) {
return mSecondaryBinder;
}
return null;
}
/**
* The IRemoteInterface is defined through IDL
*/
private final IRemoteService.Stub mBinder = new IRemoteService.Stub() {
public void registerCallback(IRemoteServiceCallback cb) {
if (cb != null) mCallbacks.register(cb);
}
public void unregisterCallback(IRemoteServiceCallback cb) {
if (cb != null) mCallbacks.unregister(cb);
}
};
/**
* A secondary interface to the service.
*/
private final ISecondary.Stub mSecondaryBinder = new ISecondary.Stub() {
public int getPid() {
return Process.myPid();
}
public void basicTypes(int anInt, long aLong, boolean aBoolean,
float aFloat, double aDouble, String aString) {
}
};
@Override
public void onTaskRemoved(Intent rootIntent) {
Toast.makeText(this, "Task removed: " + rootIntent, Toast.LENGTH_LONG).show();
}
private static final int REPORT_MSG = 1;
/**
* Our Handler used to execute operations on the main thread. This is used
* to schedule increments of our value.
*/
private final Handler mHandler = new Handler() {
@Override public void handleMessage(Message msg) {
switch (msg.what) {
// It is time to bump the value!
case REPORT_MSG: {
// Up it goes.
int value = ++mValue;
// Broadcast to all clients the new value.
final int N = mCallbacks.beginBroadcast();
for (int i=0; i<N; i++) {
try {
mCallbacks.getBroadcastItem(i).valueChanged(value);
} catch (RemoteException e) {
// The RemoteCallbackList will take care of removing
// the dead object for us.
}
}
mCallbacks.finishBroadcast();
// Repeat every 1 second.
sendMessageDelayed(obtainMessage(REPORT_MSG), 1*1000);
} break;
default:
super.handleMessage(msg);
}
}
};
/**
* Show a notification while this service is running.
*/
private void showNotification() {
// In this sample, we'll use the same text for the ticker and the expanded notification
CharSequence text = getText(R.string.remote_service_started);
// Set the icon, scrolling text and timestamp
Notification notification = new Notification(R.drawable.stat_sample, text,
System.currentTimeMillis());
// The PendingIntent to launch our activity if the user selects this notification
PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
new Intent(this, Controller.class), 0);
// Set the info for the views that show in the notification panel.
notification.setLatestEventInfo(this, getText(R.string.remote_service_label),
text, contentIntent);
// Send the notification.
// We use a string id because it is a unique number. We use it later to cancel.
mNM.notify(R.string.remote_service_started, notification);
}
// ----------------------------------------------------------------------
/**
* <p>Example of explicitly starting and stopping the remove service.
* This demonstrates the implementation of a service that runs in a different
* process than the rest of the application, which is explicitly started and stopped
* as desired.</p>
*
* <p>Note that this is implemented as an inner class only keep the sample
* all together; typically this code would appear in some separate class.
*/
public static class Controller extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.remote_service_controller);
// Watch for button clicks.
Button button = (Button)findViewById(R.id.start);
button.setOnClickListener(mStartListener);
button = (Button)findViewById(R.id.stop);
button.setOnClickListener(mStopListener);
}
private OnClickListener mStartListener = new OnClickListener() {
public void onClick(View v) {
// Make sure the service is started. It will continue running
// until someone calls stopService().
// We use an action code here, instead of explictly supplying
// the component name, so that other packages can replace
// the service.
startService(new Intent(
"com.example.android.apis.app.REMOTE_SERVICE"));
}
};
private OnClickListener mStopListener = new OnClickListener() {
public void onClick(View v) {
// Cancel a previous call to startService(). Note that the
// service will not actually stop at this point if there are
// still bound clients.
stopService(new Intent(
"com.example.android.apis.app.REMOTE_SERVICE"));
}
};
}
// ----------------------------------------------------------------------
/**
* Example of binding and unbinding to the remote service.
* This demonstrates the implementation of a service which the client will
* bind to, interacting with it through an aidl interface.</p>
*
* <p>Note that this is implemented as an inner class only keep the sample
* all together; typically this code would appear in some separate class.
*/
public static class Binding extends Activity {
/** The primary interface we will be calling on the service. */
IRemoteService mService = null;
/** Another interface we use on the service. */
ISecondary mSecondaryService = null;
Button mKillButton;
TextView mCallbackText;
private boolean mIsBound;
/**
* Standard initialization of this activity. Set up the UI, then wait
* for the user to poke it before doing anything.
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.remote_service_binding);
// Watch for button clicks.
Button button = (Button)findViewById(R.id.bind);
button.setOnClickListener(mBindListener);
button = (Button)findViewById(R.id.unbind);
button.setOnClickListener(mUnbindListener);
mKillButton = (Button)findViewById(R.id.kill);
mKillButton.setOnClickListener(mKillListener);
mKillButton.setEnabled(false);
mCallbackText = (TextView)findViewById(R.id.callback);
mCallbackText.setText("Not attached.");
}
/**
* Class for interacting with the main interface of the service.
*/
private ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className,
IBinder service) {
// This is called when the connection with the service has been
// established, giving us the service object we can use to
// interact with the service. We are communicating with our
// service through an IDL interface, so get a client-side
// representation of that from the raw service object.
mService = IRemoteService.Stub.asInterface(service);
mKillButton.setEnabled(true);
mCallbackText.setText("Attached.");
// We want to monitor the service for as long as we are
// connected to it.
try {
mService.registerCallback(mCallback);
} catch (RemoteException e) {
// In this case the service has crashed before we could even
// do anything with it; we can count on soon being
// disconnected (and then reconnected if it can be restarted)
// so there is no need to do anything here.
}
// As part of the sample, tell the user what happened.
Toast.makeText(Binding.this, R.string.remote_service_connected,
Toast.LENGTH_SHORT).show();
}
public void onServiceDisconnected(ComponentName className) {
// This is called when the connection with the service has been
// unexpectedly disconnected -- that is, its process crashed.
mService = null;
mKillButton.setEnabled(false);
mCallbackText.setText("Disconnected.");
// As part of the sample, tell the user what happened.
Toast.makeText(Binding.this, R.string.remote_service_disconnected,
Toast.LENGTH_SHORT).show();
}
};
/**
* Class for interacting with the secondary interface of the service.
*/
private ServiceConnection mSecondaryConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className,
IBinder service) {
// Connecting to a secondary interface is the same as any
// other interface.
mSecondaryService = ISecondary.Stub.asInterface(service);
mKillButton.setEnabled(true);
}
public void onServiceDisconnected(ComponentName className) {
mSecondaryService = null;
mKillButton.setEnabled(false);
}
};
private OnClickListener mBindListener = new OnClickListener() {
public void onClick(View v) {
// Establish a couple connections with the service, binding
// by interface names. This allows other applications to be
// installed that replace the remote service by implementing
// the same interface.
bindService(new Intent(IRemoteService.class.getName()),
mConnection, Context.BIND_AUTO_CREATE);
bindService(new Intent(ISecondary.class.getName()),
mSecondaryConnection, Context.BIND_AUTO_CREATE);
mIsBound = true;
mCallbackText.setText("Binding.");
}
};
private OnClickListener mUnbindListener = new OnClickListener() {
public void onClick(View v) {
if (mIsBound) {
// If we have received the service, and hence registered with
// it, then now is the time to unregister.
if (mService != null) {
try {
mService.unregisterCallback(mCallback);
} catch (RemoteException e) {
// There is nothing special we need to do if the service
// has crashed.
}
}
// Detach our existing connection.
unbindService(mConnection);
unbindService(mSecondaryConnection);
mKillButton.setEnabled(false);
mIsBound = false;
mCallbackText.setText("Unbinding.");
}
}
};
private OnClickListener mKillListener = new OnClickListener() {
public void onClick(View v) {
// To kill the process hosting our service, we need to know its
// PID. Conveniently our service has a call that will return
// to us that information.
if (mSecondaryService != null) {
try {
int pid = mSecondaryService.getPid();
// Note that, though this API allows us to request to
// kill any process based on its PID, the kernel will
// still impose standard restrictions on which PIDs you
// are actually able to kill. Typically this means only
// the process running your application and any additional
// processes created by that app as shown here; packages
// sharing a common UID will also be able to kill each
// other's processes.
Process.killProcess(pid);
mCallbackText.setText("Killed service process.");
} catch (RemoteException ex) {
// Recover gracefully from the process hosting the
// server dying.
// Just for purposes of the sample, put up a notification.
Toast.makeText(Binding.this,
R.string.remote_call_failed,
Toast.LENGTH_SHORT).show();
}
}
}
};
// ----------------------------------------------------------------------
// Code showing how to deal with callbacks.
// ----------------------------------------------------------------------
/**
* This implementation is used to receive callbacks from the remote
* service.
*/
private IRemoteServiceCallback mCallback = new IRemoteServiceCallback.Stub() {
/**
* This is called by the remote service regularly to tell us about
* new values. Note that IPC calls are dispatched through a thread
* pool running in each process, so the code executing here will
* NOT be running in our main thread like most other things -- so,
* to update the UI, we need to use a Handler to hop over there.
*/
public void valueChanged(int value) {
mHandler.sendMessage(mHandler.obtainMessage(BUMP_MSG, value, 0));
}
};
private static final int BUMP_MSG = 1;
private Handler mHandler = new Handler() {
@Override public void handleMessage(Message msg) {
switch (msg.what) {
case BUMP_MSG:
mCallbackText.setText("Received from service: " + msg.arg1);
break;
default:
super.handleMessage(msg);
}
}
};
}
// ----------------------------------------------------------------------
/**
* Examples of behavior of different bind flags.</p>
*/
public static class BindingOptions extends Activity {
ServiceConnection mCurConnection;
TextView mCallbackText;
class MyServiceConnection implements ServiceConnection {
final boolean mUnbindOnDisconnect;
public MyServiceConnection() {
mUnbindOnDisconnect = false;
}
public MyServiceConnection(boolean unbindOnDisconnect) {
mUnbindOnDisconnect = unbindOnDisconnect;
}
public void onServiceConnected(ComponentName className,
IBinder service) {
if (mCurConnection != this) {
return;
}
mCallbackText.setText("Attached.");
Toast.makeText(BindingOptions.this, R.string.remote_service_connected,
Toast.LENGTH_SHORT).show();
}
public void onServiceDisconnected(ComponentName className) {
if (mCurConnection != this) {
return;
}
mCallbackText.setText("Disconnected.");
Toast.makeText(BindingOptions.this, R.string.remote_service_disconnected,
Toast.LENGTH_SHORT).show();
if (mUnbindOnDisconnect) {
unbindService(this);
mCurConnection = null;
Toast.makeText(BindingOptions.this, R.string.remote_service_unbind_disconn,
Toast.LENGTH_SHORT).show();
}
}
}
/**
* Standard initialization of this activity. Set up the UI, then wait
* for the user to poke it before doing anything.
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.remote_binding_options);
// Watch for button clicks.
Button button = (Button)findViewById(R.id.bind_normal);
button.setOnClickListener(mBindNormalListener);
button = (Button)findViewById(R.id.bind_not_foreground);
button.setOnClickListener(mBindNotForegroundListener);
button = (Button)findViewById(R.id.bind_above_client);
button.setOnClickListener(mBindAboveClientListener);
button = (Button)findViewById(R.id.bind_allow_oom);
button.setOnClickListener(mBindAllowOomListener);
button = (Button)findViewById(R.id.bind_waive_priority);
button.setOnClickListener(mBindWaivePriorityListener);
button = (Button)findViewById(R.id.bind_important);
button.setOnClickListener(mBindImportantListener);
button = (Button)findViewById(R.id.bind_with_activity);
button.setOnClickListener(mBindWithActivityListener);
button = (Button)findViewById(R.id.unbind);
button.setOnClickListener(mUnbindListener);
mCallbackText = (TextView)findViewById(R.id.callback);
mCallbackText.setText("Not attached.");
}
private OnClickListener mBindNormalListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindNotForegroundListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_NOT_FOREGROUND)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindAboveClientListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_ABOVE_CLIENT)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindAllowOomListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_ALLOW_OOM_MANAGEMENT)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindWaivePriorityListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection(true);
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_WAIVE_PRIORITY)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindImportantListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_IMPORTANT)) {
mCurConnection = conn;
}
}
};
private OnClickListener mBindWithActivityListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
ServiceConnection conn = new MyServiceConnection();
if (bindService(new Intent(IRemoteService.class.getName()),
conn, Context.BIND_AUTO_CREATE | Context.BIND_ADJUST_WITH_ACTIVITY
| Context.BIND_WAIVE_PRIORITY)) {
mCurConnection = conn;
}
}
};
private OnClickListener mUnbindListener = new OnClickListener() {
public void onClick(View v) {
if (mCurConnection != null) {
unbindService(mCurConnection);
mCurConnection = null;
}
}
};
}
}
