我使用gcm在发布图像时获得通知，然后下载并处理它：
public class GcmBroadcastReceiver extends WakefulBroadcastReceiver
{
@Override
public void onReceive(Context context, Intent intent)
{
DataUtils.log("In GcmBroadcastReceiver! threadname is " + Thread.currentThread().getName());
// Explicitly specify that GcmIntentService will handle the intent.
ComponentName comp = new ComponentName(context.getPackageName(), GcmIntentService.class.getName());
// Start the service, keeping the device awake while it is launching.
startWakefulService(context, (intent.setComponent(comp)));
setResultCode(Activity.RESULT_OK);
}
}
这是我的gcminentservice的开始：
public class GcmIntentService extends IntentService
{
public static final int NOTIFICATION_ID = 1;
public GcmIntentService()
{
super("GcmIntentService");
}
@Override
protected void onHandleIntent(Intent intent)
{
DataUtils.log("In GcmIntentService onHandleIntent(), threadname is " + Thread.currentThread().getName());
Bundle extras = intent.getExtras();
GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
// The getMessageType() intent parameter must be the intent you received in your BroadcastReceiver.
String messageType = gcm.getMessageType(intent);
if (!extras.isEmpty()) // has effect of unparcelling Bundle
{
/*
* Filter messages based on message type. Since it is likely that GCM will be
* extended in the future with new message types, just ignore any message types you're
* not interested in, or that you don't recognize.
*/
if (GoogleCloudMessaging.MESSAGE_TYPE_SEND_ERROR.equals(messageType))
{
DataUtils.log("In GcmIntentService - Send error: " + extras.toString());
} else if (GoogleCloudMessaging.MESSAGE_TYPE_DELETED.equals(messageType))
{
DataUtils.log("In GcmIntentService - Deleted messages on server: " + extras.toString());
// If it's a regular GCM message, do some work.
} else if (GoogleCloudMessaging.MESSAGE_TYPE_MESSAGE.equals(messageType))
{
String notificationType = extras.getString(MyAppApi.GCM_MSG_TYPE_KEY);
if(DataUtils.isEmpty(notificationType)) {
DataUtils.log("In GcmIntentService - notificationType is empty!");
} else if(notificationType.equalsIgnoreCase(MyAppApi.GCM_IS_NEW_WALLPAPER)) {
//We're about to receive a new image!
DataUtils.log("In GcmIntentService - Receiving a new image!");
processNewWallpaper();
} else if(notificationType.equalsIgnoreCase(MyAppApi.GCM_IS_FRIEND_NOTIFICATION)) {
//We're about to receive a friend notification
DataUtils.log("In GcmIntentService - Receiving a friend notification!");
processFriendNotification();
} else {
//Unknown
DataUtils.log("In GcmIntentService - Receiving unknown message type! " + notificationType);
}
} else {
DataUtils.log("In GcmIntentService - Unknown GCM message: " + extras.toString());
}
}
//Release the wake lock provided by the WakefulBroadcastReceiver.
GcmBroadcastReceiver.completeWakefulIntent(intent);
}
}
服务似乎会随机死亡。从日志中：
01-13 20:00:44.436: I/ActivityManager(375): Process com.grakk.android (pid 23227) has died.
01-13 20:00:44.444: W/ActivityManager(375): Scheduling restart of crashed service com.grakk.android/.GcmIntentService in 11426ms
当代码收到gcm消息时，它所做的是下载一个图像，然后向用户显示一个通知（这类似于普通的聊天应用程序）。
一位测试人员告诉我，一旦他收到一个图像，但没有收到通知，这意味着服务本身已经启动，并完成了部分工作，但没有完成。
通知代码与图像的下载和处理一起在processNewWallpaper（）中运行。代码如下：
...
if(senderContact == null) {
sendNotification(null, message, true);
} else {
sendNotification(senderContact.getName(), message.trim(), false);
}
...
通知方法：
...
// Put the message into a notification and post it. This is just one simple example
// of what you might choose to do with a GCM message.
@SuppressWarnings("deprecation")
@TargetApi(16)
private void sendNotification(String name, String message, boolean isAnonymous)
{
Context context = GcmIntentService.this;
NotificationManager mNotificationManager = (NotificationManager)this.getSystemService(Context.NOTIFICATION_SERVICE);
PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, ContactsActivity.class), 0);
Notification.Builder mBuilder = new Notification.Builder(this)
.setSmallIcon(R.drawable.ic_launcher)
.setContentTitle(context.getString(R.string.app_name));
String textToShow = null;
if(DataUtils.isEmpty(message))
{
if(isAnonymous) {
textToShow = context.getString(R.string.notification_text_anonymous);
} else {
textToShow = String.format(getResources().getString(R.string.notification_text_friend), name);
}
} else {
textToShow = message;
}
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
mBuilder.setStyle(new Notification.BigTextStyle().bigText(textToShow));
}
mBuilder.setContentText(textToShow);
mBuilder.setAutoCancel(true);
Uri alarmSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
mBuilder.setSound(alarmSound);
mBuilder.setContentIntent(contentIntent);
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
} else {
mNotificationManager.notify(NOTIFICATION_ID, mBuilder.getNotification());
}
}
我可以通过给自己发送一张图片，然后反复按android的back按钮，直到我不在应用程序中，来重现这一点。我可以跟踪显示图像已下载的日志消息，但是在显示通知之前图像会消失。
这种情况并不总是发生。有时显示通知，有时不显示。
我不知道可能的原因是什么，也不知道如何调试。有什么小窍门吗？
最佳答案
你打过OnCreate()班的GcmIntentService吗？
下面是一些示例代码：
public class GcmIntentService extends IntentService {
String mes;
private Handler mHandler;
public GcmIntentService() {
super("GcmIntentService");
}
@Override
public void onCreate() {
super.onCreate();
mHandler = new Handler();
}
@Override
protected void onHandleIntent(Intent intent) {
Bundle extras = intent.getExtras();
GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
String messageType = gcm.getMessageType(intent);
mes = extras.getString("title");
showToast();
Log.i("GCM", "Recevied: (" + messageType + ") " + extras.getString("title"));
GcmReceiver.completeWakefulIntent(intent);
}
public void showToast() {
mHandler.post(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(), mes, Toast.LENGTH_LONG).show();
}
});
}
}
编辑：为
GCMhere添加有用的youtube教程。