GCM push notification when iOS app is in the backg

问题:

I'm trying to send push notifications to my iOS app with GCM. The app doesn't get the notification when it's in the background but it does when it's in the foreground. I was testing the push notifications with a PHP script also which sends the message directly to the APNS and it's working in the background.

The JSON sent to GCM: (I'm sending it from a rest client for testing)

{
  "to" : "token...",
  "notification" : {
    "title": "GCM TITLE",
    "body" : "FROM GCM",
    "badge": "1",
    "sound": "default"
  }
}

Not working: The userInfo received from GCM in didReceiveRemoteNotification:

Notification received: [aps: {
    alert =     {
        body = "FROM GCM";
        title = "GCM TILE";
    };
    badge = 1;
    sound = default;
}, gcm.message_id: 123...]

Working: The userInfo received when sent from the PHP script (I also added the message_id to the JSON to see if that's the problem)

Notification received: [aps: {
    alert =     {
        body = "FROM PHP";
        title = "PHP TITLE";
    };
    badge = 2;
    sound = default;
}, gcm.message_id: 123...]

I tried adding content_available to the JSON with different combinations but didn't help, the Content-Type and Authorization request headers are also set:

Content-Type:application/json
Authorization:key=... 

回答1:

In case if someone has the same problem, the solution was for me to add the "priority": "high" to the JSON. This way I get the notifications in the background.

{
  "to" : "token...",
  "priority": "high",
  "notification" : {
    "title": "GCM TITLE",
    "body" : "FROM GCM",
    "badge": "1",
    "sound": "default"
  }
}

回答2:

To get notification when app is in background i note that we need to add:

"content_available":true // when app in background
"priority":"high" //when app is completely closed not even running in background

 // "content_available":true  ..most important field 

{
"to" : "token...",
 "priority":"high",
 "content_available":true,
 "notification" : {
 "title": "GCM TITLE",
 "body" : "FROM GCM",
 "badge": "1",
 "sound": "default"
  }
}