How to respond to push notification view if app is

问题:

I have something fairly simple I want to do. I attach a custom piece of data to some push notifications that I handle in

-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

I look for the UIApplicationLaunchOptionsRemoteNotificationKey and hey presto there it is.

That method only gets called if my app is being launched for the first time. How do I read that same key if my application is running in the background already when the notification comes in and the user pressed the 'View' button on the notification? I want to send them to a particular view controller with that data open on it, the same as I do if the app is being launched for the first time from the notification.

回答1:

Check out application:didReceiveRemoteNotification:fetchCompletionHandler: in iOS 7 and later.

---

The method application:didReceiveRemoteNotification: is called if your app is running in the foreground. It also is called if your app is running in the background and the user engages with your push notification (thus making your app active).

So, the real question is how to determine if the app was in the foreground or if it was made active by the user engaging with your push notification.

It looks like this answer to the question didReceiveRemoteNotification when in background has the key:

You can tell whether your app was just brought to the foreground or not in application:didReceiveRemoteNotification: using this bit of code:

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo
{
    if ( application.applicationState == UIApplicationStateActive )
        // app was already in the foreground
    else
        // app was just brought from background to foreground
    ...
}

回答2:

To detect if the app was activated by remote notication, try this:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    NSDictionary *userInfo = [launchOptions objectForKey:UIApplicationLaunchOptionsRemoteNotificationKey];
    if (userInfo == NULL)
    {
        NSLog(@"didFinishLaunchingWithOptions user startup userinfo: %@", userInfo);
    }
    else
    {
        NSLog(@"didFinishLaunchingWithOptions notification startup userinfo: %@", userInfo);
    }
}