是否可以使用UILocalNotification喚醒後臺任務

Question

我想知道，如果有可能以某種方式「喚醒」後臺任務，以便快速檢查網絡中的某個任務。我認爲這可以通過UILocalNotification完成，但是，無論我嘗試了什麼，我都無法在應用程序處於後臺時使didReceiveLocalNotification執行任何操作。啓動後，我立即通過按Home按鈕關閉應用程序（本地通知發生延遲10秒鐘）。此代碼工作完全當應用程序在前臺，而只是一種坐在那裏......

在應用程序委託頭文件：

UILocalNotification *localNotif; 

爲了測試，我設置了本地通知在快速射擊appDelegate啓動。

localNotif = [[UILocalNotification alloc] init]; 
localNotif.fireDate = [NSDate dateWithTimeIntervalSinceNow:10]; // the date you want the notification to fire. 
localNotif.timeZone = [NSTimeZone defaultTimeZone]; 
[[UIApplication sharedApplication] scheduleLocalNotification:localNotif]; 

NSLog(@"setup the timer for 10 seconds"); 





- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification { 
UIApplicationState state = [application applicationState]; 
NSLog(@"getting kicked"); 
if (state == UIApplicationStateInactive) { 

    // Application was in the background when notification was delivered. 

    NSLog(@"INACTIVE.."); 
} else { 
    NSLog(@"ACTIVE.."); 

} 

}

Answer 1

用戶有兩個選擇：＃1）他們希望看到你的應用程序的通知。 ＃2）如果爲您的應用啓用了通知，他們是否想要點擊通知來啓動您的應用。如果他們確實接受通知並在應用程序處於後臺時打開通知，則會調用application:didReceiveLocalNotification。爲了清楚起見，用戶必須接受通知（例如滑動通知下方的滑塊），否則將調用NOTHING。

- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification { 
    NSLog(@"%@", notification); 
} 

如果您的應用程序已終止application:didFinishLaunchingWithOptions:被稱爲 -

- (BOOL)application:(UIApplication *) 
application didFinishLaunchingWithOptions: 
(NSDictionary *)launchOptions { 
    UILocalNotification *theNotification = 
     [launchOptions 
     objectForKey:UIApplicationLaunchOptionsLocalNotificationKey]; 
    NSLog(@"%@", theNotification); 

    return YES; 
}