推送通知有效負載未保存在某些設備上

Question

我在處理某些設備上的通知有效負載時出現問題。我通過Parse Cloud功能向我的用戶發送推送通知。

我使用下面的方法捕獲通知並存儲其有效負載，以便用戶可以在專用視圖中查看所有收到的通知。在我的個人設備上，我通常會收到通知，並且它會正確保存在朋友的設備上，但通知是否到達，但是如果應用程序在後臺，則不會保存有效內容，而如果應用程序處於前景，則會保存有效內容。

這可能是設備本身的問題嗎？或者也許是與手機供應商有關的東西（我有h3g，他有沃達豐）？

-(void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler{ 
// Parse push handler will show a UIAlertView 
[PFPush handlePush:userInfo]; 

if (application.applicationState == UIApplicationStateInactive) { 

    // tha app is inactive, transitioning to or from the background   
    completionHandler(UIBackgroundFetchResultNoData); 

} else if (application.applicationState == UIApplicationStateBackground) { 

    // tha app is running in background 
    // add the notification to the notificationsArrayRecord 
    NSDate *now = [[NSDate alloc]init]; 
    NSDictionary *aps = userInfo[@"aps"]; 
    NSString *alertMessage = aps[@"alert"]; 
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; 

    NSMutableArray *notificationsArrayRecord = [[defaults arrayForKey:@"notificationsArrayRecord"] mutableCopy]; 
    [notificationsArrayRecord addObject:@[now,alertMessage]]; 
    [defaults setValue: notificationsArrayRecord forKey:@"notificationsArrayRecord"]; 

    // update the notifications counter 
    NSInteger pushCount = [[NSUserDefaults standardUserDefaults] integerForKey: @"pushCount"]; 
    pushCount ++; 
    [defaults setInteger: pushCount forKey:@"pushCount"]; 
    [defaults synchronize]; 

    completionHandler(UIBackgroundFetchResultNewData); 
} else {   
    // the app is running in foreground 

    // add the notification to the notificationsArrayRecord 
    NSDate *now = [[NSDate alloc]init]; 
    NSDictionary *aps = userInfo[@"aps"]; 
    NSString *alertMessage = aps[@"alert"]; 
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; 

    NSMutableArray *notificationsArrayRecord = [[defaults arrayForKey:@"notificationsArrayRecord"] mutableCopy]; 
    [notificationsArrayRecord addObject:@[now,alertMessage]]; 
    [defaults setValue: notificationsArrayRecord forKey:@"notificationsArrayRecord"]; 

    // update the notifications counter 
    NSInteger pushCount = [[NSUserDefaults standardUserDefaults] integerForKey: @"pushCount"]; 
    pushCount ++; 
    [defaults setInteger: pushCount forKey:@"pushCount"]; 
    [defaults synchronize]; 

    completionHandler(UIBackgroundFetchResultNewData); 

    // refresh the menu buttons and the notification counter 
    [[NSNotificationCenter defaultCenter] postNotificationName:@"appDidReceiveNotificationWhileActive" object:nil]; 
    } 
    } 

Answer 1

我想這個問題是你如何處理應用程序的狀態UIApplicationStateInactive。在這種情況下，您不存儲信息。您應該在這種情況下存儲它，因爲當您收到通知時，應用程序顯然可能處於此狀態。這也解釋了爲什麼它有時會失敗。 另請參閱this question，其中指出當設備收到通知時，該應用有時處於狀態UIApplicationStateInactive。

你應該重構你的代碼將數據存儲在所有情況下：

-(void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler{ 
    // Parse push handler will show a UIAlertView 
    [PFPush handlePush:userInfo]; 

    // add the notification to the notificationsArrayRecord  
    NSDate *now = [[NSDate alloc]init]; 
    NSDictionary *aps = userInfo[@"aps"]; 
    NSString *alertMessage = aps[@"alert"]; 
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; 

    NSMutableArray *notificationsArrayRecord = [[defaults arrayForKey:@"notificationsArrayRecord"] mutableCopy]; 
    [notificationsArrayRecord addObject:@[now,alertMessage]]; 
    [defaults setValue: notificationsArrayRecord forKey:@"notificationsArrayRecord"]; 

    // update the notifications counter 
    NSInteger pushCount = [[NSUserDefaults standardUserDefaults] integerForKey: @"pushCount"]; 
    pushCount ++; 
    [defaults setInteger: pushCount forKey:@"pushCount"]; 
    [defaults synchronize]; 

    if (application.applicationState == UIApplicationStateInactive) { 
     // the app is inactive, transitioning to or from the background   
     completionHandler(UIBackgroundFetchResultNoData); 
    } else if (application.applicationState == UIApplicationStateBackground) { 
     // the app is running in background 
     completionHandler(UIBackgroundFetchResultNewData); 
    } else {   
     // the app is running in foreground 
     completionHandler(UIBackgroundFetchResultNewData); 

     // refresh the menu buttons and the notification counter 
     [[NSNotificationCenter defaultCenter] postNotificationName:@"appDidReceiveNotificationWhileActive" object:nil]; 
    } 
} 

更新： 我不知道有關調用completionHandler(UIBackgroundFetchResultNoData)在applicationState（不知道這是好的），但也許您需要撥打completionHandler(UIBackgroundFetchResultNewData)來代替，在這種情況下，也需要存儲數據。

此外，請確保您已正確配置所有內容，以便在後臺接收通知，[請參閱此處]回答（https://stackoverflow.com/a/31450953/594074）。