iOS:推送通知、UIApplicationStateInactive 和快速应用切换

Question

根据 Apple 文档，为了查明用户是否点击了您的推送通知，您应该检查 application:didReceiveRemoteNotification 中的 applicationState :

If the value is UIApplicationStateInactive, the user tapped the action button; if the value is UIApplicationStateActive, the application was frontmost when it received the notification.

我发现这并不总是正确的。例如:

双击主页按钮以显示系统托盘并进入“快速应用程序切换模式”，您的应用程序向上滑动以显示其他正在运行的应用程序，并且您的应用程序将进入非事件状态(即使它仍然大部分可见)。如果您在此模式下收到推送通知，您的应用委托(delegate)将仍收到application:didReceiveRemoteNotification:，此时您的applicationState 为UIApplicationStateActive。根据文档，您应该像用户点击警报一样对待它……但在这种情况下他们没有。不仅如此，用户甚至没有看到推送通知(可能是因为在这种模式下您的应用程序的顶部被截断了)。

有谁知道检测处于“快速应用切换模式”或正确处理通知的方法吗？

Answer 1

我能够通过一些漂亮的检查自己修复它...

从本质上讲，这整个事情的关键是

-(void)applicationDidEnterBackground:(UIApplication *)application;

当您进入快速应用切换(或控制中心)时不会调用此方法，因此您需要根据它设置检查。

@property                     BOOL isInBackground;
@property (nonatomic, retain) NSMutableArray *queuedNotifications;

当您收到通知时...

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo {
 UIApplicationState appState = application.applicationState;
 // Check if we're in this special state. If so, queue the message up
 if (appState == UIApplicationStateInactive && !self.isInBackground) {
    // This is a special case in which we're in fast app switching or control center
    if (!self.queuedNotifications) {
        self.queuedNotifications = [NSMutableArray array];
    }

    // Queue this to show when we come back
    [self.queuedNotifications addObject:userInfo];
 }
}

然后当我们回来的时候...

- (void)applicationDidBecomeActive:(UIApplication *)application {
     application.applicationIconBadgeNumber = 0;


 if (!self.isInBackground) {
    // Show your notifications here

    // Then make sure to reset your array of queued notifications
    self.queuedNotifications = [NSMutableArray array];
 }
}

您可能还想做的另一件事是检查这种特殊情况，即快速切换应用程序和用户转到其他地方。我在设置 isInBackground BOOL 之前执行此操作。我选择将它们作为本地通知发送

-(void)applicationDidEnterBackground:(UIApplication *)application {

  for (NSDictionary *eachNotification in self.queuedNotifications) {
     UILocalNotification *notification = [self convertUserInfoToLocalNotification:eachNotification];
     [[UIApplication sharedApplication] scheduleLocalNotification:notification];
 }
 self.queuedNotifications = [NSMutableArray array];
 self.isInBackground = YES;
}