在iOS 8中要求获得本地通知的权限,但仍然拥有iOS 7应用程序支持

Question

我有一个使用本地通知的应用程序.在iOS 7中,一切正常,但在iOS 8中,应用程序需要请求用户显示通知的权限.要在iOS 8中请求权限我正在使用:

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

{
  [application registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeBadge|UIUserNotificationTypeSound categories:nil]];
}

它在Xcode 6和iOS 8中工作正常.当我在Xcode 5中打开相同的项目时,错误是语义问题."使用未声明的标识符'UIUserNotificationSettings'."

如何让应用程序与iOS 7和8一起使用,并使这两个版本的通知正常工作.

Answer 1

以下答案做了一些假设:

1. 使用Xcode 6时,应用必须使用iOS 8的Base SDK正确构建,并且在使用Xcode 5时必须使用iOS 7的Base SDK正确构建.
2. 无论Base SDK和Xcode版本如何,该应用程序都必须支持iOS 7(或更早版本)的部署目标.

码:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // None of the code should even be compiled unless the Base SDK is iOS 8.0 or later
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 80000
    // The following line must only run under iOS 8. This runtime check prevents
    // it from running if it doesn't exist (such as running under iOS 7 or earlier).
    if ([application respondsToSelector:@selector(registerUserNotificationSettings:)]) {
        [application registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeBadge|UIUserNotificationTypeSound categories:nil]];
    }
#endif
}

所有这些都包含在Apple SDK兼容性指南中.

Answer 2

我简单地实施了 -

if([UIApplication instancesRespondToSelector:@selector(registerUserNotificationSettings:)]) {

    [[UIApplication sharedApplication] registerForRemoteNotifications];
    UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:(UIUserNotificationTypeBadge | UIUserNotificationTypeSound | UIUserNotificationTypeAlert) categories:nil];
    [[UIApplication sharedApplication] registerUserNotificationSettings:settings];

} else {
    [[UIApplication sharedApplication] registerForRemoteNotificationTypes:UIRemoteNotificationTypeSound | UIRemoteNotificationTypeAlert | UIRemoteNotificationTypeBadge];
}