iOS中的权限在官方概念中叫能力（capabilities）。它是app要拥有某些功能。目前在iOS11SDK中一共有22种。我们下面按照最为常用开始罗列，争取坚持写完。

1. Push Notifications
   64C70E4CF32BF6F610B2BACFDBBFDAD6.jpg
   
   

   1.1 申请。首先在XCode中capabilities中找到Push Notification（如上图的部分）打开后面的开关。证书配置不提，代码申请，触发系统弹框。极光推送已经封装了申请部分，如果使用了极光推送不用手动申请。

    if ([UIDevice currentDevice].systemVersion.doubleValue < 8.0) {
        [application registerForRemoteNotificationTypes:UIRemoteNotificationTypeBadge|UIRemoteNotificationTypeSound|UIRemoteNotificationTypeAlert];
    }else if([UIDevice currentDevice].systemVersion.doubleValue < 10.0){
        UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeBadge| UIUserNotificationTypeSound|UIUserNotificationTypeAlert  categories:nil];
        [application registerUserNotificationSettings:settings];
        [application registerForRemoteNotifications];
    }else{
        if (@available(iOS 10.0, *)) {
            UNAuthorizationOptions options = UNAuthorizationOptionBadge|UNAuthorizationOptionSound|UNAuthorizationOptionAlert|UNAuthorizationOptionCarPlay;
            [[UNUserNotificationCenter currentNotificationCenter]requestAuthorizationWithOptions:options completionHandler:^(BOOL granted, NSError * _Nullable error) {
                
            }];
        }
        [application registerForRemoteNotifications];
    }
   

   判断当前状态

    if (@available(iOS 10.0, *)) {//iOS 10 以后
        [[UNUserNotificationCenter currentNotificationCenter]getNotificationSettingsWithCompletionHandler:^(UNNotificationSettings * _Nonnull settings) {
            UNNotificationSetting notificationSetting = settings.notificationCenterSetting;
            if (notificationSetting == UNNotificationSettingEnabled) {
                
            }else if(notificationSetting == UNNotificationSettingDisabled){
                
            }else{//UNNotificationSettingNotSupported
                
            }
        }];
    } else {
        if (@available(iOS 8.0, *)) {
            if([[UIApplication sharedApplication] currentUserNotificationSettings].types == UIUserNotificationTypeNone){
                
            }else{
                
            }
        }else{
            if ([[UIApplication sharedApplication] enabledRemoteNotificationTypes]  == UIRemoteNotificationTypeNone){
                
            }else{
                
            }
        }
    }
   

   跳转设置

    if ([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]]){
        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];
    }