iOS開發之打開系統設置通知權限頁面

- (void)viewDidAppear:(BOOL)animated 
{
　　//首先判斷應用通知是否授權，注意iOS10.0之后方法不一樣
    if (@available(iOS 10.0, *)) {
        [[UNUserNotificationCenter currentNotificationCenter] getNotificationSettingsWithCompletionHandler:^(UNNotificationSettings * _Nonnull settings) {
            if (settings.authorizationStatus == UNAuthorizationStatusNotDetermined)
            {
                NSLog(@"未選擇");
                [self opentNotificationAlert];
            }else if (settings.authorizationStatus == UNAuthorizationStatusDenied){
                NSLog(@"未授權");
                [self opentNotificationAlert];
            }else if (settings.authorizationStatus == UNAuthorizationStatusAuthorized){
                NSLog(@"已授權");
            }
        }];
    } else {
        if ([[UIApplication sharedApplication] currentUserNotificationSettings].types == 0) {
            [self opentNotificationAlert];
        }
    }
}

/** 跳轉系統設置方法*/
- (void)opentNotificationAlert 
{
    /**< 彈出框 */
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"推送通知關閉"
                                                                             message:@"請前往打開通知，獲取更多精彩瞬間！"
                                                                      preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

    }]];
    [alertController addAction:[UIAlertAction actionWithTitle:@"確定" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        [self.presentedViewController dismissViewControllerAnimated:YES completion:nil];
        if (@available(iOS 10.0, *)) {
            [[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString] options:@{} completionHandler:nil];
        } else {
            [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=NOTIFICATIONS_ID&path=com.xxx.xxx"]];//prefs:root=服務&path=項目bundleID
　　　　　} 

　　}]; 
　　[self presentViewController:alertController animated:YES completion:nil]; 
}