小编Oly*_*tre的帖子

我有一个具有一些表单字段的应用程序。提交表单后，它将数据写入我的核心数据对象。但是，当再次提交表单时，它会覆盖现有数据而不是附加到它，这正是我想要发生的情况。

    guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {
        return
    }

    let managedContext = appDelegate.persistentContainer.viewContext
    let userEntity = NSEntityDescription.entity(forEntityName: "User", in: managedContext)

    let newUser = NSManagedObject(entity: userEntity! , insertInto: managedContext)
    newUser.setValue(titleField, forKey: "title")
    newUser.setValue(firstNameField, forKey: "firstName")
    newUser.setValue(lastNameField, forKey: "lastName")
    newUser.setValue(emailField, forKey: "email")
    newUser.setValue(affiliatedOrgField, forKey: "affiliatedOrg")
    newUser.setValue(ukRegionField, forKey: "ukRegion")
    newUser.setValue(privacyChecked, forKey: "privacyPolicy")

    do {
        try managedContext.save()
    } catch let error as NSError {
        print("Could not save. \(error), \(error.userInfo)")
    }

我尝试过使用

let userEntity = NSEntityDescription.insertNewObject(forEntityName: "User", into: managedContext)
let newUser = …

在撰写这篇文章之前,我对UserNotification Framework进行了大量研究,取代了IOS 10中的UILocalNotification.我也按照本教程学习了有关这一新功能的所有内容:http://useyourloaf.com/blog/local-notifications-with- ios-10 /.

今天我遇到了很多麻烦来实现这些琐碎的通知,因为它是最近的新功能,我找不到任何解决方案(特别是在目标C中)!我目前有2个不同的通知,一个警报和一个徽章更新.

警报问题

在将我的手机从IOS 10.1升级到10.2之前,我在Appdelegate上发出警报,当用户手动关闭应用程序时,该警报立即被触发:

-(void)applicationWillTerminate:(UIApplication *)application {
        NSLog(@"applicationWillTerminate");

        // Notification terminate
        [self registerTerminateNotification];
}

// Notification Background terminate 
-(void) registerTerminateNotification {
    // the center
    UNUserNotificationCenter * notifCenter = [UNUserNotificationCenter currentNotificationCenter];

    // Content
    UNMutableNotificationContent *content = [UNMutableNotificationContent new];
    content.title = @"Stop";
    content.body = @"Application closed";
    content.sound = [UNNotificationSound defaultSound];
    // Trigger 
    UNTimeIntervalNotificationTrigger *trigger = [UNTimeIntervalNotificationTrigger triggerWithTimeInterval:1 repeats:NO];
    // Identifier
    NSString *identifier = @"LocalNotificationTerminate";
    // création de la requête …

在我的应用程序中，我想滑入和滑出视图控制器。因此，为此我正在使用自定义过渡，但应用程序崩溃了。我无法找出确切的问题所在。请帮帮我。

代码

class CustomTransition: NSObject, UIViewControllerAnimatedTransitioning,UIViewControllerTransitioningDelegate {

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {

        // get reference to our fromView, toView and the container view that we should perform the transition in
        let container = transitionContext.containerView
        let fromView = transitionContext.view(forKey: UITransitionContextViewKey.from)! // the app crashes here saying nil founded
        let toView = transitionContext.view(forKey: UITransitionContextViewKey.to)!
        let animationDuration = self .transitionDuration(using: transitionContext)
        let offScreenRight = CGAffineTransform(translationX: container.frame.width, y: 0)
        let offScreenLeft = CGAffineTransform(translationX: -container.frame.width, y: 0)

        toView.transform = offScreenRight

        // add the both views …

我正在尝试创建具有样式UIAlertControllerStyleActionSheet（以前称为UIActionSheet）的自定义UIAlertController，并且遇到了很多麻烦，无法简单地对其进行自定义。我希望UIAlertAction 在左侧包含一个图像并减小按钮的大小。