Question

我有问题。我尝试使用UIImageView函数从appDelegate更改NSNotificationCenter，但收到错误消息。当我使用didFinishLaunchingWithOptions从NSNotificationCenter函数更改此内容后，我得到Exc_Breakpoint

在AppDelegate中：

  var classView: ViewController!

 func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: NSDictionary?) -> Bool {
       NSNotificationCenter.defaultCenter().addObserver(self, selector: "myFunction:" ....
 }

 func myFunction(note: NSNotofication){
      classView.myImageView.image = UIImage(named: "picture1") //Here get the crash
  }

如何正确调用并更改UIImageView的{{1}}？

提前致谢！

Answer 1

从视图控制器发布通知并在userInfo通知中传递imageView，并在app delegate中提取imageView并将图像设置为此类，

class ViewController: UIViewController{

  override func viewDidLoad() {
    let imageView = UIImageView(frame: view.bounds)
    self.view.addSubview(imageView)

    // post notification and pass imageview in userInfo

    NSNotificationCenter.defaultCenter().postNotificationName("MySetImageViewNotification", object: nil, userInfo: ["imageView": imageView])
  }
}

在app delegate中，你会观察到通知，提取imageview并将图像设置为这样，

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

  func application(application: UIApplication!, didFinishLaunchingWithOptions launchOptions: NSDictionary!) -> Bool {
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "setImageViewNotification:", name: "MySetImageViewNotification", object: nil)
    return true
  }

  func setImageViewNotification(note: NSNotification){
    let userInfo = note.userInfo as [String: UIImageView]
    let imageView = userInfo["imageView"]
    imageView?.image = UIImage(named: "image.png")
  }
}

如何从Swift中的appdelegate更改UIImageVIew？

1 个答案: