[英]How to get the value of the variable that is assigned in a closure (Swift)
[英]How can a variable be assigned to a UIInteraction in Swift?
为什么我需要变量? 因为在单元格中进行 2 次不同的长按时,需要在func contextMenuInteraction
中调用 2 个图像
下面是我的代码,我在其中为每个长按交互分配了一个变量。 我收到错误Thread 1: Swift runtime failure: Unexpectedly found nil while implicitly unwrapping an Optional value
//在scope
var dd : UIInteraction!
var cc : UIInteraction!
@IBOutlet weak var immy: UIImageView!
//在 override func awakeFromNib() 和一个 objC 分别长按 function
immy.addInteraction(dd) // (this is in the override nib)
self.like.addInteraction(self.cc) //(this is in the @objc func didLongPress())
下面是调用 2 个交互的func ContextMenuInteraction
func contextMenuInteraction(_ interaction: UIContextMenuInteraction, configurationForMenuAtLocation location: CGPoint) -> UIContextMenuConfiguration? {
UIContextMenuConfiguration(identifier: nil, previewProvider: {
if self.dd as! NSObject == interaction {
if let unwrappedImage = self.immy.image {
return ImagePreviewController(image:unwrappedImage)
}
else {
return nil
}
// put dd stuff here
} else if self.cc as! NSObject == interaction {
// put cc stuff here
let image3 = UIImage(named:"ring-309550-2.png")
if let unwrappedImage1 = image3 {
return ImagePreviewController(image:unwrappedImage1)
}
else {
return nil
}
}
else {
return nil
}
})
}
意外发现 nil 错误发生在哪里 - 在这一行中:
immy.addInteraction(dd)
更新这个问题已经解决了(不是我——reddit 上的某个人)
// scope
var dd: UIContextMenuInteraction
var cc: UIContextMenuInteraction
// inside init()
self.dd = UIContextMenuInteraction(delegate: self)
self.cc = UIContextMenuInteraction(delegate: self)
// downstream
image1.addInteraction(dd)
image2.addinteraction(cc)
// inside contextMenuInteraction()
if self.dd == interaction {
...
} else if self.cc == interaction {
...
}
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