我是 swift 的新手。我已经制作了通用操作表
import Foundation
extension UIAlertController{
func action(mes:String,tit:String,tit2:String,operation1:(),operation2:()) {
let actionSheet = UIAlertController(title: "", message:mes, preferredStyle: .actionSheet)
let EButton = UIAlertAction(title:tit ,
style: .default,
handler: { _ in
operation1
})
let AllEButton = UIAlertAction(title:tit2,
style: .default ,
handler:{ _ in
operation2
})
let cancelAction = UIAlertAction(title: "Cancel",
style: .cancel,
handler: nil)
[EButton, AllEButton, cancelAction].forEach { $0.setValue(UIColor.red, forKey: "titleTextColor")
}
actionSheet.addAction(EButton)
actionSheet.addAction(AllEButton)
actionSheet.addAction(cancelAction)
present(actionSheet, animated: true, completion: nil)
}
}
我想从 viewControllerA 调用这个扩展
let actionView = UIAlertController()
class viewControllerA: UIViewController {}
private extension viewControllerA {
func alertBottomSheat() {
actionView.action(mes: "Update",tit: "Update only",tit2: "Update All", operation1:saveEvent(),operation2:saveEvent())
}
@IBAction func deleteEventButtonClicked(_ sender: Any) {
actionView.action(mes: "delete ",tit: "Delete only",tit2: "Delete All ",operation1:deleteEvent(),operation2:deleteEvent(deleteAll: true))
}
}
Q1- 我是从 viewControllerA 扩展中调用扩展的正确方法吗？
Q2- 请告诉我如何在此行中使用闭包在动作函数参数中传递函数？
actionView.action(mes: "delete ",tit: "Delete only",tit2: "Delete All ",operation1:deleteEvent(),operation2:deleteEvent(deleteAll: true))
以及如何在此行的操作表处理程序中使用闭包
let EButton = UIAlertAction(title:tit ,
style: .default,
handler: { _ in
operation1
})
您首先需要为UIViewController而不是创建一个扩展UIAlertController
另外，为函数设置正确的闭包参数，然后像这样调用函数。
extension UIViewController {
func action(message: String, firstTitle: String, secondTitle: String, firstAction: (() -> Void)? = nil, secondAction: (() -> Void)? = nil) {
let actionSheet = UIAlertController(title: "", message: message, preferredStyle: .actionSheet)
let eButton = UIAlertAction(title: firstTitle ,
style: .default,
handler: {_ in firstAction?()})
let allEButton = UIAlertAction(title: secondTitle,
style: .default ,
handler: {_ in secondAction?()})
let cancelAction = UIAlertAction(title: "Cancel",
style: .cancel,
handler: nil)
[eButton, allEButton, cancelAction].forEach { $0.setValue(UIColor.red, forKey: "titleTextColor")}
actionSheet.addAction(eButton)
actionSheet.addAction(allEButton)
actionSheet.addAction(cancelAction)
present(actionSheet, animated: true, completion: nil)
}
}
用法
private extension viewControllerA {
func alertBottomSheat() {
self.action(message: "Update", firstTitle: "Update only", secondTitle: "Update All", firstAction: saveEvent, secondAction: saveEvent)
}
@IBAction func deleteEventButtonClicked(_ sender: Any) {
self.action(message: "delete ", firstTitle: "Delete only", secondTitle: "Delete All ", firstAction: { self.deleteEvent()}, secondAction: { self.deleteEvent(deleteAll: true) })
}
func saveEvent() {
}
func deleteEvent(deleteAll: Bool = false) {
}
}
注意：固定编码标准规则和变量名称。
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