Swift闭包(Closure)回调传值
场景:
A页面present到B页面，B页面dismiss到A页面时，把值传递给A页面
1. 在B页面定义一个闭包
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| import UIKit
// 定义一个闭包类型
typealias callBackCompletion = (_ str: String, _ age: Int) -> Void
class NextViewController: UIViewController {
// 定义一个变量，把闭包当变量使用
fileprivate var callBack: callBackCompletion?
private var name: String?
private var age: Int?
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if self.callBack != nil {
self.callBack!(self.name! + "11", self.age! + 22)
self.dismiss(animated: true, completion: nil)
}
}
// MARK: - 回调函数
func setCallBackValue(name: String, age: Int, callBack: @escaping callBackCompletion) {
self.name = name
self.age = age
self.callBack = callBack
}
}
|
2.在A页面得到值
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| override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
let vc = NextViewController()
vc.setCallBackValue(name: "Ghost", age: 20) { (name, age) in
print("\(name, age)")
}
self.present(vc, animated: true, completion: nil)
}
|