这是一个类中的函数,可让您进行双击和单击手势。它在 Swift 2.3 中工作正常,但转换到 Swift 3 后会抛出一些错误。我一生都无法理解/弄清楚。我评论了它们发生的地方。
// UIShortTapGestureRecognizer.swift
//
//
import Foundation
import UIKit
func delayHelper(_ time:TimeInterval, task:@escaping ()->()) -> DelayTask? {
func dispatch_later(_ block:@escaping ()->()) {
DispatchQueue.main.asyncAfter(
deadline: DispatchTime.now() + Double(Int64(time * Double(NSEC_PER_SEC))) / Double(NSEC_PER_SEC),
execute: block)
}
var closure: ()->()? = task
var result: DelayTask?
let delayedClosure: DelayTask = {
cancel in
//Initializer for conditional binding must have Optional type, not '() -> ()?'
if let internalClosure = closure {
if (cancel == false) {
DispatchQueue.main.async(execute: internalClosure)
}
}
// here it says Nil cannot be assigned to type '() -> ()?'
closure = nil
result = nil
}
result = delayedClosure
dispatch_later {
if let delayedClosure = result {
delayedClosure(false)
}
}
return result;
}
func cancel(_ task:DelayTask?) {
task?(true)
}
}
尝试使用:var closure: (()->())? = task
本文内容由网友自发贡献,版权归原作者所有,本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容,请联系:hwhale#tublm.com(使用前将#替换为@)