如何在Swift数组中存储闭包
如何在Swift数组中存储闭包
提问于 2018-10-11 10:12:59
我想将闭包存储在数组中。但我不知道该怎么做，否则我的想法是完全错误的。使用下面所示的设置，我得到了一个错误：
Cannot convert value of type '(Reader) -> (URL) -> ()' to expected element type '(URL) -> ()'我不明白。我的班级：
class Reader {
let fileNamesActions:[( filename:String, action:(URL) -> () )] = [
(filename:"goodStories.txt", action: readGoodStories),
(filename:"badStories.txt", action: readBadStories),
(filename:"stupidStories", action: readStupidStories)]我宣布了这样的职能：
func readGoodStories(from url:URL) {
//read, do whatever i want with url
}
...我称他们为：
init (with url:URL) {
for (filename, action) in fileNamesActions {
action(url.appendingPathComponent(filename))
}
}回答 1
Stack Overflow用户
回答已采纳
发布于 2018-10-11 11:23:23
将fileNamesActions的声明更改为lazy var，因为您正在访问其分配中的class成员，
class Reader {
lazy var fileNamesActions:[( filename:String, action:(URL) -> () )] = [
(filename:"goodStories.txt", action: readGoodStories),
(filename:"badStories.txt", action: readBadStories),
(filename:"stupidStories", action: readStupidStories)]
init (with url:URL) {
for (filename, action) in fileNamesActions {
action(url.appendingPathComponent(filename))
}
}
func readBadStories(from url:URL) {
print(url.path)
}
func readStupidStories(from url:URL) {
print(url.path)
}
func readGoodStories(from url:URL) {
print(url.path)
}
}使用
let reader = Reader(with: URL(string: "www.xxxxxxxxxx.com")!)输出
www.xxxxxxxxxx.com/goodStories.txt
www.xxxxxxxxxx.com/badStories.txt
www.xxxxxxxxxx.com/stupidStories页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/52757523
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