Swift 3中带有字符串的参数的responseToSelector/performSelector [英] respondToSelector / performSelector with parameter from a string in Swift 3

问题描述

我必须调用类的方法.此方法可能存在或不存在. 我正在寻找2小时后的解决方案. 以下在没有参数sayHello()

I have to call method of a class. This method potentially exists or not. I'm looking for a solution from 2 hours. The following works without parameter sayHello()

我上课了:

class myClass: NSObject {
    func say(something:String){
        print("I say : \(something)")
    }

    func sayHello(){
        print("Hello")
    }
}

第一步:从带有参数的字符串中创建选择器

1st step : Create a selector from a string with a parameter

let selector = NSSelectorFromString("sayHello" ) 
let selectorWithParam = NSSelectorFromString("say:" ) 

第二步:测试该方法是否存在

2nd step : Test if the method exist

self.bot?.responds(to: selector)// true
self.bot?.responds(to: selectorWithParam) // false        

它不适用于参数！

此外，我尝试使用Swift3 #selector，但是我找不到从字符串输入方法的方法

Beside, i tried with the Swift3 #selector , but I found no way to enter a method from a string

推荐答案

Swift方法

func say(something:String)

映射为Objective-C，

is mapped to Objective-C as

- (void)sayWithSomething:(NSString * _Nonnull)something;

，因此正确的选择器应该是

and therefore the correct selector would be

let selectorWithParam = NSSelectorFromString("sayWithSomething:" )

使用#selector不太容易出错:

let selectorWithParam = #selector(myClass.say(something:))

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