如何在Swift中使用函数类型参数定义函数

Question

I could define a function like this

func doWithAction(action: ()-> void) {
    // something
}

However, when I use the function, the auto-completion of Xcode give me a block/closure

self.addPullToRefreshControllerWithAction { () -> void in

}

I know closure and function are something same in Swift, but I want to lead the one who use this function to pass a function in, not a block. The reason why I do this is I want this function to behave like a selector and a delegation

Answer 1

yes, closure and functions are practically the same in swift, so if the function expects a closure, you can pass a function with the same signature as a parameter instead. like this

func iAmAFunc(() -> Void) -> Void {
    //do stuff
}

func funcThatTakesVoidAndReturnsVoid() -> Void {
    //do stuff
}

var closureThatTakesVoidAndReturnsVoid: () -> Void = { }

iAmAFunc(funcThatTakesVoidAndReturnsVoid)
iAmAFunc(closureThatTakesVoidAndReturnsVoid)