注意点:如果不是 NSObject或者其子类,那么需要将 替换方法前 + dynamic 可动态派发
extension UIButton {
classfunc Mrshan_swizzleSendAction() {
struct xxx_swizzleToken {
staticvar onceToken : dispatch_once_t =0
}
//设定这个方法只是执行一次,在第一个uibutton初始化的时候执行这个方法,嘻嘻
dispatch_once(&xxx_swizzleToken.onceToken) {
let cls:AnyClass! = UIButton.self
let originalSelector =Selector("sendAction:to:forEvent:")
let swizzledSelector =Selector("Mrshan_sendAction:to:forEvent:")
let originalMethod =class_getInstanceMethod(cls,originalSelector)
let swizzledMethod =class_getInstanceMethod(cls,swizzledSelector)
method_exchangeImplementations(originalMethod,swizzledMethod)
let cls1 =twoViewController.self
let originSelect1 =Selector("one")
let swizzleSelect1 =Selector("two")
let originMethod1 =class_getInstanceMethod(cls1,originSelect1)
let swizzleMethod1 =class_getInstanceMethod(cls1,swizzleSelect1)
method_exchangeImplementations(originMethod1,swizzleMethod1)
}
}
/**
这个是被调换的方法的实现
- parameter action: <#action description#>
- parameter to: <#to description#>
- parameter forEvent: <#forEvent description#>
*/
publicfunc Mrshan_sendAction(action: Selector,
to: AnyObject!,
forEvent: UIEvent!)
{
//计数器+=1
xxx_buttonTapCounter.count +=1
print(xxx_buttonTapCounter.count)
//这里并不是调用的自己,因为在执行这个方法的时候,Mrshan_sendAction 和 sendAction 的实现已经调换了,所以执行的是原来的button的点击事件
Mrshan_sendAction(action,to: to,forEvent: forEvent)
}
/**
重写构造方法,并且确认构造者是uibutton
- returns: <#return value description#>
*/
overridepublic classfunc initialize() {
//别用断言。。老实一点用IF
ifself != UIButton.self {
return
}
UIButton.Mrshan_swizzleSendAction()
}
}
/**
* button的点击计数器
*/
struct xxx_buttonTapCounter {
staticvar count: Int =0
}