swift 闭包的简单使用模版

闭包的定义
typealias BPCallBack = (Any) -> Void

var callBack2 : BPCallBack?

闭包的声明
if ((self.callBack2) != nil){
self.callBack2!(indexPath.row)
}

闭包的实现
self.callBack2 = {[weak self](object : Any?) in
var index : Int = object as! Int
if let strongself = self {
index += 1
print(index)
}
}