iOS&Swift&OC 闭包和Block的相互转化

一、Swift的闭包 -> OC的block

//  将closure类型转化为block类型（Swift的闭包 -> OC的block）
        let closure = {
            (str: String)->Void in

        }
        let block = closure as @convention(block) (String) -> Void
        let blockObject = unsafeBitCast(block, to: AnyObject.self)
        // 转化完毕blockObject就是一个block了，就可以在OC中正常使用了，也可以放入params中传递了
        let params = ["callback":blockObject] as [AnyHashable:Any]
        

二、OC的block -> Swift的闭包

 // 将block转化为closure类型（OC的block -> Swift的闭包）
        // callblock是OC的带一个字符串参数的block
        // let testBlock = actionParams["callblock"]
        typealias ClosureType = @convention(block) (String) -> Void
        let blockPtr = UnsafeRawPointer(Unmanaged<AnyObject>.passUnretained(testBlock as AnyObject).toOpaque())
        let closure = unsafeBitCast(blockPtr, to: ClosureType.self)

        // closure就是转化过后的闭包
        closure("测试")