Block 与 Closure

OC 的 Block 与 Swift 的 Closure

相互转化

1. Closure 转 Block

   1let closure: (String) -> Void = { str in
   2
   3}
   4let block = closure as @convention(block) (String) -> Void
   5let blockObject = unsafeBitCast(block, to: AnyObject.self)
   

2. Block 转 Closure

   1typealias closureType = @convention(block) (String) -> Void
   2// OC_block 为 OC 定义的 block
   3let closure = unsafeBitCast(OC_block as AnyObject, to: closureType.self)