Visitor(Chapter 15 of Pro Objective-C Design Patterns for iOS)
摘要：
The Visitor pattern represents an operation to be performed on the elements of an objectstructure. Visitor lets you define a new operation without changing the classes of the elements onwhich it operates. 阅读全文
posted @ 2012-05-03 13:48 Ray Z 阅读(284) 评论(0) 推荐(0) 编辑
