在希望的田野上

摘要： Notice in Figure 22.2 that each view has a layer and each view is its layer’s delegate. We’ll come back to the delegate relationship later in the chap... 阅读全文

摘要： NSValue valueWithNonretainedObjecthttp://stackoverflow.com/questions/8748736/weak-object-in-an-nsdictionaryhttp://stackoverflow.com/questions/3618479/... 阅读全文