如何从已经存在的类创建自定义类？ （现有类不支持NSCoding）

Question

What I'm trying to do is convert an EKEvent into NSData , and then convert it back into an EKEvent .

I looked around and noticed that in order to use NSKeyedArchiver , the class must conform to the NSCoding protocol. I also found that if I was creating a custom class, I could make it conform to the NSCoding protocol by implementing encodeWithCoder: on such a custom class.

Essentially, I assume that in order to convert my EKEvent to NSData and back, I will need to create a custom class (let us call it CustomEvent ) I need to do the following:

EKEvent --> CustomEvent --> NSData --> CustomEvent --> EKEvent

Can I get any help on learning how to create a custom class which DUPLICATES an existing class with the exception that I implement encodeWithCoder: to make it conform to NSCoding ?

I'm looking at EKEvent.h, and I know that it involves other classes which I must also duplicate (because they too don't conform to NSCoding ). Can anyone send me a tutorial link or help me out?

Thanks in advance!

Answer 1

What you're describing appears to be a subclass .

However, in Objective-C, you have the simpler option of defining a category on an existing class to add the functionality you want.