Question

Objective-c复制方法是否执行对象的深层复制？

NSObject *clone = [self copy];

Answer 1

NSObject *clone = [self copy];

不要执行深层复制，但会是浅层复制。

您需要像这样实施NSCopying协议

//ContactCard.h
@interface ContactCard : NSObject<NSCopying>
{
    NSString* name;
    NSString* email;
}
...
-(id)copyWithZone:(NSZone *)zone;
@end

//ContactCard.m
@implementation ContactCard
...
-(id)copyWithZone:(NSZone *)zone
{
    ContactCard* cc = [[ContactCard allocWithZone:zone]init];
    cc->email = [email copy];
    cc->name = [name copy];
    return cc;
}
...
@end

您可以在enter link description here上阅读更多内容或者在NSCopying上引用Apple docs

Answer 2

这可能会有所帮助。对于任何自定义对象的深层副本，我们需要在该类中采用NSCopying协议。 How to copy an object in objective c

如何执行Objective-C深层复制

2 个答案: