iOS-實現對象拷貝【對象拷貝】

對象引用 NSCopying 代理

.h

@interface xk : NSObject <NSCopying>

@property (nonatomic, copy) NSString *string1;

@property (nonatomic, copy) NSString *string2

@end

實現代理【拷貝】方法

.m

- (id)copyWithZone:(nullable NSZone *)zone {

 xk *xk1= [[[self class] allocWithZone:zone] init];

xk1.string1 = [self.string1 copy];

 xk1.string2 = [self.string2 copy];

return xk1;

}