Objective-C 中的友元类

Objective-C 中的友元类

objective-c
// MyClass.h
@class FriendClass; // 声明友元类
@interface MyClass : NSObject
- (void)publicMethod;
@end
// FriendClass.h
@interface FriendClass : NSObject
- (void)accessPrivateMemberOfClass:(MyClass *)myClass;
@end
// MyClass.m
#import "MyClass.h"
#import "FriendClass.h"
@interface MyClass ()
@property (nonatomic, assign) NSInteger privateMember;
@end
@implementation MyClass
- (void)publicMethod {
    FriendClass *friend = [[FriendClass alloc] init];
    [friend accessPrivateMemberOfClass:self];
}
@end
// FriendClass.m
#import "FriendClass.h"
#import "MyClass.h"
@implementation FriendClass
- (void)accessPrivateMemberOfClass:(MyClass *)myClass {
    myClass.privateMember = 10; // 可以访问 MyClass 的私有成员
}
@end