// Son.m#import "Son.h"@interface Son ()// 将属性放在.m文件中，使之成为私有属性@property (nonatomic, copy) NSString *name;@end

// Father.m#import "Father.h"#import "Son.h"#import 
    
     @implementation Father#pragma mark - KVC 方式访问和修改私有变量- (void)printSonNameWithKVC{    Son *son = [[Son alloc] init];        // 修改前    NSString *name = [son valueForKey:@"name"];    NSLog(@"-name:%@", name);        // 修改后    [son setValue:@"Jabit" forKey:@"name"];    NSString *nameReset = [son valueForKey:@"name"];    NSLog(@"-nameReset:%@", nameReset);}#pragma mark - Runtime 方式访问和修改私有变量- (void)printSonNameWithRuntime{    Son *son = [[Son alloc] init];        unsigned int count = 0;    Ivar *members = class_copyIvarList([Son class], &count);    for (int i = 0; i < count; i++) {        Ivar ivar = members[i];        const char *memberName = ivar_getName(ivar);        const char *memberType = ivar_getTypeEncoding(ivar);        //依次打印属性名称和属性类型        NSLog(@"%s : %s", memberName, memberType);                if (strcmp(memberName, "_name") == 0) {            // 修改前            NSString *name = (NSString *)object_getIvar(son, members[i]);            NSLog(@"-name:%@", name);                        // 修改后            object_setIvar(son, members[i], @"Jabit");            NSString *nameReset = (NSString *)object_getIvar(son, members[i]);            NSLog(@"-nameReset:%@", nameReset);                        break;        }    }}@end