iOS私有属性的访问与修改

// 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 <objc/runtime.h>

@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