class_copyIvarList 和 class_copyPropertyList的区别

新建一个类 MessageModel

1、在MessageModel.h文件中声明属性

@property (nonatomic, copy) NSString *sender;

2、在MessageModel.m文件中，实现类扩展并添加属性

@interface MessageModel ()

@property (nonatomic, copy) NSString *sendTime;
@end

3、在MessageModel.m文件中的实现中添加成员变量

@implementation MessageModel
{
    NSString *timeInterval;
}
@end

4、ViewController中获取MessageModel的Ivar和Property

    MessageModel *message = [[MessageModel alloc] init];
    
    /// 获取 ivar
    unsigned int ivarCount;
    Ivar *ivar_list = class_copyIvarList(message.class, &ivarCount);
    for (int i = 0; i  < ivarCount; i++) {
        Ivar ivar = ivar_list[i];
        const char *cName = ivar_getName(ivar);
        NSLog(@"--> ivar name: %@", [NSString stringWithUTF8String:cName]);
    }
    NSLog(@"\n\n");
    /// 获取 property
    unsigned int propertyCount;
    objc_property_t *property_list = class_copyPropertyList(message.class, &propertyCount);
    for (int i = 0; i < propertyCount; i++) {
        objc_property_t property = property_list[i];
        const char *cName = property_getName(property);
        NSLog(@"--> property name: %@", [NSString stringWithUTF8String:cName]);
    }

输入结果为

image.png

5、由此可见，class_copyIvarList获取的是类中的成员变量，包括.h和extension中声明属性的成员变量，以及实现文件中{}内的成员变量，而class_copyPropertyList获取的则是.h和extension中声明属性。

6、引申，如果添加一个分类，在分类中添加一个属性那么两个打印结果是否有不同

创建一个分类MessageModel+Input并添加属性，同时在.m文件通过runtime关联属性

@interface MessageModel (Input)

@property (nonatomic, copy) NSString *inputName;

@end

@implementation MessageModel (Input)


- (void)setInputName:(NSString *)inputName {
    objc_setAssociatedObject(self, @selector(inputName), inputName, OBJC_ASSOCIATION_COPY_NONATOMIC);
}

- (NSString *)inputName {
    return objc_getAssociatedObject(self, @selector(inputName));
}
@end

输出结果如下

image.png