/*

//----------------------------------------

2.设计2个类，类之间的关系自拟（比如继承、组合）

1> 身材数据

(1)属性

* 身高

* 体重

* 手长

* 脚长

(2)方法

* 属性相应的set和get方法

2> 人

(1)属性

* 年龄

* 身高

* 体重

* 手长

* 脚长

(2)方法

* 属性相应的set和get方法

*/

#import <Foundation/Foundation.h>

@interface Body : NSObject

{

    double _height;

    double _weight;

    double _hands;

    double _foots;

}

- (void)setHeight:(double)height;

- (double)height;

- (void)setWeight:(double)Weight;

- (double)weight;

- (void)setHands:(double)hands;

- (double)hands;

- (void)setFoots:(double)foots;

- (double)foots;

@end

@implementation Body

- (void)setHeight:(double)height

{

    self->_height = height;

}

- (double)height

{

    return self->_height;

}

- (void)setWeight:(double)weight

{

    self->_weight = weight;

}

- (double)weight

{

   return self->_weight;

}

- (void)setHands:(double)hands

{

    self->_hands = hands;

}

- (double)hands

{

    return self->_hands;

}

- (void)setFoots:(double)foots

{

    self->_foots = foots;

}

- (double)foots

{

    return self->_foots;

}

@end

@interface Person : NSObject

{

    int _age;

    Body * _body;

}

- (void)setAge:(int)age;

- (int)age;

- (void)setBodyofHeight:(double)height ofWeight:(double)weight ofHands:(double)hands ofFoots:(double)foots;

- (Body *)body ;

@end

@implementation Person

- (void)setAge:(int)age

{

    self->_age = age;

}

- (int)age

{

    return self->_age;

}

- (void)setBodyofHeight:(double)height ofWeight:(double)weight ofHands:(double)hands ofFoots:(double)foots

{

    //_body = [body setHeight:height];

    [self->_body setHeight:height];

    [self->_body setWeight:weight];

    [self->_body setHands:hands];

    [self->_body setFoots:foots];

}

- (Body *)body

{

    return self->_body;

}

@end

int main()

{

    Person * p = [Person new];

    [p setBodyofHeight:173.5 ofWeight:58.0 ofHands:13.2 ofFoots:14.3];

   

    Body * b = [p body];

    NSLog(@"b->_height=%f,b->_weight=%f,b->_hands=%f,b->_foots=%f",[b height],[b weight], [b hands], [b foots]);

    return 0;

}

b->_height=0.000000,b->_weight=0.000000,b->_hands=0.000000,b->_foots=0.000000

为毛输出结果都为0！

求大师指点！！

你Person类里的属性_body这个对象在你创建Person对象的时候_body里面的值是空的，即nil。
之后你再_body的set方法里用[self->_body setHeight:height];，这是没有意义的。相当于[nil setHeight:height];
你应该在_body的set方法里先创建一个Body对象，再把对象赋给_body。
代码如下：

1. - (void)setBodyofHeight:(double)height ofWeight:(double)weight ofHands:(double)hands ofFoots:(double)foots
   
2. {
   
3.     Body *b = [Body new];
   
4.     [b setHeight:height];
   
5.     [b setWeight:weight];
   
6.     [b setHands:hands];
   
7.     [b setFoots:foots];
   
8.     self->_body = b;
   
9. }

复制代码

弹琴骚年 发表于 2014-10-18 22:26
你Person类里的属性_body这个对象在你创建Person对象的时候_body里面的值是空的，即nil。
之后你再_body的s ...

嗯，已经解决了！方法的架构不好，要加个形参(Body *)body

加油ahhhhhhhhhhhhh……

上面代码的写法，还是没有转到面向对象，set设置方法形参应该只设置，要调用该方法的对象的属性，即可！用到的各个类对象，在主函数main中创建并初始化，而不是全部集中在一个方法中，就像上面的
- (void)setBodyofHeight:(double)height ofWeight:(double)weight ofHands:(double)hands ofFoots:(double)foots
{

    //_body = [body setHeight:height];
    [self->_body setHeight:height];
    [self->_body setWeight:weight];
    [self->_body setHands:hands];
    [self->_body setFoots:foots];
}
应该是
- (void)setBodyofHeight:(Body*)body
{
    _body = body;
}

好长的一串代码，可惜没装苹果系统，运行不了。