1. /* 学生
   
2. */
   
3. #import <Foundation/Foundation.h>
   
4. typedef enum
   
5. {
   
6.     SexMan,
   
7.     SexWoman
   
8. }Sex;
   
9. typedef struct
   
10. {
    
11.     int year;
    
12.     int mouth;
    
13.     int day;
    
14. }Date;
    
15. typedef enum
    
16. {
    
17.     ColorBlack,
    
18.     ColorRed,
    
19.     ColorGreen
    
20. }Color;
    
21. 
    
22. @interface  Dog : NSObject
    
23. {
    
24.     @public
    
25.     double weight;
    
26.     Color curColor;
    
27. }
    
28. -(void)eat;
    
29. -(void)run;
    
30. 
    
31. @end
    
32. 
    
33. @implementation Dog
    
34. - (void) eat
    
35. {
    
36.     weight+=1;
    
37.     NSLog(@"狗吃完这次后体重是%f",weight);
    
38. }
    
39. 
    
40. - (void) run
    
41. {
    
42.     weight-=1;
    
43.     NSLog(@"狗跑完这次体重是%f",weight);
    
44. }
    
45. 
    
46. @end
    
47. 
    
48. @interface Student : NSObject
    
49. {
    
50.     @public
    
51.     Sex sex;
    
52.     Date birthday;
    
53.     double weight;
    
54.     Color favColor;
    
55.     char *name;
    
56.     Dog *dog;
    
57. }
    
58. - (void)eat;
    
59. - (void)run;
    
60. - (void)print;
    
61. - (void)liuDog;
    
62. - (void)weiDog;
    
63. @end
    
64. 
    
65. @implementation Student
    
66. - (void) eat
    
67. {
    
68.     weight+=1;
    
69.     NSLog(@"吃完这次后体重是%f",weight);
    
70. }
    
71. 
    
72. - (void) run
    
73. {
    
74.     weight-=1;
    
75.     NSLog(@"跑完这次体重是%f",weight);
    
76. }
    
77. -(void) print
    
78. {
    
79.     NSLog(@"性别=%d, 颜色=%d, 生日=%d-%d-%d 姓名%s",sex,favColor,birthday.year,birthday.mouth,birthday.day,name);
    
80. }
    
81. - (void)liuDog
    
82. {
    
83.     [dog run];
    
84. }
    
85. - (void)weiDog
    
86. {
    
87.     [dog eat];
    
88. }
    
89. 
    
90. @end
    
91. 
    
92. int main()
    
93. {
    
94.     Student *s = [Student new];
    
95.    
    
96.     //Dog *d = [Dog new]; 这是视频中的写法，给类中的类赋值，必须用这种方式？？
    
97.     //d->curColor = ColorGreen;
    
98.     //d->weight = 20;
    
99.     //s->dog = d;
    
100.     s->dog->weight = 100;
     
101.     s->dog->curColor = ColorGreen;
     
102.     [s liuDog];
     
103.     [s weiDog];
     
104.    
     
105.     return 0;
     
106. }

复制代码

编译连接没有错误，但是执行的时候出现  Segmentation fault: 11的提示  什么意思

没人回答呢

//Dog *d = [Dog new]; 这是视频中的写法，给类中的类赋值，必须用这种方式？？
    //d->curColor = ColorGreen;
    //d->weight = 20;
    //s->dog = d;
    s->dog->weight = 100;
    s->dog->curColor = ColorGreen;

这段代码必须用你注释的一段代码，不能 s->dog->weight = 100;
    s->dog->curColor = ColorGreen;这样写。。。。视频中老师专门强调过得。。。。

应该是这//s->dog = d;这段不能注释掉的原因，

还有- (void)liuDog:(Dog *)d
{
    [d run];
}
- (void)weiDog:(Dog *)d
{
    [d eat];
}这两个方法要加参数，没有参数怎么知道，是哪只狗呢？？

好深奥啊

liboy 发表于 2015-3-17 16:46
还有- (void)liuDogDog *)d
{
    [d run];

这刚才说错了我，搞错了不需要改，不好意思，呵呵:#