记录下今天学的东西，激励自己前进！{:3_63:}

定义了两个类，Point2D类 和 Circle 类，其中 Circle类中属性包含 Point2D类，各个文件单独编译，统一链接。

Point2D.h文件：（Point2D类的声明)

1. #import <Foundation/Foundation.h>
   
2. 
   
3. @interface Point2D : NSObject
   
4. {
   
5.     int _x;
   
6.     int _y;
   
7. }
   
8. 
   
9. //_x的setter和getter
   
10. - (void)setX:(int)x;
    
11. - (int)x;
    
12. 
    
13. //同时设置_x 和 _y
    
14. - (void)setX:(int)x andY:(int)y;
    
15. 
    
16. //_y的setter和getter
    
17. - (void)setY:(int)y;
    
18. - (int)y;
    
19. 
    
20. //两点之间距离的方法
    
21. + (double)distanceBetweenPoint1:(Point2D *)p1 andPoint2:(Point2D *)p2;
    
22. - (double)distanceWithOther:(Point2D *)p;
    
23. @end
    

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Point2D.m （Point2D类的实现）

1. #import "Point2D.h"
   
2. #import <math.h>
   
3. 
   
4. @implementation Point2D
   
5. //_x的setter和getter
   
6. - (void)setX:(int)x
   
7. {
   
8.     _x = x;
   
9. }
   
10. - (int)x
    
11. {
    
12.     return _x;
    
13. }
    
14. //_y的setter和getter
    
15. - (void)setY:(int)y
    
16. {
    
17.     _y = y;
    
18. }
    
19. - (int)y
    
20. {
    
21.     return _y;
    
22. }
    
23. //同时设置x和y的方法
    
24. - (void)setX:(int)x andY:(int)y
    
25. {
    
26.     _x = x;
    
27.     _y = y;
    
28. }
    
29. 
    
30. //两点之间的距离方法
    
31. + (double)distanceBetweenPoint1:(Point2D *)p1 andPoint2:(Point2D *)p2
    
32. {
    
33.     int m = [p1 x] - [p2 x];
    
34.     int n = [p1 y] - [p2 y];
    
35.     double distance = sqrt(m*m + n*n);
    
36.     return distance;
    
37.    
    
38. }
    
39. //与其他点之间的距离
    
40. - (double)distanceWithOther:(Point2D *)p
    
41. {
    
42.     return [Point2D distanceBetweenPoint1:self andPoint2:p];
    
43. }
    
44. 
    
45. @end
    

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Circle.h文件  (Circle 类的声明）

1. #import <Foundation/Foundation.h>
   
2. #import "Point2D.h"
   
3. 
   
4. //定义一个圆类
   
5. @interface Circle : NSObject
   
6. {
   
7.     Point2D *_circlePoint;        //圆心，Point2D对象
   
8.     double _radius;               //半径
   
9. }
   
10. 
    
11. //_circlePoint的setter和getter
    
12. - (void)setCirclePoint:(Point2D *)circlePoint;
    
13. - (Point2D *)circlePoint;
    
14. 
    
15. //radius的setter和getter方法
    
16. - (void)setRadius:(double)radius;
    
17. - (double)radius;
    
18. 
    
19. //判断是否与其他圆相交的方法
    
20. + (BOOL)isIntersectBetweenCircle1:(Circle *)c1 andCircle2:(Circle *)c2;
    
21. - (BOOL)isIntersectWithOther:(Circle *)c1;
    
22. @end
    

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Circle.m文件 (Circle类的实现)

1. #import "Circle.h"
   
2. #import "Point2D.h"
   
3. 
   
4. 
   
5. @implementation Circle
   
6. //_circlePoint的setter和getter
   
7. - (void)setCirclePoint:(Point2D *)circlePoint
   
8. {
   
9.     _circlePoint = circlePoint;
   
10. }
    
11. - (Point2D *)circlePoint
    
12. {
    
13.     return _circlePoint;
    
14. }
    
15. 
    
16. //radius的setter和getter方法
    
17. - (void)setRadius:(double)radius
    
18. {
    
19.     _radius = radius;
    
20. }
    
21. - (double)radius
    
22. {
    
23.     return _radius;
    
24. }
    
25. 
    
26. //判断两个圆是否相交
    
27. + (BOOL)isIntersectBetweenCircle1:(Circle *)c1 andCircle2:(Circle *)c2
    
28. {
    
29.     return [c1 isIntersectWithOther:c2];
    
30. }
    
31. - (BOOL)isIntersectWithOther:(Circle *)c1
    
32. {
    
33.     //distance圆心距 小于 radiusSum半径和 则两圆相交
    
34.     double distance = [Point2D distanceBetweenPoint1:[self circlePoint] andPoint2:[c1 circlePoint]];
    
35.     double radiusSum = [self radius] + [c1 radius];
    
36.     return distance < radiusSum;
    
37. }
    
38. 
    
39. @end
    

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main.m文件 (项目的入口)

1. #import "Point2D.h"
   
2. #import "Circle.h"
   
3. 
   
4. int main()
   
5. {
   
6.     //定义一个圆c1 并设置其属性
   
7.     Point2D *p1 = [Point2D new];
   
8.     [p1 setX:10 andY:5];
   
9.     Circle *c1 = [Circle new];
   
10.     [c1 setRadius:2];
    
11.     [c1 setCirclePoint:p1];
    
12.    
    
13.     //定义一个圆c2 并设置其属性
    
14.     Point2D *p2 = [Point2D new];
    
15.     [p2 setX:7 andY:9];
    
16.     Circle *c2 = [Circle new];
    
17.     [c2 setCirclePoint:p2];
    
18.     [c2 setRadius:10];
    
19.    
    
20.     //调用 isIntersectWithOther方法 判断两圆是否相交
    
21.     //返回值为 YES 证明两圆相交  返回值是 NO 则两圆不相交
    
22.     BOOL flag = [c1 isIntersectWithOther:c2];
    
23.     NSLog(@"%d",flag);
    
24.     return 0;
    
25. }

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   所有文件都可以用 cc -c 命令单独编译生成 .o文件，最后用 cc main.o Point2D.o Circle.o -framework Foundation 命令链接，生成可执行文件a.out