1.Car.h文件
#import <Foundation/Foundation.h>
//如果A类.h引入B类的.h文件,B类.h文件又引入A类的头文件,就会导致头文件循环引入的错误
//解决方案:
//以后只有两种情况需要在.h里面引其他的头文件, 1是继承, 2是协议
//除此之外需要引头文件,全部到.m文件中引入 .h中如果要使用该类型,使用@class关键字,@class的作用是告诉编译器他是一个类型,并不会把该文件中的内容引入过来
@class Engine,Tire; //@class
@interface Car : NSObject
{ //定义汽车类实例变量
NSString * _brand;
NSString * _color;
CGFloat _price;
Engine * _engine;//引擎
Tire * _tire;//轮胎
}
汽车设置器与访问器
- (void)setBrand:(NSString *)brand;
- (NSString *)brand;
- (void)setCplor:(NSString *)color;
- (NSString *)color;
- (void)setPrice:(CGFloat)price;
- (CGFloat)price;
//自定义初始化方法
- (id)initwithBrand:(NSString *)brand;
- (id)initwithColor:(NSString *)color;
- (id)initwithPrice:(CGFloat)price;
- (id)initwithBrand:(NSString *)brand
color:(NSString *)color;
- (id)initwithBrand:(NSString *)brand
price:(CGFloat)price;
- (id)initwithColor:(NSString *)color
price:(CGFloat)price;
- (id)initwithBrand:(NSString *)brand
color:(NSString *)color
price:(CGFloat)price;
//汽车启动方法
- (void)start;
- (void)setEngine:(Engine *)engine;//汽车发动机设置器与访问器
- (Engine *)engine;
- (void)setTire:(Tire *)tire;//轮胎设置器与访问器
- (Tire *)tire;
@end
2.Car.m文件
#import "Car.h"
#import "Engine.h"
#import "Tire.h" //注意此处要引入头文件
@implementation Car
- (void)setBrand:(NSString *)brand
{
_brand = brand;
}
- (NSString *)brand
{
return _brand;
}
- (void)setCplor:(NSString *)color
{
_color = color;
}
- (NSString *)color
{
return _color;
}
- (void)setPrice:(CGFloat)price
{
_price = price;
}
- (CGFloat)price
{
return _price;
}
- (id)initwithBrand:(NSString *)brand
{
_brand = brand;
return self;
}
- (id)initwithColor:(NSString *)color
{
_color = color;
return self;
}
- (id)initwithPrice:(CGFloat)price
{
_price = price;
return self;
}
- (id)initwithBrand:(NSString *)brand
color:(NSString *)color
{
_brand = brand;
_color = color;
return self;
}
- (id)initwithBrand:(NSString *)brand
price:(CGFloat)price
{
_brand = brand;
_price = price;
return self;
}
- (id)initwithColor:(NSString *)color
price:(CGFloat)price
{
_color = color;
_price = price;
return self;
}
- (id)initwithBrand:(NSString *)brand
color:(NSString *)color
price:(CGFloat)price
{
_brand = brand;
_color = color;
_price = price;
return self;
}
- (void)setEngine:(Engine *)engine
{
_engine = engine;
}
- (Engine *)engine
{
return _engine;
}
- (void)setTire:(Tire *)tire
{
_tire = tire;
}
- (Tire *)tire
{
return _tire;
}
- (void)start
{
BOOL result = [_engine fire]; //调用发动机点火行为
//点火成功则轮胎转动
if (result) { //result = 1则调用轮胎turn(转动)行为
[_tire turn];
}
else{
NSLog(@"请重试.....!");
}
}
@end
3.Tire.h
#import <Foundation/Foundation.h>
@interface Tire : NSObject
{
NSString * _brand;//品牌
CGFloat _size;//尺寸
}
- (void)turn;//转动
- (void)setBrand:(NSString *)brand;
- (NSString *)brand;
- (void)setSize:(CGFloat)size;
- (CGFloat)size;
- (id)initwithBrand:(NSString *)brand
size:(CGFloat)size;
@end
4.Tire.m
#import "Tire.h"
@implementation Tire
- (void)setBrand:(NSString *)brand
{
_brand = brand;
}
- (NSString *)brand
{
return _brand;
}
- (void)setSize:(CGFloat)size
{
_size = size;
}
- (CGFloat)size
{
return _size;
}
- (id)initwithBrand:(NSString *)brand
size:(CGFloat)size
{
_brand = brand;
_size = size;
return self;
}
- (void)turn//转动
{
NSLog(@"轮胎转动");
}
@end
5.Engine.h
#import <Foundation/Foundation.h>
@interface Engine : NSObject
{
NSString * _brand;//品牌
CGFloat _power;//功率
CGFloat _displacement;//排量
}
- (BOOL)fire;
- (void)setBrand:(NSString *)brand;
- (NSString *)brand;
- (void)setPower:(CGFloat)power;
- (CGFloat)power;
- (void)setDisplacement:(CGFloat)displacement;
- (CGFloat)displacement;
- (id)initwithBrand:(NSString *)brand
power:(CGFloat)power
displacement:(CGFloat)displacement;
@end
6.Engine
#import "Engine.h"
@implementation Engine
- (BOOL)fire //返回的是一个BOOL值
{
unsigned long n = arc4random() % 11; //发动机行为的实现
if (n % 3 != 0) {
NSLog(@"点火成功");
return YES;
}
NSLog(@"点火失败");
return NO;
}
- (void)setBrand:(NSString *)brand
{
_brand = brand;
}
- (NSString *)brand
{
return _brand;
}
- (void)setPower:(CGFloat)power
{
_power = power;
}
- (CGFloat)power
{
return _power;
}
- (void)setDisplacement:(CGFloat)displacement
{
_displacement = displacement;
}
- (CGFloat)displacement
{
return _displacement;
}
- (id)initwithBrand:(NSString *)brand
power:(CGFloat)power
displacement:(CGFloat)displacement
{
_brand = brand;
_power = power;
_displacement = displacement;
return self;
}
@end
7.main.m
//创建一个引擎
Engine * engine = [[Engine alloc]initwithBrand:@"东风日产" power:130 displacement:1.8];
//创建一个轮胎
Tire * tire = [[Tire alloc]initwithBrand:@"米其林" size:100];
//创建一个车对象
Car * car = [[Car alloc]initwithBrand:@"奥迪A4" color:@"白色" price:300000];
//给汽车引擎类型的实例变量赋值(给车装上发动机)
[car setEngine:engine];
//装上轮胎
[car setTire:tire];
[car start];