转：objective-C 的OOP(下)-类（st…

先来定义一个Human父类

定义部分：

////  Human.h//  OOP////  Created by jimmy.yang on 11-2-9.//  Copyright 2011 __MyCompanyName__. All rights reserved.//#import <Foundation/Foundation.h>@interface Human : NSObject {        BOOL sex;}+(void) toString;-(void) showSex;@end

注：+(void)前的加号，就表示这一个是类方法(static方法)，而-(void)表示这是一个实例方法

实现部分：

注意：下面的 -(id) init 即为构造函数。对应的，还有一个-(void)dealloc方法用来释放资源（类似于析构函数或c#中的dispose()方法）-注：dealloc方法以后在内存管理中详细学习，这里先不管它。

////  Human.m//  OOP////  Created by jimmy.yang on 11-2-9.//  Copyright 2011 __MyCompanyName__. All rights reserved.//#import "Human.h"@implementation Human//构造函数-(id) init{        NSLog(@"init() in Human is called");        sex = TRUE;        return(self);}//static类方法+ (void)toString{        NSLog(@"this is a class method of Human");}//实例方法- (void)showSex{        NSLog(@"my sex is %@",sex?@"MALE":@"FEMALE");}@end

再来定义一个Woman子类

定义部分：

////  Woman.h//  OOP////  Created by jimmy.yang on 11-2-9.//  Copyright 2011 __MyCompanyName__. All rights reserved.//#import <Foundation/Foundation.h>#import "Human.h"@interface Woman : Human {        BOOL married;}-(void) canCook:(NSString*) foodName;-(void) setMarried:(BOOL)m;-(BOOL) Married;@end

实现部分：

注意下面的：setMarried与 Married 就是obj-C中属性的标准写法(当然以后还能看到其它简化的写法)

////  Woman.m//  OOP////  Created by jimmy.yang on 11-2-9.//  Copyright 2011 __MyCompanyName__. All rights reserved.//#import "Woman.h"@implementation Woman//Woman类的构造函数-(id) init{        NSLog(@"init() in Woman is called!");        if (self==[super init]){                sex = FALSE;                married = FALSE;        }        return (self);}//overwrite父类中的toString()+(void)toString{        NSLog(@"This is Woman's ToString()");}//Woman能做饭-(void)canCook:(NSString*) foodName{        NSLog(@"I can cook %@",foodName);}//属性的setter-(void) setMarried:(BOOL)m{        married = m;}//属性的getter-(BOOL) Married{        return married;}@end

main方法中的调用：

#import <Foundation/Foundation.h>#import "Human.h"#import "Woman.h"int main (int argc, const char * argv[]) {    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];    // insert code here...    NSLog(@"Hello, World!");                //调用类的“静态”方法        [Human toString];                NSLog(@"----------------");                //创造一个Human的实例        Human *man = [Human new];                //调用man的showSex方法        [man showSex];                NSLog(@"----------------");                //定义一个Woman子类的实例        Woman *wife = [Woman new];        [wife canCook:@"Rice"];                //调用继承自父类的方法        [wife showSex];                //设置属性        [wife setMarried:TRUE];                //读取属性值        NSLog(@"wife's married = %@",wife.Married==NO?@"FALSE":@"TRUE");                NSLog(@"----------------");                //调用overwrite后的toString方法        [Woman toString];                        //Factory模式中常用的手法，在这里依然适用(只不过编译时会有警告 'Human' may not respond to '-canCook:')        Human *wife2 = [Woman new];        [wife2 canCook:@"soap"];                                NSLog(@"----------------");            [pool drain];    return 0;}

 运行结果：

2011-02-09 17:01:02.016 OOP[1725:a0f] Hello, World!
2011-02-09 17:01:02.053 OOP[1725:a0f] this is a class method ofHuman
2011-02-09 17:01:02.062 OOP[1725:a0f] ----------------
2011-02-09 17:01:02.075 OOP[1725:a0f] init() in Human iscalled
2011-02-09 17:01:02.091 OOP[1725:a0f] my sex is MALE
2011-02-09 17:01:02.094 OOP[1725:a0f] ----------------
2011-02-09 17:01:02.099 OOP[1725:a0f] init() in Woman iscalled!
2011-02-09 17:01:02.104 OOP[1725:a0f] init() in Human iscalled
2011-02-09 17:01:02.105 OOP[1725:a0f] I can cook Rice
2011-02-09 17:01:02.108 OOP[1725:a0f] my sex is FEMALE
2011-02-09 17:01:02.109 OOP[1725:a0f] wife's married =TRUE
2011-02-09 17:01:02.111 OOP[1725:a0f] ----------------
2011-02-09 17:01:02.116 OOP[1725:a0f] This is Woman'sToString()
2011-02-09 17:01:02.120 OOP[1725:a0f] init() in Woman iscalled!
2011-02-09 17:01:02.121 OOP[1725:a0f] init() in Human iscalled
2011-02-09 17:01:02.123 OOP[1725:a0f] I can cook soap
2011-02-09 17:01:02.125 OOP[1725:a0f] ----------------