Objective-C 日记⑤ 内存管理、协议、Category 视频笔记

//内存管理第六课
#import <Foundation/Foundation.h>
#import "Person.h"
#import "Dog.h"

int main(int argc,const char *argv)
{    
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    
    Person *xiaoLi=[[Person alloc] init];
    //dog1 1
    Dog *dog1=[[[Dog alloc] init] autorelease];
    //把Dog1这条狗放在自动释放池里 上面的pool中
    //dog1 2
    xiaoLi.dog=dog1;
    
    
    //[dog1 release]; 有了autorelease 就不可以在release 
    //因为dog 已经放到pool中 在release 则dog1会清除
    [xiaoLi release]
    [pool release];//对拥有的非0（还存在）变量都release一次 
    
    return (0);
}


//dog.h
#import <Foundation/Foundation.h>
@interface Dog:NSObject
{
    int _ID;
}
@property int ID;
@end


//dog.m
#import<dog.h>
 @synthesize ID=_ID;

-(void) dealloc //对象减到0(对象销毁时)自动调用
{
    NSLog(@"dog  dealloc ");
}


//person.h
#import<Foundation/Foundation.h>
#import "Dog.h"
@interface Person:Object
{
    Dog *_dog;
}
@property (retain) Dog *dog;
@end


//person.m
＃import "Person.h"
@implementation Person
@Synthesize dog=_dog;
-(void) dealloc // 对象减到0时自动调用这条
{
    self.dog=nil;//对狗的计数器减1
    NSLog(@"person dealloc");
    [super dealloc];
}
@end

 

协议

//第七课：协议

int main(int argc,char *argv[])
{
    NSAutoreleasePool *pool =[[NSAutoreleasePool alloc] init];
}


//只有一个头文件 以Protocol开头  方法没有方法体 继匙自蠳SObject

@protocol MyProtocol <NSObject>

    -(void) init;
    -(int) updat:(int) time;
@end


//@optional  可以不实现 缺省 
//@required 必须凳迪帜 
//eg:
//@optional 可实现可不实现
//    -(void) init;
 
 //要实现的协议的名 用尖括号 多个用逗号隔开
 @interface:Foo:NSObject<MyProtocol,MouseListerner,MousKey>
 
 
 实现协议
 id<MyProtocol> test=[[MyTest alloc] init];
 
 
 if([test respondsToSelector:@select(showInfo)]){
    
 }
 
 
 
 
 
 
 //案例  
 
 
 
 //protocol
 @protocol MyProtocol<NSObject>
 @optional
-(void) print:(int) vlaue;//可选 
@required
-(int) printValue:(int)value1 andValue:(int)value2;
@end 

//MyTest.h
 @interface MyTest:NSObject<MyProtocol>
 -(void) showInfo;
 @end
 
 //MyTest.m
 -(void) ShowInfo
 {
    NSLog(@"Show info is calling");
 } 
 //来源于MyProtocol协议
 -(int) printValue:(int)value1 andValue:(int) value2
 {
    NSLog(@"print value1 and %d value2 %d",value1,value2);
    return 0;
 }
 -(void) print:(int)value
 {
    NSLog(@"print vlaue %d",value);
 }
 
 @end
 
 
 
#import <Foundation/Foundation.h>
# "MyTest.h"
# "MyProtocol.h"
int main(int argc,const char *argv[])
{
    @autorelease{
    
        MyTest *myTest=[[MyTest alloc] init];
        [myTest showInfo];
        //把print转化成SEL类型的方法 ＯＣ所有函数都可以转换成ＳＥＬ
        SEL sel=@selector(print:);// 有参数冒号注意
        if([myTest respondsToSelector:sel]){
            //判断myTest是否响应sel方法(print:)
            [myTest print:20];
        }
        [myTest pirntValue:10 andValue:290];
        [myTest release];
        
        //用协议
        id<MyProtocol> myProtocol =[[MyTest alloc] init];
        if([myProtocol respondsToSelector:@selector(print:)]){
            [myProtocol print:111];
        }
        [myProtocol printValue:193 andValue:103];
        [myProtocol release];
    }
    return 0;
} 

 

第八章：代理模式

　　

 

 

//Dod.h 文件
#import<Foundation/Foundation.h>
@protocol DogBark;// 协议前向声明
@class Dog;//@class 表示前向声明一个类
@interface Dog:NSObject
{
    NSTimer *timer;// 定时器
    int backCount;//叫的次数
    int _ID;
    
    id <DogBark> delegate;//任何类型 存储主人
    //告诉系统这个delegate是DogBark类型
}
@property int ID;

@property  (assign) id <DogBark> delegate;//指针赋值
@end


//方法二用协议来做
//定义一个人和狗通讯的方式protocol
@protocol DogBark<NSObject>
-(void) bark:(Dog *)thisDog count:(int)count;
@end



//Dod.m文件
#import "Dog.h"
@implementation Dog
@synthesize ID=_ID;
@synthesize delegate;
//构造函数ＩＤ 初始化
-(id) init
{
    self=[super init];
    if(self){
        timer=[NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:
        @selector(updateTimer:) userInfo:nil repeats:YES];
        //创建一个定时器 每隔1.0秒就调用[self updateTimer:nil]
    }
    return self;
}
-(void) updateTimer:(id) arg
{
    backCount++;
    NSLog(@"dog bark %d",backCount);
    //通知狗的主人
    [_dog setDelegate:self]; //把self传递到delegate中
    [delegate bark:self count:barkCount];
    //调用delegate里面的bark：count：方法
    //向主人汇报
}

@end

 


//Person.h
#import<Foundation/Foundation.h>
#import "Dog.h"
@interface Person:NSObject <DogBark> //实现协议
{
    DOg *_dog;
}

@property (retain) DOg *dog;
@end


//Person.m
#import "Person.h"
@implementation Person
@synthesize dog=_dog;

-(void) bark:(Dog *) thisDog count:(int)count
{
//当狗叫的时候来调用xiaoli人的这个方法
    NSLog(@"person this dog %d bark %d",[thisDog ID],count);
}

-(void) dealloc//当对象清零时 调用
{
    self.dog=nil;
    [super dealloc];
}

// 重写setDog 告知狗的主人是谁
-(void) setDog:(Dog *)dog
{
    if(_dog!=dog){
        [_dog release];
        _dog=[dog retain];
        //通知_dog的主人是self
    }
}

-(Dog *) dog
{
    return _dog;
}
@end




#import<Foundation/Foundation.h>
#import "Person.h"
#import "Dog.h"
int main(int argc,const char *argv[])
{
    @autoreleasepool{
        Person *xiaoLi=[[Person alloc] init];
        Dog *dog[[Dog alloc] int];
        [dog setID:10];
        
        [xiaoLi setDog:dog];
        
        [dog release];
        
        while(1){
            [[NSRunLoop currentRunLoop] run];
        }
        
        [xiaoLi release];
    }
    return 0;
}

 第九章：Category

　　

//Category 实际上是对类的扩展
//1实现继承之外的扩展方法机制(给一个类扩展动态的或者静态的一些方法进去) 
//不能完全替代继承（原因就是下面的缺点不能扩展字段和变量） 但可以完成继承不能完成的。写起来比继承稍微麻烦但比继承好用
//2可以做函数私有化
//eg:
//interface Foo(Private)//Private 可以不写
//-(void) test2;
//@end
//@implementation Foo
//-(void) test{
//    [self test2]
//}
//-(void) test2
//{
//    NSLog(@"test2")
//}
//@end


//缺点：类别Category只能扩展函数，消息，不能扩展字段，变量等

//命名规范
//一般Category命名为：
//    要扩展类名+扩展变量.[hm]
//比如：
//    NSString+ReverseString.h
//    NSString+ReverseString.m
//    
//    UIImageView+WebCache.h
//    UIImageView+WebCache.m
    
    
    
    

#import <Foundation/Foundation.h>
@implementation NSString (ReverseString)
-(id) reverseString
{
    NSUInteger len=[self length];
    //self 表示字符串本身
    NSMutableString *retStr=[NSMutableString stringWithCapacity:len];
    while(len>0){
        unichar c=[self characterAtIndex:--len];
        //从后去一个字符unichar
        NSLog(@"c is %C",c);//C国际字符
        NSString *s=[NSString stringWithFormat:@"%C",c];
        [retStr appendString:s]
    }
    return retStr;
}
@end

#import<Foundation/Foundation.h>
#import "NSString+ReverseString.h"

int main(int argc,const char *argv[])
{
    @autoreleasepool{
        NSString *string="Hello Word";
        NSString *retString=[string reverseString];
        NSLog(@"%@",retString);
    }
    return 0;
}