OC內存管理Demo

//主函數

#import <Foundation/Foundation.h>

#import "Car.h"

int main(int argc, const char * argv[]) {

    Lamp *lamp = [[Lamp alloc] init];                                     //初始化車燈對象

    lamp.wattage = 75;

    Engine *engine = [[Engine alloc] initWithModel:@"MX-8" Capacity:180]; //初始化引擎對象

    Car *benz = [[Car alloc] initWithName:@"奔馳" Licence:@"京A:DB250"];  //初始化汽車對象

    benz.engine = engine;

    [engine release];           //將engine對象賦給benz后，引用計數-1，還剩1

    benz.lamp = lamp;

    [lamp release];             //將lamp對象賦給benz后，引用計數-1，還剩1

    [benz run];                                 //調用run方法

    //為上述方法設置定時器

//    [NSTimer scheduledTimerWithTimeInterval:1

//                                     target:benz

//                                   selector:@selector(run)

//                                   userInfo:nil

//                                    repeats:YES];

//    NSLog(@"-------------分割線--------------");

    [benz stop];                                //調用stop方法

    //為上述方法設置定時器

//    [NSTimer scheduledTimerWithTimeInterval:1

//                                     target:benz

//                                   selector:@selector(stop)

//                                   userInfo:nil

//                                    repeats:YES];

//    NSLog(@"-------------分割線--------------");

    [benz release];//benz對象使用完畢，釋放內存，此時benz、engine、lamp引用計數全部為0，系統自動調用dealloc方法銷毀內存

    //RunLoop10秒后停止

//    [[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:10]];

    return 0;

}

Car類：

//car.h

#import <Foundation/Foundation.h>

#import "Engine.h"

#import "Lamp.h"

@interface Car : NSObject

{

    NSString *_name;        //名字

    NSString *_licence;     //車牌號

    Engine *_engine;        //引擎對象

    Lamp *_lamp;            //車燈對象

}

//對4個實例變量使用@property生成set和get方法

@property (nonatomic, copy) NSString *name;

@property (nonatomic, copy) NSString *licence;

@property (nonatomic, retain)Engine *engine;

@property (nonatomic, retain)Lamp *lamp;

//自定義初始化方法

- (id)initWithName:(NSString *)name Licence:(NSString *)licence;

//啟動 方法

- (void)run;

//停止 方法

- (void)stop;

- (void)dealloc;

@end

//Car.m

#import "Car.h"

@implementation Car

- (id)initWithName:(NSString *)name Licence:(NSString *)licence

{

    self = [super init];

    if (self) {

        _name = name;

        _licence = licence;

    }

    return self;

}

- (void)run

{

    NSLog(@"車牌號為：%@的%@車 啟動了", _licence,  _name);

    [_lamp light];

    [_engine turn];

    NSLog(@"-------------分割線--------------");

}

- (void)stop

{

    [_lamp dark];

    [_engine stopTurn];

    NSLog(@"車牌號為：%@的%@車 停止了", _licence,  _name);

    NSLog(@"-------------分割線--------------");

}

- (void)dealloc

{

    [_lamp release];

    _lamp = nil;

    [_engine release];

    _engine = nil;

    NSLog(@"車牌號為：%@的%@車 卒！", _licence,  _name);

    [super dealloc];

    self = nil;

}

@end

Engine類：

//Engine.h

#import <Foundation/Foundation.h>

@interface Engine : NSObject

{

    NSString *_model;       //型號

    NSInteger _capacity;    //排量

}

@property (nonatomic, copy) NSString *model;

@property (nonatomic, assign) NSInteger capacity;

//自定義初始化方法

- (id)initWithModel:(NSString *)model Capacity:(NSInteger)capacity;

//轉動 方法

- (void)turn;

//停止轉動 方法

- (void)stopTurn;

- (void)dealloc;

@end

//Engine.m

#import "Engine.h"

@implementation Engine

- (id)initWithModel:(NSString *)model Capacity:(NSInteger)capacity

{

    self = [super init];

    if (self) {

        _model = model;

        _capacity = capacity;

    }

    return self;

}

- (void)turn

{

    NSLog(@"型號為%@，排量為%ld的引擎 轉動了", _model, _capacity);

}

- (void)stopTurn

{

    NSLog(@"型號為%@，排量為%ld的引擎 停止轉動了", _model, _capacity);

}

- (void)dealloc

{

    NSLog(@"型號為%@，排量為%ld的引擎 卒！", _model, _capacity);

    [super dealloc];

}

@end

Lamp類：

//Lamp.h

#import <Foundation/Foundation.h>

@interface Lamp : NSObject

{

    int _wattage;

}

@property (nonatomic, assign) int wattage;

//燈亮 方法

- (void)light;

//燈滅 方法

- (void)dark;

- (void)dealloc;

@end

//Lamp.m

#import "Lamp.h"

@implementation Lamp

//燈亮 方法

- (void)light

{

    NSLog(@"瓦數為%d的燈亮了", _wattage);

}

//燈滅 方法

- (void)dark

{

    NSLog(@"瓦數為%d的燈滅了", _wattage);

}

- (void)dealloc

{

    NSLog(@"瓦數為%d的燈 卒！", _wattage);

    [super dealloc];

}

@end