对不同类型assgin，retain，和copy内部实现的方法

来源：互联网发布：软件项目经理资质证书编辑：程序博客网时间：2024/06/11 03:39

.h文件。。。。。。。

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@interface book : NSObject
/*{
    
    NSString *_bookName;    //书名
    CGFloat _bookThickness; //厚度
    NSString *_bookType;      //书类型
    NSInteger _bookPrice;     //书价格
    NSString *_publishingHouse;//出版社
    NSString *_publishintTime;  //出版时间
}*/  //在@property里面，其实就包含了定义实例变量，setter方法和getter方法。这里可以不用在定义实例变量了 
@property (nonatomic , copy)NSString *bookName;//用copy写完整的属性
@property (nonatomic , assign)CGFloat bookThickness;
@property (nonatomic , retain)NSString *bookType;//retain不建议使用，大多使用copy
@property (nonatomic , assign)NSInteger bookPrice;
@property (nonatomic , copy)NSString *publishingHouse;
@property (nonatomic , copy)NSString *publishintTime;
- (void)read;
- (void)write;
@end

.m文件

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@implementation book
@synthesize bookName = _bookName ;
@synthesize bookThickness = _bookThickness;
@synthesize bookType = _bookType;
@synthesize bookPrice = _bookPrice;
@synthesize publishingHouse = _publishingHouse;
@synthesize publishintTime = _publishintTime;
- (void)setBookName:(NSString *)bookName
{
    if(_bookName != bookName) {
        [_bookName release];//auto---All---Combined---Language--Objective C--->no这里是对内存的一个设置，
        _bookName = [bookName copy];
    }
}
- (NSString *)bookName
{
    return [[_bookName retain] autorelease];
}
- (void)setBookThickness:(CGFloat)bookThickness
{
    _bookThickness = bookThickness;
}
- (CGFloat)bookThickness
{
    return_bookThickness;
}
- (void)setBookType:(NSString *)bookType
{
    if(_bookType != bookType) {
        [_bookType release];
        _bookType = [bookType retain];//retain和copy唯一的不同在这里。
    }
}
- (NSString *)bookType
{
    return[[_bookType retain] autorelease];
}
- (void)setBookPrice:(NSInteger)bookPrice
{
    _bookPrice = bookPrice;
}
- (NSInteger)bookPrice
{
    return_bookPrice;
}
- (void)setPublishingHouse:(NSString *)publishingHouse
{
    if(_publishingHouse != publishingHouse) {
        [_publishingHouse release];
        _publishingHouse = [publishingHouse copy];
    }
}
- (NSString *)publishingHouse
{
    return[[_publishingHouse retain] autorelease];
}
- (void)setPublishintTime:(NSString *)publishintTime
{
    if(_publishintTime != publishintTime) {
        [_publishintTime release];
        _publishintTime = [publishintTime copy];
    }
}
- (NSString *)publishintTime
{
    return [[_publishintTime retain] autorelease];
}
- (void)read;
{
    NSLog(@"这是一本书");
}
- (void)write
{
    NSLog(@"可以写");
}
@end

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