对象属性操作－包含kvc---ios

#import <Foundation/Foundation.h>
@class Author;
@interface Books : NSObject{

 @private
    NSString *color;
    int book_id;
    NSString *box;
    Author *author;
    NSArray *relationbook;
    float price;

@public
    NSString *name;

}

@property (nonatomic) int size;

-(void) setBox:(NSString *) box;
-(NSString *) box;

-(NSString *) method;
@end

#import "Books.h"

@implementation Books

@synthesize  size=_size;

-(void) setBox:(NSString *) _box{
    box=_box;
}

-(NSString *) box{
    return box;
}

-(NSString *) method{
    return @"这个方法可以通过［］，或者点语法调用";
}
@end

#import <Foundation/Foundation.h>

@interface Author : NSObject
@property (nonatomic,copy) NSString *name;

@end

#import "Author.h"

@implementation Author
@synthesize name=_name;
@end

        Books *book=[[Books alloc] init];

        //当属性为public时，可以通过指针来操作,kvo,kvc操作
        book->name=@"iso开发";
        NSLog(@"%@",book->name);
        [book setValue:@"iphone" forKeyPath:@"name"];
        NSLog(@"%@",[book valueForKey:@"name"]);

        //当属性为private时,可以用property和synthesize来自动生成get,set方法，然后通过点语法或者调用自动生成方法来操作
        book.size=12;
        NSLog(@"%d",book.size);
        [book setSize:14];//自动生成的set方法
        NSLog(@"%d",[book size]);//自动生成的get方法
        [book setValue:[NSNumber numberWithInt:2323] forKeyPath:@"size"];
        NSLog(@"%@",[book valueForKey:@"size"]);

        //当属性为private时，可以手动生成，然后通过点语法或者调用方法来操作
        NSString *content=@"书的内容";
        book.box=content;
        NSLog(@"%@",book.box);
        [book setBox:content];
         NSLog(@"%@",[book box]);
        [book setValue:@"来说" forKeyPath:@"box"];
        NSLog(@"%@",[book valueForKey:@"box"]);

        //声明普通方法可以通过点语法调用或者［］调用
        NSLog(@"%@",[book method]);
        NSLog(@"%@",book.method);

        //当属性为private时，可以通过kvo,kvc,即下面方式访问
        //-----属性为普通类型操作
        [book setValue:@"android开发" forKey:@"name"];
        [book setValue:@"whilte" forKey:@"color"];
        NSLog(@"%@:%@",[book valueForKey:@"name"],[book valueForKey:@"color"]);

        //－－－－属性为自定义对象操作1－－对象
        Author *author=[[Author alloc] init];
        author.name=@"caicai";
        [book setValue:author forKey:@"author"];
        Author *author2=[book valueForKey:@"author"];
        NSLog(@"%@",author2.name);

        //－－－－属性为自定义对象操作2－－对象－－路径访问
        [book setValue:@"caitou" forKeyPath:@"author.name"];
        NSLog(@"%@",[book valueForKeyPath:@"author.name"]);

        //－－－－属性为自定义对象操作2－－对象数组－－路径访问
        NSMutableArray *relationBook=[NSMutableArray arrayWithCapacity:3];
        for (int i=0; i<3; i++) {
            Books *book=[[Books alloc] init];
            NSString *name=[NSString stringWithFormat:@"job_%d",i];
            [book setValue:name forKeyPath:@"name"];
            [book setValue:@(12+i) forKeyPath:@"price"];
            [relationBook addObject:book];
        }
        [book setValue:relationBook forKeyPath:@"relationbook"];
        NSArray *names=[book valueForKeyPath:@"relationbook.name"];
        NSLog(@"%@",names);
        //kvc简单运算 sum max avg count
         NSLog(@"%@",[book valueForKeyPath:@"relationbook.@sum.price"]);
         NSLog(@"%@",[book valueForKeyPath:@"relationbook.@count"]);
        NSLog(@"%@",[book valueForKeyPath:@"relationbook.@max.price"]);
        NSLog(@"%@",[book valueForKeyPath:@"relationbook.@avg.price"]);