KVC

KVC （key value coding）键值编码

先定义两个类，person，dog

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

#import <Foundation/Foundation.h>
@class Dog;

@interface Person : NSObject
@property (nonatomic,copy) NSString *name;
@property (nonatomic,assign) int age;
@property (nonatomic,copy) NSString *phone;
@property (nonatomic,strong) Dog *dog;

@end

  //实例化两个person
        Person *p = [[Person alloc]init];
        Person *p1= [[Person alloc]init];
        //实例化dog
        Dog *d = [[Dog alloc] init];
        p.dog = d;
        
        NSArray *pArray = @[p,p1];
        

        // 1.给p.name赋值
        [p setValue:@"Tom" forKey:@"name"];
        
        // 2.用字典给p的属性赋值,类的属性必须在字典中key存在，可以比字典中得key多，但是不能少。
        [p setValuesForKeysWithDictionary:@{@"name":@"Jack",@"age":@10,@"phone":@"24234232"}];
        
        NSDictionary *dict = @{@"name":@"Cruise",@"age":@12,@"phone":@"123214wrew"};
        
        [p1 setValuesForKeysWithDictionary:dict];
        
       
        // 3.按照键值路径赋值
        [p setValue:@"fuck" forKeyPath:@"dog.dogName"];
        
        // 4.KVC按照键值路径取值时，如果对象不包含指定的键值，会自动进入对象内部，查找对象属性
        NSArray *a = [pArray valueForKeyPath:@"name"];
        
        NSLog(@"%@",a);
        
        NSLog(@"%@ ,name= %@,age = %d,phone = %@,dogname = %@",p,p.name,p.age,p.phone,p.dog.dogName);

输出结果：2014-05-25 19:49:26.634 xcode 小技巧- 自定义代码块[832:303] (
    Jack,
    Cruise
)
2014-05-25 19:49:26.641 xcode 小技巧- 自定义代码块[832:303] <Person: 0x100202d50> ,name= Jack,age = 10,phone = 24234232,dogname = fuck