KVC

KVC
    概念:Key Value Coding
    作用:
        1.KVC可以给对象的私有变量赋值(UIPageControl)
        2.用于字典转模型(MJExtension)
        3.通过KVC取出私有变量的值
        4.模型对象转字典(了解)
    
    使用注意:
        1.设置key/keyPath位置的字符串必须保证有对应的属性(或者_属性)
        2.字典转模型的使用注意:
            1> 必须保证字典中对应key在模型中能找到对应的属性
            2> 模型中的属性可以在字典中没有对应的Key
 
    setValue:forKey:和setValue:forKeyPath区别
        keyPath可以根据内部点语法,进一步查找对应的key

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        
        /*
        // 1.创建Person对象
        Person *p = [[Person alloc] init];
        p.book = [[Book alloc] init];
        
        [p setValue:@"18" forKey:@"age"];
        [p setValue:@"20" forKeyPath:@"age"];
        
        // [p.book setValue:@"100" forKey:@"price"];
        // [p.book setValue:@"200" forKeyPath:@"price"];
        
        // [p setValue:@"300" forKey:@"book.price"];
        [p setValue:@"300" forKeyPath:@"book.price"];
        */
        
        // MJExtension
        NSDictionary *dict = @{
                               @"name" : @"why",
                               @"height" : @"1.89",
                               @"age" : @"18",
                               @"weight" : @"60",
                               @"book" : @{@"price" : @"200"}
                               };
        
        Person *p = [Person personWithDict:dict];
        
        NSLog(@"%@", p.book);
    }
    return 0;
}

void notice()
{
    // 1.注意一
    /*
     // 1.创建Person对象
     Person *p = [[Person alloc] init];
     
     // 2.给p对象的属性赋值
     // [p setValue:@"20" forKeyPath:@"aga"];
     */
    
    // 2.注意二
    NSDictionary *dict = @{
                           @"name" : @"why",
                           @"height" : @"1.89",
                           @"age" : @"18",
                           @"weight" : @"60"
                           };
    Person *p = [Person personWithDict:dict];
    
    NSLog(@"age:%ld", p.age);
}

void getValue()
{
    // 1.创建Person对象
    Person *p = [[Person alloc] init];
    
    // 2.给属性赋值
    p.name = @"xiaobai";
    p.age = 1;
    
    // NSLog(@"name:%@ age:%ld height:%@", p.name, p.age, [p valueForKeyPath:@"height"]);
    /*
     NSMutableDictionary *dict = [NSMutableDictionary dictionary];
     [dict setObject:p.name forKey:@"name"];
     */
    NSDictionary *dict = [p dictionaryWithValuesForKeys:@[@"name", @"age", @"height"]];
    NSLog(@"%@", dict);
    
    // NSArray<NSString *> *array = nil;
    // NSDictionary<NSString *, id> 泛型
}

void setValue()
{
    /*
     // 1.创建Person对象
     Person *p = [[Person alloc] init];
     
     // 2.给p属性赋值
     // p.name = @"why";
     [p setValue:@"lmj" forKey:@"name"];
     // [p setValue:@"1.88" forKey:@"_height"];
     [p setValue:@"1.88" forKeyPath:@"height"];
     
     NSDictionary *dict = @{
     @"name" : @"why",
     @"height" : @"1.89",
     @"age" : @"18"
     };
     p.name = dict[@"name"];
     [p setValue:dict[@"height"] forKeyPath:@"height"];
     p.age = [dict[@"age"] integerValue];
     */
    // 1.定义字典
    NSDictionary *dict = @{
                           @"name" : @"why",
                           @"height" : @"1.89",
                           @"age" : @"18"
                           };
    
    // 2.字典转模型
    Person *p = [Person personWithDict:dict];
    
    NSLog(@"%@", p);
}