如何在NSMutableArray中实现对象的键值观察

Question

我需要一些帮助来尝试在复杂的对象层次结构上理解KVO.让我设置一下场景.MyClass对象具有包含MyPerson对象的可变数组属性.我想观察MyClass的myPeople属性的变化.此外,我还想观察MyPerson对象中包含的所有属性.这是类定义.

@interface MyClass:NSObject
{
   NSMutableArray *myPeople;
}

@property(nonatomic, retain)NSMutableArray *myArray;

@end

这是MyPerson对象,

@interface MyPerson:NSObject
{
   NSString *myName;
   NSString *myLastName;
}

@property(nonatomic, retain)NSString *myName;
@property(nonatomic, retain)NSString *myLastName;

@end

以下列方式观察我感兴趣的属性是否正确？

MyClass *myClass = [[MyClass alloc] init]; //myPeople is filled with myPerson objects

MySchool *mySchool = [[MySchool alloc] init];

[myClass addObserver:mySchool
      forKeyPath:@"myPeople"
             options:NSKeyValueObservingOptionNew
         context:NULL];

[myClass addObserver:mySchool
      forKeyPath:@"myPeople.myName"
             options:NSKeyValueObservingOptionNew
         context:NULL]; //I am unsure about this one

[myClass addObserver:mySchool
      forKeyPath:@"myPeople.myLastName"
             options:NSKeyValueObservingOptionNew
         context:NULL]; //I am unsure about this one

Answer 1

不,这不对.您必须分别观察添加到阵列的任何对象的属性.因此,无论何时向数组添加对象或从数组中删除对象,都必须在添加/删除的对象中添加/删除观察者.