如何在ObjectiveC中检查键值观察数组的字典? [英] How to check Key Value Observing in ObjectiveC for dictionary of arrays?

问题描述

我有以下代码:

 @property (strong, nonatomic) NSMutableDictionary *todoSessionDict;
    @synthesize todoSessionDict;

[self addObserver:self forKeyPath:@"todoSessionDict" options:NSKeyValueObservingOptionNew context:NULL];


-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {

}

------------------------
NSMutableArray *unCompletedTodosArr = [NSMutableArray  array];
NSMutableArray *completedTodosArr   = [NSMutableArray  array];

 [self.todoSessionDict setObject:unCompletedTodosArr forKey:@"unCompletedTodosArr"];
 [self.todoSessionDict setObject:completedTodosArr forKey:@"completedTodosArr"];

任何想法如何使用KVO检查self.todoSessionDict中的@"unCompletedTodosArr" and @"completedTodosArr"值是否已更改?

Any idea how to check if the @"unCompletedTodosArr" and @"completedTodosArr" values are changed in the self.todoSessionDict using KVO ?

推荐答案

首先，它应该是:

 [self addObserver:self forKeyPath:@"todoSessionDict.unCompletedTodosArr" options:0 context:nil];
  [self addObserver:self forKeyPath:@"todoSessionDict.completedTodosArr" options:0 context:nil];

对于这两种方法，

  #pragma mark - KVO
   -(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
   {
     // Here your actions depends on the key path...
    }

    -(void)didChangeValueForKey:(NSString *)key

     {

     }

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