KVO的使用(键值监听)

Key-Value Observing  键值监听。

      stockForKVO = [[StockData alloc] init];
          [stockForKVO setValue:@"searph" forKey:@"stockName"];
          [stockForKVO setValue:@"10.0" forKey:@"price"];
          [stockForKVO addObserver:self forKeyPath:@"price" options:NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld context:NULL];
  
 

      -(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
      {
         if([keyPath isEqualToString:@"price"])
          {
              myLabel.text = [stockForKVO valueForKey:@"price"];
          }
      }
  
 

      - (void)dealloc
      {
          [super dealloc];
          [stockForKVO removeObserver:self forKeyPath:@"price"];
          [stockForKVO release];
      }
  
 

文章来源: zzzili.blog.csdn.net，作者：清雨小竹，版权归原作者所有，如需转载，请联系作者。

原文链接：zzzili.blog.csdn.net/article/details/38895197