NSObject-KVO

/** 监听对象属性变化  

@param keyPath 监听的属性
@param completeHandler 回调
*/
-(void)addObserverForKeyPath:(NSString *)keyPath complete:(CompleteHandler)completeHandler;  

/**
监听事件  

@param selector 事件方法字符串
@param funcHandler 回调
*/
-(void)addFuncObserverForSelector:(NSString *)selector withFuncHandler:(FuncHandler)funcHandler;  

/**
监听通知  

@param name 通知名
@param object obj
@param notificationHandler 回调
*/
-(void)addNotificationObserverForName:(NSString *)name object:(id)object withNotificationHandler:(NotificationHandler)notificationHandler;  

/**
监听UITextField、UITextView的text变化  

@param textHandler 回调
*/
-(void)addTextObserverWithTextHandler:(TextHandler)textHandler;