监听获取键盘高度

• (void)viewDidLoad
  {
  [super viewDidLoad];

  //增加监听，当键盘出现或改变时收出消息
  [[NSNotificationCenter defaultCenter] addObserver:self
  selector:@selector(keyboardWillShow:)
  name:UIKeyboardWillShowNotification
  object:nil];

  //增加监听，当键退出时收出消息
  [[NSNotificationCenter defaultCenter] addObserver:self
  selector:@selector(keyboardWillHide:)
  name:UIKeyboardWillHideNotification
  object:nil];

}

//当键盘出现或改变时调用

• (void)keyboardWillShow:(NSNotification )aNotification
  {
  //获取键盘的高度
  NSDictionary userInfo = [aNotification userInfo];
  NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
  CGRect keyboardRect = [aValue CGRectValue];
  int height = keyboardRect.size.height;
  }

//当键退出时调用

• (void)keyboardWillHide:(NSNotification *)aNotification
  {

}

能把这个原生代码 用native.js实现吗？