/// <summary>
/// 从索引移除一个元素
/// </summary>
/// <param name="element"></param>
protected void RemoveElement(IHtmlElement element)
{
ElementIndexes.ForAll(index => index.RemoveElement(element));
_elements.Remove(element);
}
/// <summary>
/// 索引内的元素移除一个属性
/// </summary>
/// <param name="element">被移除属性的元素</param>
/// <param name="attribute">移除的属性</param>
protected void RemoveAttribute(IHtmlElement element, IHtmlAttribute attribute)
{
ElementIndexes.ForAll(index => index.RemoveAttribute(element, attribute));
}
/// <summary>
/// 向索引添加一个元素
/// </summary>
/// <param name="element"></param>
protected void AddElement(IHtmlElement element)
{
ElementIndexes.ForAll(index => index.AddElement(element));
_elements.Add(element);
}