如何从泛型类访问父类中的方法

我想这样做。

为了使用Fluent API创建一个自定义Html Helper，我创建了这个:

public interface IHelper:IHtmlString
{
    IHelper AddClass(string className);
    IHelper Attributes(object htmlAttributes);
}
public class Helper : IHelper
{
    private readonly Alert _parent;
    public Helper(Alert parent)
    {
        _parent = parent;
    }
    public string ToHtmlString()
    {
        return ToString();
    }
    public IHelper AddClass(string className)
    {
        return _parent.AddClass(className);
    }
    public IHelper Attributes(object htmlAttributes)
    {
        return _parent.Attributes(htmlAttributes);
    }
    public override string ToString()
    {
        return _parent.ToString();
    }
}

Alert类:

public interface IAlert : IHelper
{
    IHelper HideCloseButton(bool hideCloseButton);
    IHelper Success();
    IHelper Warning();
}
public class Alert : IAlert
{
    private readonly string _text;
    private AlertStyle _style;
    private  bool _hideCloseButton;
    private ICollection<string> _cssClass;
    private  object _htmlAttributes;
    public Alert(string text, AlertStyle style, bool hideCloseButton = false, object htmlAttributes = null)
    {
        _text = text;
        _style = style;
        _hideCloseButton = hideCloseButton;
        _htmlAttributes = htmlAttributes;
    }
    public override string ToString()
    {
        return "";
    }
    public string ToHtmlString()
    {
        return RenderAlert();
    }
    // private method RenderAlert() is omitted here.
    public IHelper AddClass(string className)
    {
        if (_cssClass == null) _cssClass = new List<string>();
        _cssClass.Add(className);
        return new Helper(this);
    }
    public IHelper Attributes(object htmlAttributes)
    {
        _htmlAttributes = htmlAttributes;
        return new Helper(this);
    }
    public IHelper HideCloseButton(bool hideCloseButton)
    {
        _hideCloseButton = hideCloseButton;
        return new Helper(this);
    }
    public IHelper Success()
    {
        _style = AlertStyle.Success;
        return new Helper(this);
    }
    public IHelper Warning()
    {
        _style = AlertStyle.Warning;
        return new Helper(this);
    }
}

问题是我的Helper类的构造函数直接访问Alert。然后很难将我的IHelper和Helper更改为通用的IHelper<T>和Helper<T>，以用于我的其他自定义助手，如DropDownList和CheckBoxGroup。

因为AddClass和Attributes方法应该对所有其他Html助手可用，我绝对不想有重复的代码。但是写这个泛型类的正确方法是什么呢?