在只读输入字段中呈现特殊字符

Question

在ASP.NET MVC应用程序中，我使用TagBuilder创建只读输入字段。

public class DisplayTextFieldBuilder<TModel, TProperty>
{
    private HtmlHelper<TModel> _helper;
    private Expression<Func<TModel, TProperty>> _expression;

    public DisplayTextFieldBuilder(HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression)
    {
        _helper = helper;
        _expression = expression;            
    }

    public override string ToString()
    {        

        var id = _helper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(ExpressionHelper.GetExpressionText(_expression));
        var name = _helper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(ExpressionHelper.GetExpressionText(_expression));

        var value = HttpUtility.HtmlEncode(_helper.DisplayFor(_expression).ToString());         

        TagBuilder builder = new TagBuilder("input");
        builder.MergeAttribute("value", value);
        builder.MergeAttribute("id", id);
        builder.MergeAttribute("name", name);            
        builder.MergeAttribute("readonly", "readonly");                        

        var html = builder.ToString(TagRenderMode.SelfClosing);            

        return html;
    }

但是某些字符串无法正确呈现。例如，假设模型属性值为 Foe`s BBQ （注意它有撇号）
然后

HttpUtility.HtmlEncode(_helper.DisplayFor(_expression).ToString())

将此值呈现为Foe's, BBQ

如果我删除html编码，那么

 _helper.DisplayFor(_expression).ToString()

将此值呈现为Foe's, BBQ

我缺少什么？