mvc 获取 HtmlHelper 表达式值

public static MvcHtmlString Try<TModel, TProperty>(
    this HtmlHelper<TModel> htmlHelper, 
    Expression<Func<TModel, TProperty>> expression
)
{
    var builder = new TagBuilder("textarea");
    builder.AddCssClass("ckeditor");
    builder.MergeAttribute("cols", "80");
    builder.MergeAttribute("name", "editor1");
    builder.MergeAttribute("id", expression.Name); // not sure about the id - verify
    var value = ModelMetadata.FromLambdaExpression(
        expression, htmlHelper.ViewData
    ).Model;
    builder.SetInnerText(value.ToString());
    return MvcHtmlString.Create(builder.ToString());
}