[HtmlTargetElement("editor", Attributes = ForAttributeName, TagStructure = TagStructure.WithoutEndTag)]
    public class EditorTagHelper : TagHelper {
        private const string ForAttributeName = "asp-for";
        private const string DisabledAttributeName = "asp-disabled";
        private const string RequiredAttributeName = "asp-required";
        private const string RenderFormControlClassAttributeName = "asp-render-form-control-class";
        private const string TemplateAttributeName = "asp-template";
        private const string PostfixAttributeName = "asp-postfix";

        private readonly IHtmlHelper _htmlHelper;

        [HtmlAttributeName(ForAttributeName)]
        public ModelExpression For { get; set; }

        [HtmlAttributeName(DisabledAttributeName)]
        public string IsDisabled { set; get; }

        [HtmlAttributeName(RequiredAttributeName)]
        public string IsRequired { set; get; }

        [HtmlAttributeName(RenderFormControlClassAttributeName)]
        public string RenderFormControlClass { set; get; }

        [HtmlAttributeName(TemplateAttributeName)]
        public string Template { set; get; }

        [HtmlAttributeName(PostfixAttributeName)]
        public string Postfix { set; get; }

        [HtmlAttributeNotBound]
        [ViewContext]
        public ViewContext ViewContext { get; set; }

        public EditorTagHelper(IHtmlHelper htmlHelper) {
            _htmlHelper = htmlHelper;
        }

        public override void Process(TagHelperContext context, TagHelperOutput output) {
            if (context == null) {
                throw new ArgumentNullException(nameof(context));
            }

            if (output == null) {
                throw new ArgumentNullException(nameof(output));
            }

            output.SuppressOutput();

            var htmlAttributes = new Dictionary<string, object>();

            bool.TryParse(IsDisabled, out var disabled);
            if (disabled) {
                htmlAttributes.Add("disabled", "disabled");
            }

            bool.TryParse(IsRequired, out var required);
            if (required) {
                output.PreElement.SetHtmlContent("<div class=\"input-group input-group-required\">");
                output.PostElement.SetHtmlContent("<div class=\"input-group-btn\"><span class=\"required\">*</span></div></div>");
            }

            var viewContextAware = _htmlHelper as IViewContextAware;
            viewContextAware?.Contextualize(ViewContext);

            bool.TryParse(RenderFormControlClass, out var renderFormControlClass);
            if (string.IsNullOrEmpty(RenderFormControlClass) && For.Metadata.ModelType.Name.Equals("String") || renderFormControlClass)
                htmlAttributes.Add("class", "form-control");

            if (For.Metadata.AdditionalValues.TryGetValue("PlaceHolderAttribute", out var value)) {
                if (value is PlaceHolderAttribute placeholder) {
                    var content = placeholder.Content;
                    htmlAttributes.Add("placeholder", content);
                }
            }

            var viewEngine = CommonHelper.GetPrivateFieldValue(_htmlHelper, "_viewEngine") as IViewEngine;
            var bufferScope = CommonHelper.GetPrivateFieldValue(_htmlHelper, "_bufferScope") as IViewBufferScope;

            var templateBuilder = new TemplateBuilder(
                viewEngine,
                bufferScope,
                _htmlHelper.ViewContext,
                _htmlHelper.ViewData,
                For.ModelExplorer,
                For.Name,
                Template,
                readOnly: false,
                additionalViewData: new { htmlAttributes, postfix = this.Postfix });

            var htmlOutput = templateBuilder.Build();
            output.Content.SetHtmlContent(htmlOutput.RenderHtmlContent());
        }
    }

public class SampleModel {
        [Display(Name = "标题")]
        [PlaceHolder("请提供标题")]
        [Required(ErrorMessage = "请输入主题")]
        [MaxLength(100,ErrorMessage = "太多字了")]
        public string Name { get; set; }

        [Display(Name = "标题")]
        [PlaceHolder("请提供标题")]
        [Required(ErrorMessage = "请输入主题")]
        [MaxLength(100, ErrorMessage = "太多字了")]
        public string Title { get; set; }
    }

@model SampleModel
<editor asp-for="Name" asp-required="true" />
<editor asp-for="Title" asp-required="true" />