ASP.NET-Core嵌套的ASP TagHelper

根据你的描述，我建议你可以使用IHtmlGenerator生成label asp-for，input asp-for，asp-validation-fortaghelper的代码。

更多详细信息，您可以参考以下代码：

标签助手：

using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.AspNetCore.Razor.TagHelpers;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;

namespace SecurityRelatedIssue
{
    [HtmlTargetElement("input-helper")]
    public class inputhelper : TagHelper
    {
        [HtmlAttributeName("asp-for")]
        public ModelExpression For { get; set; }

        private readonly IHtmlGenerator _generator;

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

        public inputhelper(IHtmlGenerator generator)
        {
            _generator = generator;
        }

        public override void Process(TagHelperContext context, TagHelperOutput output)
        {
            using (var writer = new StringWriter())
            {
                writer.Write(@"<div class=""form-group"">");

                var label = _generator.GenerateLabel(
                                ViewContext,
                                For.ModelExplorer,
                                For.Name, null,
                                new { @class = "control-label" });

                label.WriteTo(writer, NullHtmlEncoder.Default);

                var textArea = _generator.GenerateTextBox(ViewContext,
                                    For.ModelExplorer,
                                    For.Name,
                                    For.Model,
                                    null,
                                    new { @class = "form-control" });

                textArea.WriteTo(writer, NullHtmlEncoder.Default);

                var validationMsg = _generator.GenerateValidationMessage(
                                        ViewContext,
                                        For.ModelExplorer,
                                        For.Name,
                                        null,
                                        ViewContext.ValidationMessageElement,
                                        new { @class = "text-danger" });

                validationMsg.WriteTo(writer, NullHtmlEncoder.Default);

                writer.Write(@"</div>");

                output.Content.SetHtmlContent(writer.ToString());

            }

        }
    }
}

在中注册标签助手 _ViewImports.cshtml

@addTagHelper *,{yourapplicationnamespace}

用法：

<input-helper asp-for="@Model.str" ></input-helper>

结果：