标记助手未在ASP.NET Core 2中处理

Question

我添加了以下标记帮助器:

using System;
using System.Linq;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.AspNetCore.Mvc.TagHelpers;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.AspNetCore.Razor.TagHelpers;

namespace X.TagHelpers
{
    [HtmlTargetElement(Attributes = ValidationForAttributeName + "," + ValidationErrorClassName)]
    public class ValidationClassTagHelper : TagHelper
    {
        private const string ValidationForAttributeName = "k-validation-for";
        private const string ValidationErrorClassName = "k-error-class";

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

        [HtmlAttributeName(ValidationErrorClassName)]
        public string ValidationErrorClass { get; set; }

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

        public override void Process(TagHelperContext context, TagHelperOutput output)
        {
            Console.WriteLine("\n\n------------!!!!!!---------\n\n");
            ModelStateEntry entry;
            ViewContext.ViewData.ModelState.TryGetValue(For.Name, out entry);
            if (entry == null || !entry.Errors.Any()) return;
            var tagBuilder = new TagBuilder(context.TagName);
            tagBuilder.AddCssClass(ValidationErrorClass);
            output.MergeAttributes(tagBuilder);
        }
    }
}

然后在_ViewImports.cshtml我添加了这一行:

@addTagHelper *, X.TagHelpers

该文件已正确编译,如果我引入语法错误dotnet build警告我.

然后在我的一个页面中添加:

<div k-validation-for="OldPassword" k-error-class="has-danger"></div>

如果我加载网页我看到在服务器端没有控制台输出和k-validation-for与k-error-class被转发到为是(相对于加入生成的页has-danger类的class属性).

我究竟做错了什么？

Answer 1

注册Tag Helpers时,它是必需的程序集,而不是命名空间 - 在文档中进行了解释.

...第二个参数"Microsoft.AspNetCore.Mvc.TagHelpers"指定包含Tag Helpers的程序集.Microsoft.AspNetCore.Mvc.TagHelpers是内置ASP.NET核心标记助手的程序集.

所以在你的情况下,你可以改变这个:

@addTagHelper *, X.TagHelpers

对此:

@addTagHelper *, X