Question

在ASP.Net Core 2.0中为条件类标记助手实现existing question的解决方案时，我没有得到预期的结果。

标记助手是已发布答案的直接副本，尚未修改。

按照示例而不是类名称，我将获得完整的属性名称以及指定的类。

我做错了什么？

TagHelper

using Microsoft.AspNetCore.Razor.TagHelpers;
using System;
using System.Collections.Generic;
using System.Linq;

namespace PerformanceTools.TagHelpers
{
    [HtmlTargetElement("div", Attributes = ClassPrefix + "*")]
    public class ConditionClassTagHelper : TagHelper
    {
        private const string ClassPrefix = "condition-class-";

        [HtmlAttributeName("class")]
        public string CssClass { get; set; }

        private IDictionary<string, bool> _classValues;

        [HtmlAttributeName("", DictionaryAttributePrefix = ClassPrefix)]
        public IDictionary<string, bool> ClassValues
        {
            get
            {
                return _classValues ?? (_classValues = new Dictionary<string, bool>(StringComparer.OrdinalIgnoreCase));
            }
            set
            {
                _classValues = value;
            }
        }

        public override void Process(TagHelperContext context, TagHelperOutput output)
        {
            var items = _classValues.Where(e => e.Value).Select(e => e.Key).ToList();

            if (!string.IsNullOrEmpty(CssClass))
            {
                items.Insert(0, CssClass);
            }

            if (items.Any())
            {
                var classes = string.Join(" ", items.ToArray());

                output.Attributes.Add("class", classes);
            }
        }
    }
}

控制器

public IActionResult ConditionalTest()
{
    List<ConditionalTestViewModel> model = new List<ConditionalTestViewModel>();
    model.Add(new ConditionalTestViewModel { Active = true });
    model.Add(new ConditionalTestViewModel { Active = false });
    return View("ConditionalTest", model);
}

模型

public class ConditionalTestViewModel
{
    public bool Active { get; set; }
}

查看

@model IEnumerable<ConditionalTestViewModel>

<div>Conditional Test</div>
@foreach(var c in Model)
{
    <div condition-class-active="@c.Active">@c.Active</div>
}

输出

<div id="container-body" class="container">

<div>Conditional Test</div>
    <div condition-class-active="conditional-class-active">True</div>
    <div>False</div>
</div>

更新：正如指出TagHelper condition-class-*而非conditional-class-*，我已用此更新了我的问题，但问题仍然存在。

Answer 1

根据您提到的question，您有拼写错误。您应该使用condition-class-active而不是conditional-class-active，如下所示：

<div>Conditional Test</div>
@foreach(var c in Model)
{
    <div condition-class-active="@c.Active">@c.Active</div>
}

_ViewImports.cshtml中的

添加对taghelper的引用，如下所示

@addTagHelper "*, WebApplication3"

ASP.Net核心条件类标记助手

1 个答案: