c# - 如何解析来自 TagHelper 的 ~ 根链接

Question

在 ASP.NET 5 MVC6 RC1 中——我有一个 ViewComponent，它旨在代表我传统的“屏幕左侧”主菜单。

我正在编写我的第一个 TagHelper 来表示每个菜单项链接。

我卡在了尝试创建超链接的部分。

如何解决 ~/dashboard/summary?

如果我在此页面上显示菜单，链接显示为 /dashboard/~/dashboard/summary。

@Url.Content("...") 显示 @Url.Content("...") 即不作为 Razor 处理。标签助手输出纯。

理想情况下，我希望解决方案与 .NET Core 兼容，因为我最终的目标是 .NET Core 可部署解决方案。

见下文:

namespace Website
{

    /// <summary>
    /// <MainMenuLink area="" controller="" action=""></MainMenuLink>
    /// 
    /// to render
    /// 
    ///  <a href="~/account/manage/ChangePassword" class="list-group-item @GetClassName("manage", "changepassword")">
    ///    <p class="list-group-item-text"><i class="fa fa-terminal"></i>&nbsp;&nbsp;Change my password</p>
    /// </a>
    /// 
    /// 
    /// </summary>
    [HtmlTargetElement(Attributes = "area, controller, action")]
    public class MainMenuLinkTagHelper : TagHelper
    {
        [HtmlAttributeName("area")]
        public string Area { get; set; }

        [HtmlAttributeName("controller")]
        public string Controller { get; set; }

        [HtmlAttributeName("action")]
        public string Action { get; set; }

        public UrlHelper urlHelper { get; set; }

        public override void Process(TagHelperContext context, TagHelperOutput output)
        {
            output.TagName = "a";    // Works    
            // Stuck here - I want ~/ to resolve to the base root.  
            // At the moment the address is here is localhost:XXXXX/dashboard/~/dashboard/summary

            // Would prefer to use a method which can be used with .net core and not System.Web

            output.Attributes.Add("href", "~/dashboard/summary");
            output.Content.SetHtmlContent("Click me");

        }        
        /// <summary>            
    }
}

谢谢!丹.

Answer 1

ASP Core 2.0 默认情况下似乎没有在 IServiceCollection 中包含 IActionContextAccessor，因此您需要在启动时注册它以接受工作解决方案:

services.AddSingleton<IActionContextAccessor, ActionContextAccessor>();

否则，提供的属性可以将 TagHelper 的属性设置为扩展 ActionContext 的 ViewContext

using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.AspNetCore.Mvc.Routing;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.AspNetCore.Razor.TagHelpers;

[HtmlTargetElement("my-tag")]
public class MyTagHelper : TagHelper {

    private readonly IUrlHelperFactory urlHelperFactory;

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

    public MyTagHelper (IUrlHelperFactory urlHelperFactory) {
        this.urlHelperFactory = urlHelperFactory;
    }

    public override void Process(TagHelperContext context, TagHelperOutput output) {
        var urlHelper = urlHelperFactory.GetUrlHelper(ViewContext);
    }
}

注意:ViewContext 属性必须有一个公共(public)设置方法