Question

使用RC1，您可以构建一个新的TagBuilder，并将其附加到自定义TagHelper的输出中：

public override void Process(TagHelperContext context, TagHelperOutput output)
{
   var indicator = new TagBuilder("span");
   indicator.AddCssClass("indicator");
   output.Content.Append(indicator);
}

现在，RC2失败，因为TagHelperOutput.Content.Append()只接受string。

我可以和TagBuilder.WriteTo()混淆，但与它的情况相比，这似乎过于复杂。

是否有新方法构建新标记并附加到我错过的输出中？

Answer 1

在RC2中，您可以使用

output.Content.AppendHtml(tag);

菜单标签助手示例：

视图：

<ul>
  <menu action="Index" controller="Home">Home page</menu>
  <menu action="List" controller="Home">List</menu>
</ul>

MenuTagHelper.cs：

[HtmlTargetElement(Attributes = "controller, action")]
public class MenuTagHelper : TagHelper
{
    public string Controller { get; set; }
    public string Action { get; set; }

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

    private readonly IUrlHelperFactory urlHelperFactory;

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

    public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
    {
        var sb = new StringBuilder();
        var urlHelper = urlHelperFactory.GetUrlHelper(ViewContext);
        var url = urlHelper.Action(Action, Controller);
        var text = (await output.GetChildContentAsync()).GetContent();

        output.TagName = "li";

        var a = new TagBuilder("a");
        a.MergeAttribute("href", $"{url}");
        a.MergeAttribute("title", text);
        a.InnerHtml.Append(text);

        var routeData = ViewContext.RouteData.Values;
        var currentController = routeData["controller"];
        var currentAction = routeData["action"];

        if (string.Equals(Action, currentAction as string, StringComparison.OrdinalIgnoreCase) && string.Equals(Controller, currentController as string, StringComparison.OrdinalIgnoreCase))
            output.Attributes.Add("class", "active");

        output.Content.AppendHtml(a);
    }
}

ASP.NET Core RC2 TagHelperOutput.Content.Append更改

1 个答案: