如何在中間件類中訪問 IHostingEnvironment

在 Asp.Net Core 中，如果創建了一個自定義中間件並將其放置在它自己的類中，如何IHostingEnvironment從中間件內部訪問？

例如，在我下面的課程中，我認為我可以注入IHostingEnvironment建構子，但它始終為空。關於如何訪問的任何其他想法IHostingEnvironment？

public class ForceHttps {
   private readonly RequestDelegate _next;
   private readonly IHostingEnvironment _env;

   /// <summary>
   /// This approach to getting access to IHostingEnvironment 
   /// doesn't work.  It's always null
   /// </summary>
   /// <param name="next"></param>
   /// <param name="env"></param>
   public ForceHttps(RequestDelegate next, IHostingEnvironment env) {
       _next = next;
   }


   public async Task Invoke(HttpContext context) {
       string sslPort = "";
       HttpRequest request = context.Request;


       if(_env.IsDevelopment()) {
           sslPort = ":44376";
       }

       if(request.IsHttps == false) {
           context.Response.Redirect("https://" + request.Host + sslPort + request.Path);
       }

       await _next.Invoke(context);

   }
}

方法注入有效，只需將其添加到方法簽名中

public async Task Invoke(HttpContext context, IHostingEnvironment env) {...}

引用自：https://stackoverflow.com/questions/41108099