Access appSettings in web.config from Thread in Class Library project

Question

Can I able to access appSettings section in my ASP.NET web.config file from a method in another referenced Class Library project when it is called as a new Thread? I'm accessing the setting through a property as

 private static string TempXmlFolder
 {
      get
      {
           return System.Web.HttpContext.Current.Server.MapPath(ConfigurationManager.AppSettings["ReceiptTempPath"] ?? "~/Receipts/TempXML");
      }
 }

There is an extension method for the matter to generate the receipt.

 internal static void GenerateReceipt(this IMatter matter)
 {
     try
     {
          string XmlFile = TempXmlFolder + "/Rec_" + matter.MatterID + ".xml";
          // ...
          // Generating receipt from the matter contents
          // ...
          // Saving generated receipt
     }
     catch (Exception ex)
     {
          ex.WriteLog();
     }
 }

I'm calling the receipt generation as a new thread from the class library like

 Thread printThread = new Thread(new ThreadStart(this.GenerateReceipt));
 // To avoid exception 'The calling thread must be STA, because many UI components require this' (Using WPF controls in receipt generation function)
 printThread.SetApartmentState(ApartmentState.STA);
 printThread.Start();
 // ...
 // Do another stuffs
 // ...
 // Wait to generate receipt to complete
 printThread.Join();

But since the HttpContext.Current is null inside the Thread, I'm not able to access the current web server configuration file.

Can you suggest there any way other than passing the current HttpContext to the Thread? If no, what are the things I've to take care to keep thread safety?

Edit #1

Currently I'm passing the HttpContext to the thread like

 System.Web.HttpContext currentContext = System.Web.HttpContext.Current;
 Thread printThread = new Thread(() => this.GenerateReceipt(currentContext));

and in the function,

 internal static void GenerateReceipt(this IMatter matter, System.Web.HttpContext htCont)
 {
      string TempXmlFolder = htCont.Server.MapPath(ConfigurationManager.AppSettings["ReceiptTempPath"] ?? "~/Receipts/TempXML");
      //...

Answer 1

Pass the TempXmlFolder into the thread. Don't rely on HttpContext.Current. Alternatively, pass the value of HttpContext.Current to the thread and calculate the value of TempXmlFolder later.

You can pass the value using any way you want. Maybe a field or a local variable that you capture with a lambda.