using ExcelDna.Integration; using ExcelDna.Registration; using System.Net.Http; namespace Rehau.Sku.Assist { public class AddIn : IExcelAddIn { public static HttpClient httpClient; public void AutoOpen() { RegisterFunctions(); httpClient = new HttpClient(); } public void AutoClose() { } void RegisterFunctions() { ExcelRegistration.GetExcelFunctions() .ProcessAsyncRegistrations(nativeAsyncIfAvailable: false) .RegisterFunctions(); } } }