public async Task <ViewResult> Asynchronous() { //Asynchronous methods long?traditionalLength = await MyAsyncMethods.TraditionalGetPageLength(); long?simplyLength = await MyAsyncMethods.SimplifyGetPageLength(); Console.WriteLine($"traditionalLength:{traditionalLength}, simplyLength:{simplyLength}"); //Asynchronous Enumerable List <String> output = new List <string>(); await foreach (long?length in MyAsyncMethods.GetPageLength(output, "apress.com", "microsoft.com", "amazon.com")) { output.Add($"Page length : {length}"); } foreach (string item in output) { Console.WriteLine(item); } return(View(new string[] { $"traditionalLength:{traditionalLength}, simplyLength:{simplyLength}" })); }