cannot convert from System.Collections.Generic.List<sales.ScanInfo> to System.Collections.Generic.IEnumerable<System.Threading.Tasks.Task>

Question

I have the following code inside my c# console application, where i am calling a method called getInfo in parallel using WhenAll() method, as follow:-

class Program
    {
        static int concurrentrequests = int.Parse(ConfigurationManager.AppSettings["ConcurrentRequests"]);
        static SemaphoreSlim throttler = new SemaphoreSlim(initialCount: concurrentrequests);

        private static ScanInfo getInfo(string website)
        {
            throttler.Wait();
            ScanInfo si = new ScanInfo();
            int counter = 1;
            try
            {
              //code goes here..

            }
            catch (Exception e)
            {
              //code goes here
            }

            finally
            {

             throttler.Release();
            }

            }
            return si;
        }

        static void Main(string[] args)
        {
            Marketing ipfd = new Marketing();
            try
            {
                using (WebClient wc = new WebClient()) // call the PM API to get the account id 
                {
                   //code goes here
                }
            }
            catch (Exception e)
            {


            }
            var tasks = ipfd.companies.Select(c => getInfo(c.properties.website.value)).ToList();
            var results = Task.WhenAll(tasks);

           //code goes here..   
        }       
    }

but i am getting this exception:-

Argument 1: cannot convert from
System.Collections.Generic.List<Sales.ScanInfo> to
System.Collections.Generic.IEnumerable<System.Threading.Tasks.Task>

so can anyone advice why i am getting this error?

Answer 1

  var tasks = ipfd.companies.Select(c => getInfo(c.properties.website.value)).ToList();
  var results = Task.WhenAll(tasks);

tasks contains the results. YOu dont have to do any waiting at all. What make syou think you do. So just do

  var results  = ipfd.companies.Select(c => getInfo(c.properties.website.value)).ToList();