C# Task Return Value

Question

I'am making an application in C# .Net 4.5. I am trying to use multithreading, via tasks. I have an array of tasks that I get to run some process. I want the task to return a enumeration which is called enumSignal. However I do not know what to do, the below code is my attempt.

It highlights the line "_taskFactory.StartNew(_indicator[I].Run)" with the message The call is ambiguous between the following methods.

 public void RunIndicators()
        {
            _taskFactory = new TaskFactory();

            Task<enumSignal>[] taskIndicator = new Task<enumSignal>[_indicator.Length];

            for (int i = 0; i < taskIndicator.Length; i++)
            {

                taskIndicator[i] = _taskFactory.StartNew(_indicator[i].Run);

            }
            Task.WaitAll(taskIndicator);
        }

yes that's what is says but I don't understand why. System.Threading.Tasks.TaskFactory.StartNew(System.Func) and System.Threading.Tasks.TaskFactory.StartNew(System.Action) — mHelpMe, Nov 20 '13 at 20:20
possible duplicate of [c# .net why does Task.Run seem to handle Func differently than other code?](http://stackoverflow.com/questions/11695886/c-sharp-net-why-does-task-run-seem-to-handle-funct-differently-than-other-cod) — Adi Lester, Nov 20 '13 at 20:21

Mike Strobel · Accepted Answer · 2013-11-20T20:55:29.117

0

The C# compiler can't always infer generic delegate types when multiple overloads exist. Try adjusting your StartNew() call as follows:

_taskFactory.StartNew((Func<enumSignal>)_indicator[i].Run)

...or, if you prefer:

_taskFactory.StartNew<enumSignal>(_indicator[i].Run)

This assumes _indicator[i].Run() has no arguments and returns an enumSignal.

edited Nov 20 '13 at 20:55

answered Nov 20 '13 at 20:50

Mike Strobel

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C# Task Return Value

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