C# custom task.run() does not execute function

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I have a very simple custom Task.Run() method.
Using the .net Task.Run() method works fine, the custom method does not execute the action.

Any ideas?

What I have tried:

Usage:

//works
      Task.Run(() => TestTasks.CustomTasks.DummyTask());

      //does not work
      TestHelpers.Tasks.Run(TestTasks.CustomTasks.DummyTask);

Code:

namespace TestHelpers
{
    public static class Tasks
    {
        public static string Run(Action action)
        {
            try
            {
                Task.Run(() => action);
                return "ok";
            }
            catch (Exception ex)
            {
                return ex.Message;
            }

        }
    }
}

namespace TestTasks
{
    public static class CustomTasks
    {
        public static void DummyTask()
        {
            for (int i = 0; i < 10; i++)
                System.Threading.Thread.Sleep(100);
        }
    }
}

Posted 18-Feb-19 22:25pm

Sni.DelWoods

Updated 18-Feb-19 22:55pm

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TheRealSteveJudge · Accepted Answer · 2019-02-18T22:55:00

Solution 1

You must replace

Task.Run(() => action);

by

Task.Run(action);

Please have a look at Task.Run Method (System.Threading.Tasks) | Microsoft Docs[^]
The syntax is

public static System.Threading.Tasks.Task Run (Action action);

Posted 18-Feb-19 22:55pm

TheRealSteveJudge

Updated 18-Feb-19 22:57pm

v2

Comments

Sni.DelWoods 19-Feb-19 5:57am

Great, this works. Thank you!

By the way:
Why do I have use the method directly instead of using a lambda?
As I can see the .net method has the same signature: Run (Action action)

And why do I HAVE to use a lambda if my method uses parameters?

 public static void DummyTask(string param) {...}

 TestHelpers.Tasks.Run(() => TestTasks.CustomTasks.DummyTask("My parameter"));

TheRealSteveJudge 19-Feb-19 6:10am

You're welcome.
According to the documentation the method 'Run' has an object of type 'Action' as parameter.
Your 'TestHelpers.Tasks.Run' Method also has an object of type 'Action' as parameter.

Sni.DelWoods 19-Feb-19 7:10am

Yes, that's what I detected. But why can't I use a lambda ()=>method.
I would have expected there's no difference between my Task.Run and the Threading.Tasks.Task.Run.
(Just want to understand what's happening here...Some things won't get in my mind...)

Richard Deeming 20-Feb-19 9:25am

Task.Run(action)

- Returns a Task which executes the specified action.

Task.Run(() => action());

- Returns a Task which executes an anonymous method which executes the action.

Task.Run(() => action);

- Returns a Task<Action> which executes an anonymous method which returns the action. The action is not executed.

TheRealSteveJudge 19-Feb-19 7:56am

TestHelpers.Tasks.Run(new Action(TestTasks.CustomTasks.DummyTask));

is the same as

TestHelpers.Tasks.Run(TestTasks.CustomTasks.DummyTask);

In

Task.Run(() => TestTasks.CustomTasks.DummyTask());

you have brackets.

There is no need to write 'new Action(TestTasks.CustomTasks.DummyTask)' as it is a redundant explicit delegate creation.