GetUserTask.cs

public sealed class GetUserTask : TaskActivity<string, string>
{
    public GetUserTask()
    {
    }

    protected override string Execute(DurableTask.TaskContext context, string input)
    {
        GetUserName userNamedialog = new GetUserName();
        Console.WriteLine("Waiting for user to enter name...");
        string user = "";
        DialogResult dialogResult = userNamedialog.ShowDialog();
        if (dialogResult == DialogResult.OK)
        {
            user = userNamedialog.UserName;
        }
        Console.WriteLine("User Name Entered: " + user);

        return user;
    }
}