Method name expected error

[Alex Dransfield]

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace FindFactors
{
    class Program
    {
        static void Main(string[] args)
        {
            ThreadWork threadwork = new ThreadWork();

            Console.Write("Enter a number to find the factors of: ");
            string max = Convert.ToString(Console.Read());

            Thread countOdd = new Thread(new ThreadStart(threadwork.countOdd(max)));
            Thread countEven = new Thread(new ThreadStart(threadwork.countEven(max)));
        }
    }
}

And here's ThreadWork.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace FindFactors
{
    class ThreadWork
    {
        public void countOdd(string max)
        {
            long i = 0;
            long n = Convert.ToInt64(max);
            for (i = 1; i <= n; i += 2)
            {
                if ((n % i) == 0)
                {
                    Console.WriteLine(i);
                }
            }
        }

        public void countEven(string max)
	    {
		    long j = 0;
		    long o = Convert.ToInt64(max);
		    for (j = 2; j <= o; j+=2)
            	{
                if ((o % j) == 0)
                    {
                        Console.WriteLine(j);
                    }
        }
	}
    }
}

What am I doing wrong here? I keep getting the "Method name expected" error on

Thread countOdd = new Thread(new ThreadStart(threadwork.countOdd(max)));
            Thread countEven = new Thread(new ThreadStart(threadwork.countEven(max)));

but I'm not quite sure why...

[Curtis Rutland]

You're not providing the method name, you're trying to call the method.

You can't call a method with a parameter using a thread, apparently. You could do something like this:

class Program
{
    static void Main()
    {
        ThreadWork tw = new ThreadWork(100);
        Thread countOdd = new Thread(new ThreadStart(tw.CountOdd));
        Thread countEven = new Thread(new ThreadStart(tw.CountEven));
        Console.WriteLine("Odd Factors:");
        countOdd.Start();
        countOdd.Join();
        Console.WriteLine("Even Factors:");
        countEven.Start();
        countEven.Join();
        Console.ReadKey();
    }
}

class ThreadWork
{
    private int max;

    public ThreadWork(int max)
    {
        this.max = max;
    }

    public void CountOdd()
    {
        long i = 0;
        long n = Convert.ToInt64(max);
        for (i = 1; i <= n; i += 2)
        {
            if ((n % i) == 0)
            {
                Console.WriteLine(i);
            }
        }
    }

    public void CountEven()
    {
        long j = 0;
        long o = Convert.ToInt64(max);
        for (j = 2; j <= o; j += 2)
        {
            if ((o % j) == 0)
            {
                Console.WriteLine(j);
            }
        }
    }
}

Note, the way I did the starts and joins, we might as well have just done it synchronously. But it's just to illustrate a point. It makes no sense to have output like that on a separate thread, because if they are executing at the same time, they'll both be outputting at the same time to the console, and you'll get jumbled results. A better approach would be to store the results in a List<int> or two (maybe OddFactors and EvenFactors) to retrieve after they've been calculated.

Anyway, notice how I made the ThreadStart objects: with the method names. No parenthesis. That's actually getting a reference to the method as an object, rather than calling the method.