c# - 从线程返回值？

Question

我对编程非常陌生，希望您能为我提供帮助。我的任务是使3个不同的线程读取具有给定int的txt文件。然后必须打印出这些值的总和。我想从我创建的三个线程访问int。我怎样才能做到这一点？

这是我的一些代码:

class Program
{
    static void Main()
    {

        Thread t1 = new Thread(ReadFile1);
        Thread t2 = new Thread(ReadFile2);
        Thread t3 = new Thread(ReadFile3);
        t1.Start();
        t2.Start();
        t3.Start();

        System.Console.WriteLine("Sum: ");
        Console.WriteLine();                                                                                        

        Console.WriteLine("");
        System.Console.ReadKey();                                                                                                 

    }

    public static void ReadFile1()
    {

        System.IO.StreamReader file1 = new System.IO.StreamReader({FILEDESTINATION});        
        int x = int.Parse(file1.ReadLine());

    }

Answer 1

试试看...

class Program
{

    static int? Sum = null;
    static Object lockObject = new Object();

    static void Main()
    {
        Thread t1 = new Thread(ReadFile);
        Thread t2 = new Thread(ReadFile);
        Thread t3 = new Thread(ReadFile);
        t1.Start(@"C:\Users\Mike\Documents\SomeFile1.txt");
        t2.Start(@"C:\Users\Mike\Documents\SomeFile2.txt");
        t3.Start(@"C:\Users\Mike\Documents\SomeFile3.txt");

        t1.Join();
        t2.Join();
        t3.Join();

        if (Sum.HasValue)
        {
            System.Console.WriteLine("Sum: " + Sum.ToString());
        }
        else
        {
            System.Console.WriteLine("No values were successfully retrieved from the files!");
        }
        Console.WriteLine("");
        Console.Write("Press Enter to Quit");
        System.Console.ReadLine();
    }

    public static void ReadFile(Object fileName)
    {
        try
        {
            using (System.IO.StreamReader file1 = new System.IO.StreamReader(fileName.ToString()))
            {
                int x = 0;
                string line = file1.ReadLine();
                if (int.TryParse(line, out x))
                {
                    lock (lockObject)
                    {
                        if (!Sum.HasValue)
                        {
                            Sum = x;
                        }
                        else
                        {
                            Sum = Sum + x;
                        }
                    }
                }
                else
                {
                    Console.WriteLine("Invalid Integer in File: " + fileName.ToString() + "\r\nLine from File: " + line);
                }
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine("Exception Reading File: " + fileName.ToString() + "\r\nException: " + ex.Message);
        }
    }

}