How can I wait for a thread to finish with .NET?

Question

I\'ve never really used threading before in C# where I need to have two threads, as well as the main UI thread. Basically, I have the following.

public void S         


        

Answer 1

Here's a simple example that waits for a tread to finish, within the same class. It also makes a call to another class in the same namespace. I included the "using" statements so it can execute as a Windows Forms form as long as you create button1.

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Threading;

namespace ClassCrossCall
{

    public partial class Form1 : Form
    {
        int number = 0; // This is an intentional problem, included
                        // for demonstration purposes
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            button1.Text = "Initialized";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            button1.Text = "Clicked";
            button1.Refresh();
            Thread.Sleep(400);
            List taskList = new List();
            taskList.Add(Task.Factory.StartNew(() => update_thread(2000)));
            taskList.Add(Task.Factory.StartNew(() => update_thread(4000)));
            Task.WaitAll(taskList.ToArray());
            worker.update_button(this, number);
        }

        public void update_thread(int ms)
        {
            // It's important to check the scope of all variables
            number = ms; // This could be either 2000 or 4000. Race condition.
            Thread.Sleep(ms);
        }
    }

    class worker
    {
        public static void update_button(Form1 form, int number)
        {
            form.button1.Text = $"{number}";
        }
    }
}