C# 多线程，锁lock

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            TextBox.CheckForIllegalCrossThreadCalls = false;  //跨线程访问，一般不用该方式
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Thread thread1 = new Thread(AddSum);
            thread1.IsBackground = true;
            thread1.Start();

            Thread thread2 = new Thread(AddSum);
            thread2.IsBackground = true;
            thread2.Start();
        }

        private static readonly object obj = new object();  //自定义的一个资源

        private void AddSum()
        {
            lock (obj)   //为资源obj加锁
            {

                for (int i = 0; i < 2000; i++)
                {
                    int a = Convert.ToInt32(this.textBox1.Text);
                    a++;
                    this.textBox1.Text = a.ToString();
                }
            }
        }
    }
}