跨线程 C# [重复]答案

【问题标题】：Cross-threading C# [duplicate]跨线程 C# [重复]
【发布时间】：2016-04-18 19:47:37
【问题描述】：

我之前一直在学习线程，但使用的是 C++。现在我第一次尝试将此代码配置为正确工作，但没有 CheckIllegal ... = false。我一直在尝试将代表和许多其他东西放在那里，但我遇到了同样的问题。两个线程都进入方法 WriteInLog ，我真的不知道如何使这项工作。有人有想法和解释吗？

namespace viseNitniRad
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();


        }
        private int firstNum = 0;
        private int secondNum = 0;
        public Thread firstThread;
        public Thread secondThread;

        public  void WriteInLog(string message)
        {
            lock (textBox3)
            {
                textBox3.Text += message + Environment.NewLine;
            }
        }

        private void CheckInput()
        {
            int pom = 0;
            firstNum = int.Parse(textBox1.Text);
            secondNum = int.Parse(textBox2.Text);
            if (firstNum > secondNum) {
                pom = secondNum;
                secondNum = firstNum;
                firstNum = pom; }

            WriteInLog("Prvi broj: " + firstNum.ToString());
            WriteInLog("Drugi broj: " + secondNum.ToString());
        }


        private void button1_Click(object sender, EventArgs e)
        {
            CheckInput();

        }

        public delegate void ThreadSum();
        public delegate void ThreadUmn();
        public void Threadsumm()
        {
            int suma = 0;
            for (int i = firstNum; i < secondNum; i++)
                suma += i;
            WriteInLog("Suma= " + suma.ToString() + " kraj: " + DateTime.Now.ToString());

        }

        public  void ThreadUmno()
        {
            int umnozak = 1;
            for (int i = firstNum; i < secondNum; i++)
                umnozak*= i;
            WriteInLog("Umnozak= " + umnozak.ToString() + " kraj: " + DateTime.Now.ToString());
        }

        private void button2_Click(object sender, EventArgs e)
        {
            WriteInLog("Pocetak svih izracuna u: " + DateTime.Now.ToString());

            firstThread = new Thread(new ThreadStart(Threadsumm));
          secondThread = new Thread(new ThreadStart(ThreadUmno));


            firstThread.Start();
            secondThread.Start();


        }
    }
}

【问题讨论】：

不要锁定文本框等 UI 元素，锁定对象类型的私有字段。

标签： c# multithreading delegates thread-safety

【解决方案1】：

要从非 UI 线程访问控制，您必须使用 Control.Invoke 方法 https://msdn.microsoft.com/en-us/library/a1hetckb(v=vs.110).aspx

你可以使用 BackgroundWorker 而不是线程 https://msdn.microsoft.com/en-us/library/cc221403(v=vs.95).aspx

还有： WinForm Multithreading. Use backgroundWorker or not?

【讨论】：

【解决方案2】：

如果有人来到这里并想知道这个问题的确切答案，这里就是。我不想改变任何东西，所以我学习了一些关于调用的东西。此外，这是代码

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


namespace viseNitniRad
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();


        }
        private int firstNum = 0;
        private int secondNum = 0;
        public Thread firstThread;
        public Thread secondThread;

        public  void WriteInLog(string message)
        {
            if (this.textBox3.InvokeRequired)
            {
                ThreadSum ts = new ThreadSum(WriteInLog);
                this.Invoke(ts, new object[] { message });

            }
            else
            {
                this.textBox3.Text += message + Environment.NewLine;
            }
        }

        private void CheckInput()
        {
            int pom = 0;
            firstNum = int.Parse(textBox1.Text);
            secondNum = int.Parse(textBox2.Text);
            if (firstNum > secondNum) {
                pom = secondNum;
                secondNum = firstNum;
                firstNum = pom; }

            WriteInLog("Prvi broj: " + firstNum.ToString());
            WriteInLog("Drugi broj: " + secondNum.ToString());
        }


        private void button1_Click(object sender, EventArgs e)
        {
            CheckInput();

    }
        public delegate void ThreadSum(string message);
        public delegate void ThreadUmn();
        public void Threadsumm()
        {
            int suma = 0;
            for (int i = firstNum; i < secondNum; i++)
                suma += i;
            WriteInLog("Suma= " + suma.ToString() + " kraj: " + DateTime.Now.ToString());

        }
        public  void ThreadUmno()
        {
            int umnozak = 1;
            for (int i = firstNum; i < secondNum; i++)
                umnozak*= i;
            WriteInLog("Umnozak= " + umnozak.ToString() + " kraj: " + DateTime.Now.ToString());
        }

        private void button2_Click(object sender, EventArgs e)
        {
            WriteInLog("Pocetak svih izracuna u: " + DateTime.Now.ToString());

            firstThread = new Thread(new ThreadStart(Threadsumm));
          secondThread = new Thread(new ThreadStart(ThreadUmno));


            firstThread.Start();

            secondThread.Start();


        }
    }
}

如您所见，我在函数 WriteInLog 中几乎没有更改，我删除了 lock 方法并设置了一个条件 if invokeRequired 来初始化 Delegate 以运行相同的方法，而不是调用他，如果不是，则只是更新相同的 textbox3。谢谢你们！ :)

【讨论】：