Xin chào các bạn, bài viết hôm nay mình sẽ demo cho các bạn ứng dụng chạy bất đồng bộ Async sử dụng Parallel foreach và for trên ngôn ngữ csharp winform.

[C#] Demo Async Parallel foreach and for in winform

Dưới đây, là hình ảnh giao diện demo ứng dụng:

Ở hình ảnh trên các bạn thấy mình nhập vào Num: 500 -> có 500 công việc cần thực hiện.

Một công việc sẽ thực hiện chuyển đổi màu từ trắng => xanh dương => vàng => xanh lá và nếu lỗi thì tô màu đỏ.

TaskTime là thời gian chờ random khi chuyển đổi từng công việc.

Ở bài này mình, mình demo 4 Worker Thread các bạn có thể chạy và xem thời gian hoàn thành của mình method trên.

Video demo Parallel foreach & for:

Source code ứng dụng C#:

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

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

        int taskNumItem, taskTime, errorRate;

        private async void button1_Click(object sender, EventArgs e)
        {
            Text = "Start";
            taskNumItem = Convert.ToInt32(txtNum.Text);
            taskTime = Convert.ToInt32(txtTaskTime.Text);
            errorRate = Convert.ToInt32(txt_error.Text);
            CreateTask(taskNumItem);
            DateTime startTime = DateTime.Now;

            await Task.Run(() => WorkerThread1(taskNumItem, taskTime));
            DateTime endTime = DateTime.Now;


            Text = string.Format("Finish: {0:#,###.###} miliseconds.", (endTime - startTime).TotalMilliseconds);
        }

        private void CreateTask(int taskNumItem)
        {
            flowLayoutPanel1.Controls.Clear();
            for (int i = 0; i < taskNumItem; i++)
            {
                var button = new Button();
                button.Width = 20;
                button.Height = 20;
                button.Margin = new Padding(1);
                button.Name = "button_" + i.ToString();
                flowLayoutPanel1.Controls.Add(button);
            }

        }




        private string WorkerThread4(int num, int taskTime, DateTime startTime)
        {
            Random rnd = new Random();
            int progressCount = 0;
            var source = flowLayoutPanel1.Controls.Cast<Button>();
            var partitioner = Partitioner.Create<Button>(source, EnumerablePartitionerOptions.NoBuffering);

            Parallel.ForEach(partitioner, new ParallelOptions() { MaxDegreeOfParallelism = 2 }, async control =>
            {
                changeColor(control, Color.DodgerBlue);
                await Task.Run(() => System.Threading.Thread.Sleep(rnd.Next(taskTime)));
                changeColor(control, Color.Yellow);
                await Task.Run(() => System.Threading.Thread.Sleep(rnd.Next(taskTime)));
                Color c = Color.Lime;
                if (rnd.Next(100) < errorRate)
                    c = Color.Red;
                changeColor(control, c);
                lock (Thread.CurrentContext)
                    progressCount++;
                reportProgress(progressCount, num, startTime);
            });
            return "Finish";
        }

        private string WorkerThread3(int num, int taskTime, DateTime startTime)
        {
            Random rnd = new Random();
            int progressCount = 0;
            var tasks = new List<Task>();
            Parallel.For(0, num, async i =>
            {
                Control control = flowLayoutPanel1.Controls[i];
                changeColor(control, Color.DodgerBlue);
                await Task.Run(() => System.Threading.Thread.Sleep(rnd.Next(taskTime)));
                changeColor(control, Color.Yellow);
                await Task.Run(() => System.Threading.Thread.Sleep(rnd.Next(taskTime)));
                Color c = Color.Lime;
                if (rnd.Next(100) < errorRate)
                    c = Color.Red;
                changeColor(control, c);
                lock (Thread.CurrentContext)
                    progressCount++;
                reportProgress(progressCount, num, startTime);
            });

            return "Finish";
        }

        private string WorkerThread2(int num, int taskTime)
        {
            Random rnd = new Random();
            int progressCount = 0;

            var source = flowLayoutPanel1.Controls.Cast<Control>();
            Parallel.ForEach(source, control =>
            {
                changeColor(control, Color.DodgerBlue);
                System.Threading.Thread.Sleep(rnd.Next(taskTime));
                changeColor(control, Color.Yellow);
                System.Threading.Thread.Sleep(rnd.Next(taskTime));
                Color c = Color.Lime;
                if (rnd.Next(100) < errorRate)
                    c = Color.Red;
                changeColor(control, c);
                lock (Thread.CurrentContext)
                    progressCount++;
                reportProgress(progressCount, num);
            });
            return "Finish";
        }



        private string WorkerThread1(int num, int taskTime)
        {
            Random rnd = new Random();
            int progressCount = 0;

            Parallel.For(0, num, i =>
            {
                Control control = flowLayoutPanel1.Controls[i];
                changeColor(control, Color.DodgerBlue);
                System.Threading.Thread.Sleep(rnd.Next(taskTime));
                changeColor(control, Color.Yellow);
                System.Threading.Thread.Sleep(rnd.Next(taskTime));
                Color c = Color.Lime;
                if (rnd.Next(100) < errorRate)
                    c = Color.Red;
                changeColor(control, c);
                lock (Thread.CurrentContext)
                    progressCount++;
                reportProgress(progressCount, num);
            });


            return "Finish";
        }

        private async void button4_Click(object sender, EventArgs e)
        {
            Text = "Start";
            taskNumItem = Convert.ToInt32(txtNum.Text);
            taskTime = Convert.ToInt32(txtTaskTime.Text);
            errorRate = Convert.ToInt32(txt_error.Text);
            CreateTask(taskNumItem);
            DateTime startTime = DateTime.Now;

            await Task.Run(() => WorkerThread2(taskNumItem, taskTime));
            DateTime endTime = DateTime.Now;


            Text = string.Format("Finish: {0:#,###.###} miliseconds.", (endTime - startTime).TotalMilliseconds);
        }

        private async void button3_Click(object sender, EventArgs e)
        {
            Text = "Start";
            taskNumItem = Convert.ToInt32(txtNum.Text);
            taskTime = Convert.ToInt32(txtTaskTime.Text);
            errorRate = Convert.ToInt32(txt_error.Text);
            CreateTask(taskNumItem);
            DateTime startTime = DateTime.Now;

            await Task.Run(() => WorkerThread3(taskNumItem, taskTime, startTime));

        }

        private async void button2_Click(object sender, EventArgs e)
        {
            Text = "Start";
            taskNumItem = Convert.ToInt32(txtNum.Text);
            taskTime = Convert.ToInt32(txtTaskTime.Text);
            errorRate = Convert.ToInt32(txt_error.Text);
            CreateTask(taskNumItem);
            DateTime startTime = DateTime.Now;

            await Task.Run(() => WorkerThread4(taskNumItem, taskTime, startTime));

        }

        private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
            Process.Start("https://laptrinhvb.net");
        }
        private void reportProgress(int progressCount, int num, DateTime startTime)
        {
            progressBar1.BeginInvoke(new Action(() =>
            {
                progressBar1.Minimum = 0;
                progressBar1.Maximum = num;
                if (progressCount > num) { return; }
                if (progressCount >= num)
                {
                    DateTime endTime = DateTime.Now;
                    Text = string.Format("Finish: {0:#,###.###} miliseconds.", (endTime - startTime).TotalMilliseconds);
                }
                progressBar1.Value = progressCount;
                lbl_percent.Text = Convert.ToInt32((progressCount / (num * 1.0)) * 100) + " %";


            }));

        }

        private void Form1_Load(object sender, EventArgs e)
        {
          
        }

        private void reportProgress(int progressCount, int num)
        {
            progressBar1.BeginInvoke(new Action(() =>
            {
                progressBar1.Minimum = 0;
                progressBar1.Maximum = num;
                if (progressCount > num) { return; }
                progressBar1.Value = progressCount;
                lbl_percent.Text = Convert.ToInt32((progressCount / (num * 1.0)) * 100) + " %";

            }));

        }

        private void changeColor(Control control, Color dodgerBlue)
        {
            control.BackColor = dodgerBlue;
        }
    }
}

Thanks for watching!

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