為了並行執行多個任務，可以啟動多個進程（並行數）。

下面提供兩種方法，總任務數10，最大並行數4。

一、方法1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Threading;

namespace 進程並行
{
   public class StartProcess1
    {
        int totalProcess = 10
 
;//總任務數
        int maxParallelProcess = 4;//並行最大進程數
        int curRunningProcess = 0;//當前運行進程數
        public void Do()
        {
            DoEvents();
        }

        /// <summary>
        /// 執行進程
        /// </summary>
        private  void DoEvents()
        {
            for (int i = 0; i < totalProcess; i++)
            {
                ProcessStartInfo processInfo 
 
= new ProcessStartInfo();
                processInfo.FileName = @"C:\進程.exe";
                processInfo.Arguments = (i + 1).ToString();
                Process pro = new Process();
                pro.EnableRaisingEvents = true;
                pro.StartInfo = processInfo;
                pro.Exited 
 
+= new EventHandler(process_Exited);
                pro.Start();
                //pro.WaitForExit(18000);
                curRunningProcess++;
                //如果大於最大並行數，就等待進程退出，是並行數不超過最大並行數
                while (curRunningProcess >= maxParallelProcess)
                {
                    if (i >= totalProcess - 1)
                    { return; }
                }
            }
        }

        /// <summary>
        /// 進程結束
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
       private void process_Exited(object sender, EventArgs e)
        {
            curRunningProcess--;
        }
    }
}

二、方法2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Threading;

namespace 進程並行
{
   public class StartProcess2
    {
        static int totalProcess = 10;//總任務數
        static int maxParallelProcess = 4;//並行最大進程數
        static int doneProcess = 0;//已經執行完的進程數
        static int toPro = 0;//第一次啟動的進程數
        public  void Do2()
        {
            //當總任務數小於進程並行數時啟動totalProcess個進程
            toPro = totalProcess < maxParallelProcess ? totalProcess : maxParallelProcess;
            for (int i = 0; i < toPro; i++)
            {
                doneProcess++;
                DoEvents2();
            }
            //任務全部執行後再結束主進程
            while (doneProcess < totalProcess)
            {

            }
        }

        /// <summary>
        /// 執行進程
        /// </summary>
        private  void DoEvents2()
        {
            ProcessStartInfo processInfo = new ProcessStartInfo();
            processInfo.FileName = @"C:\進程.exe";
            processInfo.Arguments = (doneProcess).ToString();
            Process pro = new Process();
            pro.EnableRaisingEvents = true;
            pro.StartInfo = processInfo;
            pro.Exited += new EventHandler(process_Exited2);
            pro.Start();
            //pro.WaitForExit(18000)//等待最多18秒退出進程
        }

        /// <summary>
        /// 進程結束
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
       private void process_Exited2(object sender, EventArgs e)
        {
            doneProcess++;
            toPro--;//第一次要啟動的四個進程還沒有完全啟動
            if (doneProcess <= totalProcess)
            {
                DoEvents2();//結束一個進程，再啟動一個進程
            }
        }
    }
}

三、進程

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Threading;

namespace 進程
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(string.Format("這是第{0}個進程", args));
            Thread.Sleep(3000);
        }
    }
}

四、用戶調用

<Window x:Class="進程並行.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <Style TargetType="Button">
            <Setter Property="Width" Value="50"></Setter>
            <Setter Property="Height" Value="50"></Setter>
            <Setter Property="HorizontalAlignment" Value="Center"></Setter>
            <Style.Triggers>
                <Trigger Property="IsMouseOver" Value="true">
                    <Setter Property="Background" Value="Blue"></Setter>
                </Trigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition></RowDefinition>
            <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>
        <Button Click="Button_Click_1">方法1</Button>
        <Button Grid.Row="1" Click="Button_Click_2">方法2</Button>
    </Grid>
</Window>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace 進程並行
{
    /// <summary>
    /// MainWindow.xaml 的交互邏輯
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        /// <summary>
        /// 方法1
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Button_Click_1(object sender, RoutedEventArgs e)
        {
            StartProcess1 proStart1 = new StartProcess1();
            proStart1.Do();
        }

        /// <summary>
        /// 方法2
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Button_Click_2(object sender, RoutedEventArgs e)
        {
            StartProcess2 proStart2 = new StartProcess2();
            proStart2.Do2();
        }
    }
}

C#多進程並行