TPL - 如何强制TPL使用固定的#个线程？不低于

using System;
using System.Threading;
using System.Threading.Tasks;

public class FixedThreadPoolTaskScheduler : TaskScheduler
{
    private readonly int maxDegreeOfParallelism;

    public FixedThreadPoolTaskScheduler(int maxDegreeOfParallelism)
    {
        if (maxDegreeOfParallelism < 1)
            throw new ArgumentOutOfRangeException(nameof(maxDegreeOfParallelism));

        this.maxDegreeOfParallelism = maxDegreeOfParallelism;
    }

    protected override IEnumerable<Task> GetScheduledTasks()
    {
        return Enumerable.Empty<Task>();
    }

    protected override void QueueTask(Task task)
    {
        ThreadPool.QueueUserWorkItem(_ => TryExecuteTask(task));
    }

    protected override bool TryExecuteTaskInline(Task task, bool taskWasPreviouslyQueued)
    {
        return false;
    }

    public override int MaximumConcurrencyLevel => maxDegreeOfParallelism;
}

public class Program
{
    public static void Main()
    {
        int maxDegreeOfParallelism = 4; // 设置线程数量

        TaskFactory factory = new TaskFactory(new FixedThreadPoolTaskScheduler(maxDegreeOfParallelism));

        // 创建并行任务
        Task[] tasks = new Task[10];
        for (int i = 0; i < tasks.Length; i++)
        {
            int index = i; // 避免闭包问题
            tasks[i] = factory.StartNew(() => DoWork(index));
        }

        // 等待所有任务完成
        Task.WaitAll(tasks);

        Console.WriteLine("All tasks completed.");
    }

    private static void DoWork(int index)
    {
        Console.WriteLine($"Task {index} is running on thread {Thread.CurrentThread.ManagedThreadId}.");
        Thread.Sleep(1000); // 模拟任务执行时间
    }
}