C#中的并发编程与.NET任务并行库的使用示例和常见问题

using System;
using System.Collections.Concurrent;
using System.Threading;

public class ConcurrentExample
{
    private static readonly ConcurrentDictionary<int, string> _dictionary = new ConcurrentDictionary<int, string>();

    public static void Main()
    {
        // 添加元素
        _dictionary.TryAdd(1, "Hello");
        _dictionary.TryAdd(2, "World");

        // 并发更新
        Thread thread = new Thread(() =>
        {
            _dictionary[1] = "Updated";
        });
        thread.Start();
        thread.Join();

        // 安全地读取
        if (_dictionary.TryGetValue(1, out string value))
        {
            Console.WriteLine(value); // 输出: Updated
        }
    }
}

using System;
using System.Threading.Tasks;

public class TaskParallelExample
{
    public static void Main()
    {
        var tasks = new Task[]
        {
            Task.Run(() => Console.WriteLine("Task 1 started")),
            Task.Run(() => { throw new Exception("Task 2 failed"); }),
            Task.Run(() => Console.WriteLine("Task 3 started"))
        };

        try
        {
            Task.WaitAll(tasks);
        }
        catch (AggregateException ex)
        {
            foreach (var innerEx in ex.InnerExceptions)
            {
                Console.WriteLine($"Error: {innerEx.Message}");
            }
        }

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