dotnet add package StackExchange.Redis

{
  "ConnectionStrings": {
    "Redis": "localhost:6379"
  }
}

using StackExchange.Redis;
using System;
using System.Threading.Tasks;

public class RedisDistributedLock
{
    private readonly IDatabase _redisDatabase;
    private readonly string _lockKey;
    private readonly string _lockValue;
    private readonly TimeSpan _expiry;

    public RedisDistributedLock(IDatabase redisDatabase, string lockKey, string lockValue, TimeSpan expiry)
    {
        _redisDatabase = redisDatabase;
        _lockKey = lockKey;
        _lockValue = lockValue;
        _expiry = expiry;
    }

    public async Task<bool> AcquireLockAsync()
    {
        // 嘗試設(shè)置鎖，僅當(dāng)鍵不存在時(shí)才成功
        return await _redisDatabase.StringSetAsync(_lockKey, _lockValue, _expiry, When.NotExists);
    }

    public async Task ReleaseLockAsync()
    {
        // 使用 Lua 腳本確保只有鎖的持有者才能釋放鎖
        var luaScript = @"
            if redis.call('GET', KEYS[1]) == ARGV[1] then
                return redis.call('DEL', KEYS[1])
            else
                return 0
            end";

        await _redisDatabase.ScriptEvaluateAsync(luaScript, new RedisKey[] { _lockKey }, new RedisValue[] { _lockValue });
    }
}

// 添加 Redis 服務(wù)
builder.Services.AddSingleton<IConnectionMultiplexer>(sp =>
ConnectionMultiplexer.Connect(builder.Configuration.GetConnectionString("Redis")));

using Microsoft.AspNetCore.Mvc;
using StackExchange.Redis;
using System;
using System.Threading.Tasks;

    [ApiController]
    [Route("api/[controller]")]
    public class PaymentController : ControllerBase
    {
        private readonly IDatabase _redisDatabase;

        public PaymentController(IConnectionMultiplexer redis)
        {
            _redisDatabase = redis.GetDatabase();
        }

        [HttpPost("pay")]
        public async Task<IActionResult> ProcessPayment([FromBody] PaymentRequest request)
        {
            // 創(chuàng)建分布式鎖
            var lockKey = $"PaymentLock:{request.OrderId}"; // 鎖的鍵，基于訂單 ID
            var lockValue = Guid.NewGuid().ToString(); // 鎖的值，確保唯一性
            var expiry = TimeSpan.FromSeconds(10); // 鎖的過期時(shí)間

            var distributedLock = new RedisDistributedLock(_redisDatabase, lockKey, lockValue, expiry);

            try
            {
                // 嘗試獲取鎖
                if (await distributedLock.AcquireLockAsync())
                {
                    Console.WriteLine("已獲取鎖，正在處理付款...");

                    // 模擬支付處理
                    bool paymentSuccess = await ProcessPaymentAsync(request.UserId, request.OrderId, request.Amount);

                    if (paymentSuccess)
                    {
                        return Ok(new { Message = "付款成功!" });
                    }
                    else
                    {
                        return BadRequest(new { Message = "付款失敗!" });
                    }
                }
                else
                {
                    return Conflict(new { Message = "正在處理此訂單的另一個(gè)付款請求..." });
                }
            }
            finally
            {
                // 釋放鎖
                await distributedLock.ReleaseLockAsync();
            }
        }

      
    }

POST /api/payment/pay
Content-Type: application/json

{
    "userId": "9527",
    "orderId": "202501061410455506968463210"
    }