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ASP.NET Core 请求限速的ActionFilter

news 2025/7/2 8:30:10

文章目录

前言
一、实现步骤
- 1）创建自定义Action Filter
- - 示例1：
  - 示例2：
- 2）注册服务
- 3）使用
二、实现说明
总结

前言

以下是一个基于内存缓存实现的自定义限流Action Filter。

一、实现步骤

1）创建自定义Action Filter

示例1：

MyRateLimitAttribute.cs

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.Extensions.Caching.Memory;public class MyRateLimitAttribute : TypeFilterAttribute{public MyRateLimitAttribute() :base(typeof(MyRateLimitFilter)){}public class MyRateLimitFilter : IAsyncActionFilter{private readonly IMemoryCache _memoryCache;public MyRateLimitFilter(IMemoryCache memoryCache){_memoryCache = memoryCache;}public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next){string ip = context.HttpContext.Connection.RemoteIpAddress.ToString();if (string.IsNullOrEmpty(ip)){context.Result = new BadRequestObjectResult("Invalid Client IP");return;}string cacheKey = $"MyRateLimit_{ip}";_memoryCache.TryGetValue<long?>(cacheKey, out long? lastVisit);if (lastVisit == null || Environment.TickCount64 - lastVisit > 1000){_memoryCache.Set(cacheKey, Environment.TickCount64, TimeSpan.FromSeconds(10));await next();}else{context.Result = new ObjectResult("访问太频繁") { StatusCode=429};                    }}}}

示例2：

RateLimitAttribute.cs

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.Extensions.Caching.Memory;public class RateLimitAttribute : TypeFilterAttribute
{public RateLimitAttribute(int maxRequests,int secondsWindow) : base(typeof(RateLimitFilter)){Arguments = new object[] { maxRequests,secondsWindow};}public class RateLimitFilter : IAsyncActionFilter{private readonly IMemoryCache _memoryCache;private readonly int _maxRequests;private readonly int _secondsWindow;public RateLimitFilter(IMemoryCache memoryCache, int maxRequests, int secondsWindow){_memoryCache = memoryCache;_maxRequests = maxRequests;_secondsWindow = secondsWindow;}public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next){var ip=context.HttpContext.Connection.RemoteIpAddress?.ToString();if (string.IsNullOrEmpty(ip)){context.Result = new BadRequestObjectResult("Invalid client IP");return;}var cacheKey = $"RateLimit_{ip}";var windowStart = DateTime.UtcNow.AddSeconds(-DateTime.UtcNow.Second % _secondsWindow);if (!_memoryCache.TryGetValue(cacheKey, out RateLimitCounter counter) ||windowStart > counter.WindowStart){counter = new RateLimitCounter{Count = 1,WindowStart = windowStart,};}else{counter.Count++;}if (counter.Count > _maxRequests){context.Result = new ObjectResult("Too many requests"){StatusCode = 429};return;}_memoryCache.Set(cacheKey, counter, counter.WindowStart.AddSeconds(_secondsWindow));await next();}private class RateLimitCounter{public int Count { get; set; }public DateTime WindowStart { get; set; }}}
}

2）注册服务

内存缓存服务
```
builder.Services.AddMemoryCache();
```

3）使用

示例：

[HttpGet]
//[RateLimit(maxRequests: 5, secondsWindow: 60)] // 每分钟最多5次请求
[MyRateLimit]
public async Task<ActionResult<Book>> GetAllBookAsync()
{var res=await _bookRepository.GetAllAsync();return Ok(res);
}