在高速公路收费系统业务中， 我们的收费站列表信息被频繁各类盘问，来自整个自治区的收费站城市盘问站信息和其他业务，那么对付站信息盘问来说就显得尤其重要，， 因此我们设置过期时间为10分钟。 

//去报using了 下面三个定名空间

using System.Threading; using System.Threading.Tasks; using Microsoft.Extensions.Caching.Memory; namespace Uixe.Blazor.Controllers { [Authorize] [Route("api/[controller]")] [ApiController] public class PlazasController : ControllerBase { private readonly ApplicationDbContext _context; private readonly ILogger _logger; private readonly AppSettings _settings; //内存缓存IMemoryCache private readonly IMemoryCache _memoryCache; //在需要过期的缓存中 AddExpirationToken private CancellationChangeToken _changeToken ; //用于改削时挪用，以使得_changeToken关联的缓存过期 private CancellationTokenSource _cancellationToken; public PlazasController(ApplicationDbContext context, ILogger<PlazasController> logger, IOptions<AppSettings> option,IMemoryCache memoryCache) { _context = context; _logger = logger; _settings = option.Value; _memoryCache = memoryCache; //我们需要将CancellationTokenSource自己也缓存在缓存傍边 _cancellationToken = _memoryCache.GetOrCreate("cts" + nameof(PlazasController), a => { //没当过期后从头创建CancellationTokenSource _cancellationToken = new CancellationTokenSource(); //然后黄建 CancellationChangeToken并关联CancellationTokenSource _changeToken = new CancellationChangeToken(_cancellationToken.Token); //添加至当前缓存元素中以方便_cancellationToken.Canecel()被挪用后，自己也能国企 a.AddExpirationToken(_changeToken); return _cancellationToken; }); } [HttpGet(), AllowAnonymous, Authorize(Roles = nameof(UserRole.Anonymous))] public async Task<ActionResult<List<Plaza>>> GetPlazas() { return await _memoryCache.GetOrCreateAsync("_plaza_GetPlazas", a => { //当完整信息或许返回时关联_changeToken a.AddExpirationToken(_changeToken); //设置如果不改削的过期时间 ， 因为可能会从数据库或者自动措置惩罚惩罚措施会改削后台数据。 //或者其他措施改削了我们并不知道，所以待有过期时间 a.AbsoluteExpirationRelativeToNow = TimeSpan.FromMinutes(10); return _context.Plazas.ToListAsync(); }); } /// <summary> /// 按照指定的参数<paramref/>盘问收费站信息 /// </summary> /// <param></param> /// <returns></returns> [HttpPost("Query"), AllowAnonymous, Authorize(Roles = nameof(UserRole.Anonymous))] public async Task<ActionResult<ApiResultPage<List<Plaza>>>> QueryPlazas([FromBody] phc_PlazaQueryArgs args) { //这是个盘问， 我们按照盘问条件的东西序列化为json，然后取md5字符串作为key if (args == null) args = new phc_PlazaQueryArgs() { currentPage=1, pageSize=10}; var key = "_plaza_" + args.GetMd5Sum(); return await _memoryCache.GetOrCreateAsync(key, async a => { //同样设置过期时间 a.AbsoluteExpirationRelativeToNow = TimeSpan.FromMinutes(10); //将_changeToken进行关联 a.AddExpirationToken(_changeToken); var query = from p in _context.Plazas select p; if (!string.IsNullOrEmpty(args.plazaid)) { query = from q in query where q.Id.Contains(args.plazaid) || q.StationId.StartsWith(args.plazaid) select q; } if (!string.IsNullOrEmpty(args.ipaddress)) { query = from q in query where q.IPAddress.StartsWith(args.ipaddress) select q; } if (!string.IsNullOrEmpty(args.plazaname)) { query = from q in query where q.StationName.Contains(args.plazaname) select q; } int total =await query.CountAsync(); var data = await query.Skip(args.pageSize * (args.currentPage - 1)).Take(args.pageSize).OrderBy(q=>q.Id).ToListAsync(); return new ApiResultPage<List<Plaza>> (ApiCode.OK, "OK", new PageInfo() { Total = total, Current = args.currentPage, PageSize = args.pageSize, TotalPage = (total + args.pageSize - 1) / args.pageSize }, data); }); } [HttpPut(), Authorize(Roles = nameof(UserRole.Administrator))] public async Task<IActionResult> PutPlaza(Plaza plaza) { _context.Entry(plaza).State = EntityState.Modified; try { await _context.SaveChangesAsync(); //当我们改削并生存后，挪用_cancellationToken，它会麦让与之关联所有缓存过期。 _cancellationToken.Cancel(); } catch (DbUpdateConcurrencyException) { if (!PlazaExists(plaza.Id)) { return NotFound(); } else { throw; } } return NoContent(); } [HttpPost, Authorize(Roles = nameof(UserRole.Administrator))] public async Task<ActionResult<Plaza>> PostPlaza(Plaza plaza) { _context.Plazas.Add(plaza); await _context.SaveChangesAsync(); //我们在添加数据时进行打消， _cancellationToken.Cancel(); return CreatedAtAction("GetPlaza", plaza); } } }

Asp.Net Core 实现盘问时缓存改削后缓存过期

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原文地点：https://www.cnblogs.com/MysticBoy/p/12307588.html