twmvc26sample-netcore-caching

淺談 ASP.NET Caching 技術與實踐範例程式碼

ASP.NET Core Caching

NuGet 安裝

Install-Package Microsoft.Extensions.Caching.Memory

Startup 設定

public void ConfigureServices(IServiceCollection services)
{
  services.AddMvc();

  services.AddSingleton<IEmployeeRepository, EmployeeRepository>();
  services.AddSingleton<IService<Employee>, EmployeeService>();

  services.AddMemoryCache();
}

注入服務

private readonly IMemoryCache _memoryCache;
private readonly IService<Employee> _service;

//// 1.注入 IMemoryCache 服務
public EmployeeController(IMemoryCache memCache, IService<Employee> service)
{
  _memoryCache = memCache;
  _service = service;
}

使用方式

public IActionResult Index()
{
  var emps = SetGetMemoryCache();
  return View(emps);
}

private List<Employee> SetGetMemoryCache()
{
  List<Employee> employees;

  //// 2.設定 Cache Key
  string key = "MyMemoryKey-Cache";

  //// 3.我們將嘗試從 Cache 取得資料
  //// 若嘗試取得失敗，則由服務層取得資料，否之從 MemoryCache 直接取出
  if (_memoryCache.TryGetValue(key, out employees) == false)
  {
    //// 4.從服務層取得資料
    employees = _service.GetAll().ToList();

    //// 5.設定快取項目「絕對過期時間」
    var cacheEntryOptions = new MemoryCacheEntryOptions()
        .SetAbsoluteExpiration(TimeSpan.FromSeconds(5));

    //// 6.將取得資料設定進 Cache
    _memoryCache.Set(key, employees, cacheEntryOptions);

    ViewBag.Status = "資料加入到快取";
  }
  else
  {
    employees = _memoryCache.Get(key) as List<Employee>;
    ViewBag.Status = "從快取中取得資料";
  }

  return employees;
}

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以上。

若有不清楚或是需要進一步協助請再讓我知道。謝謝。