asp.net-core Using InMemory cache in ASP.NET Core application


Example

To use an in memory cache in your ASP.NET application, add the following dependencies to your project.json file:

  "Microsoft.Extensions.Caching.Memory": "1.0.0-rc2-final",

add the cache service (from Microsoft.Extensions.Caching.Memory) to ConfigureServices method in Startup class

services.AddMemoryCache();

To add items to the cache in our application, we will use IMemoryCache which can be injected to any class (for example Controller) as shown below.

private IMemoryCache _memoryCache;
public HomeController(IMemoryCache memoryCache)
{
    _memoryCache = memoryCache;
}

Get will return the value if it exists, but otherwise returns null.

    // try to get the cached item; null if not found
    // greeting = _memoryCache.Get(cacheKey) as string;

    // alternately, TryGet returns true if the cache entry was found
    if(!_memoryCache.TryGetValue(cacheKey, out greeting))

Use the Set method to write to the cache. Set accepts the key to use to look up the value, the value to be cached, and a set of MemoryCacheEntryOptions. The MemoryCacheEntryOptions allow you to specify absolute or sliding time-based cache expiration, caching priority, callbacks, and dependencies. One of the sample below-

_memoryCache.Set(cacheKey, greeting,
                new MemoryCacheEntryOptions()
                .SetAbsoluteExpiration(TimeSpan.FromMinutes(1)));