Introduction:

Caching is a technique used to store frequently used data in memory to reduce the response time of the application. In .NET Core, there are many libraries available to implement caching, such as MemoryCache, DistributedCache, and ResponseCaching. In this article, we will explore how to implement caching in .NET Core applications using the MemoryCache library.

MemoryCache:

MemoryCache is a simple caching library that stores data in memory. It is available in the Microsoft.Extensions.Caching.Memory package. MemoryCache provides a way to store and retrieve data using a key-value pair. The key is a string that is used to retrieve the data from the cache, and the value is the actual data that is being cached.

To use MemoryCache, we first need to install the Microsoft.Extensions.Caching.Memory NuGet package using the Package Manager Console or the NuGet Package Manager in Visual Studio.

Next, we need to add the following code to the ConfigureServices method in the Startup.cs file:

services.AddMemoryCache();

This code will register the MemoryCache service with the dependency injection system. We can now inject an instance of IMemoryCache into any controller or service where we want to use caching.

To use the MemoryCache, we can inject IMemoryCache into the constructor of the controller or service:

private readonly IMemoryCache _cache;

public MyController(IMemoryCache cache)
{
    _cache = cache;
}

Now we can use the _cache instance to store and retrieve data from the cache.

Storing Data in MemoryCache:

To store data in MemoryCache, we need to call the Set method of the IMemoryCache instance:

_cache.Set("key", "value");

This code will store the string "value" in the cache with the key "key". We can also specify an expiration time for the cached item by passing a TimeSpan object as the second argument:

_cache.Set("key", "value", TimeSpan.FromMinutes(10));

This code will cache the item for 10 minutes. After 10 minutes, the item will be removed from the cache.

Retrieving Data from MemoryCache:

To retrieve data from MemoryCache, we need to call the Get method of the IMemoryCache instance:

var value = _cache.Get("key");

This code will retrieve the value stored in the cache with the key "key". If the item is not found in the cache, the Get method will return null.

Clearing the Cache:

To clear the cache, we can call the Remove method of the IMemoryCache instance:

_cache.Remove("key");

This code will remove the item with the key "key" from the cache.

Conclusion:

Caching is a useful technique to improve the performance of .NET Core applications. MemoryCache is a simple caching library that can be used to store frequently used data in memory. In this article, we explored how to implement caching in .NET Core applications using the MemoryCache library. We learned how to store and retrieve data from the cache and how to clear the cache when necessary. By using caching, we can reduce the response time of our applications and provide a better user experience.