In ASP.NET Core, caching is done using the IMemoryCache interface. Unlike classic ASP.NET, it doesn’t have a built-in way to enumerate or remove all entries. But you can still manage to Purge ASP.NET Cache by:

Step 1: Use a Cache Wrapper with Keys Tracking

You must track all cache keys manually to remove them later.

public interface ICustomCache
{
    void Set(string key, object value, TimeSpan duration);
    object Get(string key);
    void Remove(string key);
    void ClearAll();
}

public class CustomMemoryCache : ICustomCache
{
    private readonly IMemoryCache _cache;
    private readonly HashSet _cacheKeys = new();

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

    public void Set(string key, object value, TimeSpan duration)
    {
        _cache.Set(key, value, duration);
        _cacheKeys.Add(key);
    }

    public object Get(string key)
    {
        return _cache.TryGetValue(key, out var value) ? value : null;
    }

    public void Remove(string key)
    {
        _cache.Remove(key);
        _cacheKeys.Remove(key);
    }

    public void ClearAll()
    {
        foreach (var key in _cacheKeys.ToList())
        {
            _cache.Remove(key);
            _cacheKeys.Remove(key);
        }
    }
}

Step 2: Register in Startup.cs (or Program.cs for .NET 6+)

builder.Services.AddMemoryCache();
builder.Services.AddSingleton<ICustomCache, CustomMemoryCache>();

Step 3: Use the Custom Cache Anywhere

public class AdminController : Controller
{
    private readonly ICustomCache _cache;

    public AdminController(ICustomCache cache)
    {
        _cache = cache;
    }

    [HttpPost]
    [Authorize(Roles = "Admin")]
    public IActionResult ClearCache()
    {
        _cache.ClearAll();
        return Ok("Cache cleared successfully.");
    }
}

Security Best Practices

• Wrap cache-clearing behind authentication.
• Use role-based access for admins.
• Don’t expose this functionality in a public-facing UI.