善用匿名函數簡化快取存取模式（一）：Lambda 宣告快取與資料來源委派

Lambda 直接建立快取實例

protected static CacheManager<Company> companyCache =
    new CacheManager<Company>(new SmsDatabaseCache<Company>(), key =>
    {
        return SmsDatabase.Instance.Context.Company
            .Where(c => c.ShortNumber == (string)key).SingleOrDefault();
    });

SmsDatabaseCache 整合 LinqContext 生命週期

public class SmsDatabaseCache<TData> : ICache<TData>
{
    Dictionary<object, TData> cache = new Dictionary<object, TData>();
    public SmsDatabaseCache()
    {
        SmsDatabase.Instance.PreDisposing += (s, e) => cache.Clear();
    }
    public TData Get(object key) => cache[key];
    public void Set(object key, TData data) => cache[key] = data;
}

Context 釋放時自動清空快取，避免資料不一致。