protected override bool Exists(string key) { return AspectF.Define. Cache<bool>(m_DictionaryCache, key). Return(() => { string path = GetFileName(key, false) + "*"; string[] fileNames = m_Store.GetFileNames(path); foreach (string fileName in fileNames) { using (IsolatedStorageFileStream isoFile = new IsolatedStorageFileStream(Path.Combine(WorkFolderPath, fileName), FileMode.Open, FileAccess.Read, m_Store)) { string content = isoFile.ReadToEnd(); if (content == key) { return true; } } } return false; }); }