我正在使用ews来阅读来自office365的电子邮件，我正在尝试存储邮件标题的缓存，所以当我阅读i juat sue Syncstaste以获取delta时。 我可以在哪里保存这个？
bool moreChangesAvailable = false; do { // Get a list of all items in the Inbox by calling SyncFolderHierarchy repeatedly until no more changes are available. // The folderId parameter must be set to the root folder to synchronize, // and must be same folder ID as used in previous synchronization calls. // The propertySet parameter is set to IdOnly to reduce calls to the Exchange database, // because any additional properties result in additional calls to the Exchange database. // The ignoredItemIds parameter is set to null, so that no items are ignored. // The maxChangesReturned parameter is set to return a maximum of 10 items (512 is the maximum). // The syncScope parameter is set to Normal items, so that associated items will not be returned. // The syncState parameter is set to cSyncState, which should be null in the initial call, // and should be set to the sync state returned by the // previous SyncFolderItems call in subsequent calls. ChangeCollection<ItemChange> icc = service.SyncFolderItems(new FolderId(WellKnownFolderName.Inbox), PropertySet.IdOnly, null, 10, SyncFolderItemsScope.NormalItems, cSyncState); // If the count of changes is zero, there are no changes to synchronize. if (icc.Count == 0) { Console.WriteLine("There are no item changes to synchronize."); } // Otherwise, write all the changes included in the response // to the console. else { foreach (ItemChange ic in icc) { Console.WriteLine("ChangeType: " + ic.ChangeType.ToString()); Console.WriteLine("ItemId: " + ic.ItemId); Console.WriteLine("==========="); } } // Save the sync state for use in future SyncFolderContent requests. // The sync state is used by the server to determine what changes to report // to the client. string sSyncState = icc.SyncState; // Determine whether more changes are available on the server. moreChangesAvailable = icc.MoreChangesAvailable; } while (moreChangesAvailable);