我是 Cloud Firestore 的新手。當(dāng)我閱讀文檔時(shí)，我看到了下面的代碼：DocumentReference docRef = db.Collection("cities").Document("SF");FirestoreChangeListener listener = docRef.Listen(snapshot =>{    Console.WriteLine("Callback received document snapshot.");    Console.WriteLine("Document exists? {0}", snapshot.Exists);    if (snapshot.Exists)    {        Console.WriteLine("Document data for {0} document:", snapshot.Id);        Dictionary<string, object> city = snapshot.ToDictionary();        foreach (KeyValuePair<string, object> pair in city)        {            Console.WriteLine("{0}: {1}", pair.Key, pair.Value);        }    }});實(shí)際上，我知道如何通過過濾查詢進(jìn)行偵聽并偵聽查詢快照中的所有 300 條記錄，但是即使只有一個(gè)文檔更新，查詢也會(huì)讀取所有記錄，并且會(huì)顯著增加讀取計(jì)數(shù)（成本也會(huì)增加）。如果我有 300 個(gè)文檔，并且我想通過文檔參考快照收聽所有文檔的實(shí)時(shí)更新，該怎么辦？ 會(huì)有 300 個(gè)獨(dú)立的套接字還是一個(gè)單例套接字來監(jiān)聽所有這些套接字。C# 驅(qū)動(dòng)程序和 Flutter 驅(qū)動(dòng)程序行為相同嗎？實(shí)施將是這樣的；foreach (var docRef in docRefList) //300 records{    FirestoreChangeListener listener = docRef.Listen(snapshot =>    {        Console.WriteLine("Callback received document snapshot.");        Console.WriteLine("Document exists? {0}", snapshot.Exists);        if (snapshot.Exists)        {            Console.WriteLine("Document data for {0} document:", snapshot.Id);            Dictionary<string, object> city = snapshot.ToDictionary();            foreach (KeyValuePair<string, object> pair in city)            {                Console.WriteLine("{0}: {1}", pair.Key, pair.Value);            }        }    });}