制作流構建器 stream：一個變量會破壞 stream 構建器

Question

我正在嘗試制作一個可以查詢我的 firestore 數據庫並返回結果的搜索欄。

我有一個看起來像這樣的 stream 構建器：

StreamBuilder(
        //query to firestore db
        stream:  streamQuery,
        //builds widget for loading and compleation
        builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {...

引發此錯誤：

無法推斷類型參數“T”。

Tried to infer 'dynamic' for 'T' which doesn't work:
  Parameter 'builder' declared as     'Widget Function(BuildContext, AsyncSnapshot<T>)'
                      but argument is 'Widget Function(BuildContext, AsyncSnapshot<QuerySnapshot<Object?>>)'.
The type 'dynamic' was inferred from:
  Parameter 'stream' declared as     'Stream<T>?'
                     but argument is 'Stream<dynamic>'.

Consider passing explicit type argument(s) to the generic.

奇怪的是，如果我用這個替換stream: ：

db
        .collection('GearLockerItems')
        .where('itemName', isGreaterThanOrEqualTo: searchKey)
        .where('itemName', isLessThan: '${searchKey}z')
        .where('communityShare', isEqualTo: true)
        .where('reviewed', isEqualTo: true)
        .snapshots();

然后它工作。 將該firestore stream 保存到變量中會破壞事情。 作為參考，我正在嘗試關注這個 Stack Overflow 問題：

https://stackoverflow.com/a/60873879/522607

Answer 1

我必須將StreamBuilder<dynamic>添加到 Stream Builder：

body: StreamBuilder<dynamic>(
        stream: streamQuery,
        builder: (BuildContext context, AsyncSnapshot<dynamic> snapshot) {...