flutter - 试图将 DocumentID 从 ListView 传递给 ¨ Like ¨ Function

Question

我使用 ListView 来显示我从 Firebase 获得的所有帖子，当用户按下按钮时，它们将特殊帖子的 DocumentID 发送到“like”函数，但我收到以下错误:

I/flutter (28036): ══╡ EXCEPTION CAUGHT BY GESTURE 
╞═══════════════════════════════════════════════════════════════════
I/flutter (28036): The following NoSuchMethodError was thrown while handling a gesture:
I/flutter (28036): Class 'QuerySnapshot' has no instance getter 'documentId'.
I/flutter (28036): Receiver: Instance of 'QuerySnapshot'
I/flutter (28036): Tried calling: documentId

已经尝试更改为“documentid”、“documentId”和“documentID”

这是我在按钮中的代码:

onPressed: () => likes(                                                     
  snapshot.data.documentId),

这是我的函数代码:

void likes(String documentid) async {
    await db
        .collection('messages')
        .document(documentid)
        .updateData({'likes': FieldValue.increment(1)});
  }

这就是我构建 ListView 的方式:

new StreamBuilder(
          stream: db
              .collection('messages')
              .orderBy('timestamp', descending: true)
              .snapshots(),
          builder: (context, snapshot) {
            if (snapshot.hasData) {
              return Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: <Widget>[
                  Container(
                    height: 400.0,
                    child: ListView.builder(
... its working, but i dont know how to get the documentID from it.

Answer 1

您确定在 snapshot.data 中有一个 documentId 吗？尝试记录 snapshot.data 以检查它。

编辑以添加代码改变这个

onPressed: () => likes(                                                     
  snapshot.data.documentId),

到

onPressed: ()
{
  print(snapshot.data.toString());
  likes(snapshot.data.documentId);
}