我试图从 cloud firestore 获取文档，但我无法，因为“没有为类型 'QuerySnapshot' 定义 getter 'documents'答案

【问题标题】：I tried to get the documents from cloud firestore but I am unable, due to "The getter 'documents' isn't defined for the type 'QuerySnapshot'我试图从 cloud firestore 获取文档，但我无法，因为“没有为类型 'QuerySnapshot' 定义 getter 'documents'
【发布时间】：2021-03-23 11:26:41
【问题描述】：

addData(){
    Map<String, dynamic> Demodata = {"Name": "The growing developer",
    "motto":"Let's grow and learn together"
    };

    CollectionReference collectionReference = FirebaseFirestore.instance.collection('Patients');
    collectionReference.add(Demodata);
  }

  FectchData(){
    CollectionReference collectionReference = FirebaseFirestore.instance.collection('Patients');
    collectionReference.snapshots().listen((snapshot) {

      List documents;
      setState(() {
        documents = snapshot.**documents**;<---- the word 'document' is uderlined 
                                                 by red color line
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Create a new record"),
        centerTitle: true,
      ),

      body: Center(
        child: Column(
          children: <Widget>[
            ElevatedButton(onPressed: FectchData
                , child: Text(
                  "Patient details",
                )),
            ElevatedButton(onPressed: (){

            }, child: Text(
              "Contact Details",
            )),
            ElevatedButton(onPressed: (){

            }, child: Text(
              "Allergies/Adverse drug reaction",
            )),ElevatedButton(onPressed: (){

            }, child: Text(
              "Immunisation Status",
            )),
            ElevatedButton(onPressed: (){}, child:
            Text(
              "Pregnancy details",
            )),

            ElevatedButton(onPressed: (){}, child:
            Text(
              "BreastFeeding details",
            )),
            ElevatedButton(onPressed: (){}, child:
            Text(
              "Social History details",
            )),
            ElevatedButton(onPressed: (){}, child:
            Text(
              "Past Medical History",
            )),
            ElevatedButton(onPressed: (){}, child:
            Text(
              "Medications and Supplements",
            )),

          ],
        ),
      ),
    );
  }
}

【问题讨论】：

标签： flutter google-cloud-firestore

【解决方案1】：

要从 snapshots() 获取文档列表，您需要调用 data docs

    snapshot.data.docs

请注意，您没有处理错误和连接状态，并且您的代码容易出错。你可以在documentation阅读更多内容。

【讨论】：

【解决方案2】：

我建议您使用StreamBuilder 以便更轻松地处理流的状态。你可以这样尝试：

StreamBuilder<QuerySnapshot>(
  stream: collectionReference.snapshots(),
  builder: (context, snapshot) {
    if (!snashot.hasData) {
      // Do something...
    }
    var _documents = snapshot.data.docs;
    return Center(
      child: Column(
        children: <Widget>[
          ElevatedButton(onPressed: (){}
              , child: Text(
                "Patient details",
              )),
          ElevatedButton(onPressed: (){

          }, child: Text(
            "Contact Details",
          )),
          ElevatedButton(onPressed: (){

          }, child: Text(
            "Allergies/Adverse drug reaction",
          )),ElevatedButton(onPressed: (){

          }, child: Text(
            "Immunisation Status",
          )),
          ElevatedButton(onPressed: (){}, child:
          Text(
            "Pregnancy details",
          )),

          ElevatedButton(onPressed: (){}, child:
          Text(
            "BreastFeeding details",
          )),
          ElevatedButton(onPressed: (){}, child:
          Text(
            "Social History details",
          )),
          ElevatedButton(onPressed: (){}, child:
          Text(
            "Past Medical History",
          )),
          ElevatedButton(onPressed: (){}, child:
          Text(
            "Medications and Supplements",
          )),
        ],
      ),
    );
  },
),

关于StreamBuilder：here

【讨论】：