.documentID没有返回正确的信息

Question

问题

我创建了一个下拉菜单，当用户单击某些项目时，它为他们提供了将其删除的选项。但是，当我尝试获取所选项目的文档ID时，它将返回我所选内容的值。

示例

当我在下拉菜单中单击“电子邮件”时，它会打印“ Email”，它是来自文档DjgTDgbW4CkHMURnz32T的字段值“名称”：“电子邮件”。但是，当我尝试打印“电子邮件”的文档ID时，只会打印字段值。

到目前为止已测试

到目前为止，我知道userDocSTRING和userCatSTRING是正确的，并且当我打印_selectedCATEGORY时，也会打印正确的值。但是由于某种原因，当我将.documentID放在末尾时，将改为打印“ Email”。 Flutter Doctor不返回任何错误，也不会打印错误日志。

代码

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firepass/Assets/Colors/colors.dart';
import 'package:flutter/material.dart';
import 'package:firepass/Firebase/login_auth.dart';

// Instantiate stream for listening to category changes
// Used in all dropdown menus
class CategorySettings extends StatefulWidget {
  CategorySettingsSTATE createState() => CategorySettingsSTATE();
}

class CategorySettingsSTATE extends State<CategorySettings> {
  var selectedCATEGORY;
  bool _deleteABLE = false;
  @override
  Widget build(BuildContext context) {
    return StreamBuilder<QuerySnapshot>(
        stream: Firestore.instance
            .collection('users')
            .document(userDocSTRING.toString())
            .collection(userCatSTRING.toString())
            .snapshots(),
        builder: (context, snapshot) {
          if (!snapshot.hasData) {
            return Center(child: CircularProgressIndicator());
          } else {
            List<DropdownMenuItem> catItems = [];
            for (int i = 0; i < snapshot.data.documents.length; i++) {
              DocumentSnapshot snap = snapshot.data.documents[i];
              catItems.add(DropdownMenuItem(
                child: Text(snap.data['Name']),
                value: "${snap.data['Name']}",
              ));
            }

            return Column(children: <Widget>[
              DropdownButton(
                  items: catItems.toList(),
                  onChanged: (categoryVALUE) {
                    setState(() {
                      selectedCATEGORY = categoryVALUE;
                      DeleteButtonSTATE().delete = categoryVALUE;
                      if (categoryVALUE == 'All') {
                        _deleteABLE = false;
                        print(
                            'Category can be deleted ==== ${_deleteABLE.toString()}');
                      } else
                        _deleteABLE = true;
                      print(categoryVALUE.toString());
                    });
                  },
                  value: selectedCATEGORY,
                  isExpanded: false),
              _deleteABLE == true
                  ? DeleteBUTTON()
                  : Container(height: 0.0, width: 0.0)
            ]);
          }
        });
  }
}

class DeleteBUTTON extends StatefulWidget {
  DeleteButtonSTATE createState() => DeleteButtonSTATE();
}

class DeleteButtonSTATE extends State<DeleteBUTTON> {
  var delete;
  Widget build(BuildContext context) {
    return Column(children: <Widget>[
      Padding(padding: EdgeInsets.all(12)),
      IconButton(
          icon: Icon(Icons.lightbulb_outline),
          onPressed: () {
            print(delete.toString());
          }),
      GestureDetector(
          onTap: () {
            print('Category ${CategorySettingsSTATE().toString()} Deleted');

            Firestore.instance
                .collection('users')
                .document(userDocSTRING.toString())
                .collection(userCatSTRING.toString())
                .document(CategorySettingsSTATE().selectedCATEGORY.toString())
                .delete();
          },
          child: Card(
              shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(20)),
              margin: EdgeInsets.symmetric(horizontal: 80),
              elevation: 0,
              color: accentRedColor,
              child: Padding(
                  padding: EdgeInsets.all(10),
                  child: Row(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: <Widget>[
                        Icon(
                          Icons.delete_forever,
                          color: whiteCOLOR,
                        ),
                        Padding(padding: EdgeInsets.symmetric(horizontal: 10)),
                        Text('Delete',
                            style:
                                TextStyle(color: whiteTextCOLOR, fontSize: 12))
                      ]))))
    ]);
  }
}

Answer 1

根据您的评论，尝试以下操作：

var query = Firestore.instance
                     .collection('users')
                     .document(userDocSTRING.toString())
                     .collection(userCatSTRING.toString())
                     .where('Name', isEqualTo: _selectedCATEGORY);

var category = (await query.getDocuments()).documents[0].documentID;

但是由于这很复杂，所以我考虑使用类别名称作为其ID。因此，您将使用“电子邮件”作为类别“电子邮件”的ID，而不是随机ID。