使用 DataTable Flutter 的搜索栏布局

Question

我为我的DataTable 列表创建了一个简单的搜索栏，但问题是我不能只返回我搜索的项目，而是得到空字段和我搜索的项目。我尝试了各种方法，但我得到的错误是我需要行和列一样多，所以这是目前我让它工作的唯一方法。

但我想让它变成这样：

代码如下：

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'models/vehicle.dart';
import 'services/vehicle_api.dart';
import 'models/vehicle_data_provider.dart';

class VehicleList extends StatefulWidget {
  @override
  _VehicleList createState() => _VehicleList();
}

class _VehicleList extends State<VehicleList> {
  TextEditingController controller = TextEditingController();
  String _searchResult = '';

  _getPosts() async {
    HomePageProvider provider =
        Provider.of<HomePageProvider>(context, listen: false);

    var postsResponse = await fetchVehicles();
    if (postsResponse.isSuccessful) {
      provider.setPostsList(postsResponse.data, notify: false);
    } else {
      provider.mergePostsList(
        postsResponse.data,
      );
    }

    provider.setIsHomePageProcessing(false);
  }

  @override
  void initState() {
    _getPosts();
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Card(
          child: new ListTile(
            leading: new Icon(Icons.search),
            title: new TextField(
                controller: controller,
                decoration: new InputDecoration(
                    hintText: 'Search', border: InputBorder.none),
                onChanged: (value) {
                  setState(() {
                    _searchResult = value;
                  });
                }),
            trailing: new IconButton(
              icon: new Icon(Icons.cancel),
              onPressed: () {
                setState(() {
                  controller.clear();
                  _searchResult = '';
                });
              },
            ),
          ),
        ),
        Consumer<HomePageProvider>(
          builder: (context, vehicleData, child) {
            return Column(
              crossAxisAlignment: CrossAxisAlignment.center,
              mainAxisAlignment: MainAxisAlignment.spaceAround,
              children: [
                Container(
                  decoration: BoxDecoration(
                    color: Colors.grey[300],
                    borderRadius: BorderRadius.all(
                      Radius.circular(12.0),
                    ),
                  ),
                  child: SingleChildScrollView(
                    child: DataTable(
                      columnSpacing: 30,
                      columns: <DataColumn>[
                        DataColumn(
                          numeric: false,
                          label: Text(
                            'Friendly Name',
                            style: TextStyle(fontStyle: FontStyle.italic),
                          ),
                        ),
                        DataColumn(
                          label: Text(
                            'Licence Plate',
                            style: TextStyle(fontStyle: FontStyle.italic),
                          ),
                        ),
                        DataColumn(
                          label: Text(
                            'Delete',
                            style: TextStyle(fontStyle: FontStyle.italic),
                          ),
                        ),
                      ],
                      rows: List.generate(
                        vehicleData.postsList.length,
                        (index) {
                          VehicleData post = vehicleData.getPostByIndex(index);
                          return post.licencePlate
                                      .toLowerCase()
                                      .contains(_searchResult) ||
                                  '${post.model}'
                                      .toLowerCase()
                                      .contains(_searchResult) ||
                                  '${post.make}'
                                      .toLowerCase()
                                      .contains(_searchResult) ||
                                  post.type
                                      .toLowerCase()
                                      .contains(_searchResult)
                              ? DataRow(
                                  cells: <DataCell>[
                                    DataCell(
                                      Text('${post.friendlyName}'),
                                    ),
                                    DataCell(
                                      Text('${post.licencePlate}'),
                                    ),
                                    DataCell(
                                      IconButton(
                                        icon: Icon(Icons.delete),
                                        onPressed: () {
                                          vehicleData.deletePost(post);
                                        },
                                      ),
                                    ),
                                  ],
                                )
                              : DataRow(
/// This is the part where I return empty rows with one row with the search bar results, so I assume this must me changed
                                  cells: <DataCell>[
                                    DataCell(Text('')),
                                    DataCell(Text('')),
                                    DataCell(Text('')),
                                  ],
                                );
                        },
                      ),
                    ),
                  ),
                ),
              ],
            );
          },
        ),
      ],
    );
  }
}

似乎无法弄清楚这一点。提前感谢您的帮助！

Answer 1

好的，在你发表评论后，我终于让它像我认为你想要的那样工作。这个想法是使用两个列表而不是一个列表，并且由于该空行而不使用 List.generate 方法。当您更改 _searchResult 值时，您会使用来自 users 列表的原始值过滤 userFiltered 列表。

我在 DataTable 中使用了 Flutter 示例并进行了这些编辑，它可以正常工作：

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

/// This is the main application widget.
class MyApp extends StatelessWidget {
  const MyApp({Key key}) : super(key: key);

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: MyStatelessWidget(),
      ),
    );
  }
}


class User{
  String name;
  int age;
  String role;

  User({this.name, this.age, this.role});
}

/// This is the stateless widget that the main application instantiates.
class MyStatelessWidget extends StatefulWidget {
  MyStatelessWidget({Key key}) : super(key: key);

  @override
  _MyStatelessWidgetState createState() => _MyStatelessWidgetState();
}

class _MyStatelessWidgetState extends State<MyStatelessWidget> {
  List<User> users = [User(name: "Sarah", age: 19, role: "Student"), User(name: "Janine", age: 43, role: "Professor")];
  List<User> usersFiltered = [];
  TextEditingController controller = TextEditingController();
  String _searchResult = '';

  @override
  void initState() {
    super.initState();
    usersFiltered = users;
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Card(
          child: new ListTile(
            leading: new Icon(Icons.search),
            title: new TextField(
                controller: controller,
                decoration: new InputDecoration(
                    hintText: 'Search', border: InputBorder.none),
                onChanged: (value) {
                  setState(() {
                    _searchResult = value;
                     usersFiltered = users.where((user) => user.name.contains(_searchResult) || user.role.contains(_searchResult)).toList();
                  });
                }),
            trailing: new IconButton(
              icon: new Icon(Icons.cancel),
              onPressed: () {
                setState(() {
                  controller.clear();
                  _searchResult = '';
                  usersFiltered = users;
                });
              },
            ),
          ),
        ),
        DataTable(
          columns: const <DataColumn>[
            DataColumn(
              label: Text(
                'Name',
                style: TextStyle(fontStyle: FontStyle.italic),
              ),
            ),
            DataColumn(
              label: Text(
                'Age',
                style: TextStyle(fontStyle: FontStyle.italic),
              ),
            ),
            DataColumn(
              label: Text(
                'Role',
                style: TextStyle(fontStyle: FontStyle.italic),
              ),
            ),
          ],
          rows: List.generate(usersFiltered.length, (index) =>
              DataRow(
                cells: <DataCell>[
                  DataCell(Text(usersFiltered[index].name)),
                  DataCell(Text(usersFiltered[index].age.toString())),
                  DataCell(Text(usersFiltered[index].role)),
                ],
              ),
          ),
        ),
      ],
    );
  }
}

旧帖：

我正在寻找一种过滤数据表的方法，您的问题解决了我的问题，谢谢（我现在会尽力帮助您！）。通过使用 PaginatedDataTable 小部件而不是 DataTable 我可以实现您想要的结果。这个想法是在将列表传递给源属性之前对其进行过滤。这是我用来过滤列表的代码的一部分。在 switch 块内我过滤它以删除其他元素：

switch(filter){
        case "Id d'expédition":
          expeditionsList = expeditionsList.where((e) => e.expeditionId.toLowerCase() == stringToSearch.toLowerCase()).toList();
          break;
      }

return PaginatedDataTable(
      showCheckboxColumn: false,
      rowsPerPage: 5,
      source: DataTableSourceExpedition(
          expeditions: expeditionsList,
          onRowClicked: (index) async {
            await ExpeditionRowDialog.buildExpeditionRowDialog(
                    context, expeditionsList[index].expeditionsDetails)
                .show();
          },
      header: Container(
        width: 100,
        child: Text("Expéditions"),
      ),
      columns: [
        DataColumn(
            label: Text("Id d'expédition"), numeric: false, tooltip: "id"),
        
      ],
    );

然后我需要使用需要 DataTableSource 对象的源属性将数据传递给表。我创建了一个扩展 DataTableSource 的单独类。我将过滤后的列表作为此类的参数传递，并覆盖 DataTableSource 类的方法：

class DataTableSourceExpedition extends DataTableSource {
    List<Expedition> expeditions = List();
    Function onRowClicked;
    Function onDeleteIconClick;
    final df = DateFormat('dd.MM.yyyy');

   DataTableSourceExpedition({this.expeditions, this.onRowClicked, 
      this.onDeleteIconClick});
       DataRow getRow(int index) {
       final _expedition = expeditions[index];

return DataRow.byIndex(
    index: index,
    cells: <DataCell>[
      DataCell(Text("${_expedition.expeditionId}")),
      DataCell(IconButton(
        icon: Icon(Icons.delete_forever, color: kReturnColor,),
        onPressed: (){onDeleteIconClick(index);},
      ))
    ],
    onSelectChanged: (b) => onRowClicked(index));
  }


  bool get isRowCountApproximate => false;


  int get rowCount => expeditions.length;


  int get selectedRowCount => 0;
}

像这样，我可以在不需要添加空行的情况下过滤唯一的项目，如下图所示：

如果列表为空，它也可以工作。