Flutter：如何向 ListView 添加标题行

Question

对 Flutter 非常陌生。我已经能够利用 HTTP 数据请求、构建

ListView

、编辑该列表中的行以及其他基础知识。环境优美。

我已经设法为

ListView

拼凑出一个结构糟糕的标题，但我知道这是不对的。我无法让标题文本正确排列。

我看到

Drawer

类有一个

DrawerHeader

类，但看不到

ListView

有一个

ListViewHeader

。

@override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text('Contacts'),
          actions: <Widget>[
            IconButton(icon: Icon(Icons.add_circle),
                onPressed: getCustData
            ),
          ],
        ),
        //body:
        body: Column(
            children: <Widget>[
              Row(
                  children: <Widget>[
                    Expanded(child: Text('', style: TextStyle(height: 3.0, fontSize: 15.2, fontWeight: FontWeight.bold,))),
                    Expanded(child: Text('First Name', style:  TextStyle(height: 3.0, fontSize: 15.2, fontWeight: FontWeight.bold,))),
                    Expanded(child: Text('Last Name', style:  TextStyle(height: 3.0, fontSize: 15.2, fontWeight: FontWeight.bold,))),
                    Expanded(child: Text('City', style: TextStyle(height: 3.0, fontSize: 15.2, fontWeight: FontWeight.bold,))),
                    Expanded(child: Text('Customer Id', style: TextStyle(height: 3.0, fontSize: 15.2, fontWeight: FontWeight.bold,))),
                    Expanded(child: Text('', style: TextStyle(height: 3.0, fontSize: 15.2, fontWeight: FontWeight.bold,))),
                  ]
              ),

              Expanded(child:Container(
                child: ListView.builder(

                  itemCount: data == null ? 0 : data.length,
                  itemBuilder: (BuildContext context, int index) {

                    return InkWell(
                      onTap: () {
                        Navigator.push(
                          context,
                          MaterialPageRoute(
                              builder: (context) => APIDetailView(data[index])),
                        );
                      },

                      child: ListTile(                //return new ListTile(
                          onTap: null,
                          leading: CircleAvatar(
                            backgroundColor: Colors.blue,
                            child: Text(data[index]["FirstName"][0]),
                          ),
                          title: Row(
                              children: <Widget>[
                                Expanded(child: Text(data[index]["FirstName"])),
                                Expanded(child: Text(data[index]["LastName"])),
                                Expanded(child: Text(data[index]["Bill_City"])),
                                Expanded(child: Text(data[index]["Customer_Id"])),
                              ]
                          )
                      ),

                    );
                  }, //itemBuilder

                ),
              ),
            ),
          ]
        )
    );
  }
}

谢谢。

Answer 1

通过 itemBuilder 将标题返回为第一行：

ListView.builder(
    itemCount: data == null ? 1 : data.length + 1,
    itemBuilder: (BuildContext context, int index) {
        if (index == 0) {
            // return the header
            return new Column(...);
        }
        index -= 1;

        // return row
        var row = data[index];
        return new InkWell(... with row ...);
    },
);

Answer 2

这就是我解决这个问题的方法。感谢@najeira 让我思考其他解决方案。

在第一个正文列中，我对标题使用了与

ListTile

相同的布局。

因为在本例中，我的数据

ListTil

e 包含

CircleAvatar

，所以所有水平间距都有点偏离...渲染

CircleAvatar

的 5 列...然后是 4 个均匀间隔的列。

所以...我在第一个主体

ListTile

中添加了一个

Column

，一个带有透明的

CircleAvatar

的

backgroundColor

，然后是我的4个标题的

Row

。

        ListTile(
        onTap: null,
        leading: CircleAvatar(
          backgroundColor: Colors.transparent,
        ),
        title: Row(
            children: <Widget>[
              Expanded(child: Text("First Name")),
              Expanded(child: Text("Last Name")),
              Expanded(child: Text("City")),
              Expanded(child: Text("Id")),
            ]
        ),
      ),

Answer 3

您可以在

Container

中添加

ListView

和

Column

。

import 'package:flutter/material.dart';

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

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override
  void initState() {
    // TODO: implement initState
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: Text("Demo App1"),
        ),
        body: Column(
          children: <Widget>[
            Container(
              height: 40.0,
              child: Row(
                children: <Widget>[
                  Container(
                      padding: EdgeInsets.all(4.0),
                      width: 100.0,
                      child: Text(
                        "Name",
                        style: TextStyle(fontSize: 18),
                      )),
                  Container(
                      padding: EdgeInsets.all(4.0),
                      width: 100.0,
                      child: Text(
                        "Age",
                        style: TextStyle(fontSize: 18),
                      )),
                ],
              ),
            ),
            Expanded(
              child: ListView.builder(
                itemCount: 100,
                itemBuilder: (BuildContext context, int index) {
                  return Row(
                    children: <Widget>[
                      Container(
                          padding: EdgeInsets.all(4.0),
                          width: 100.0,
                          child: Text(
                            "Name $index",
                            style: TextStyle(fontSize: 18),
                          )),
                      Container(
                        padding: EdgeInsets.all(4.0),
                        width: 100.0,
                        child: Text(
                          "Age $index",
                          style: TextStyle(fontSize: 18),
                        ),
                      )
                    ],
                  );
                },
              ),
            ),
          ],
        ),
      ),
    );
  }
}

Answer 4

您可以像这样向项目列表中的第一项添加一列

  new ListView.builder(
    itemCount: litems.length,
    itemBuilder: (BuildContext ctxt, int index) {
      if (index == 0) {
        return Column(
          children: <Widget>[
            Header(),
            rowContent(index),
          ],
        );
      } else {
        return rowContent(index);
      }
    },
  )

Answer 5

najeira 的解决方案简单明了，但您可以在不接触索引的情况下获得相同且更灵活的结果。

除了使用 listView，您还可以使用 CustomScrollView & SliverList，其功能与 listView 相同。

   return Scaffold(
      body: CustomScrollView(
        slivers: <Widget>[
          SliverToBoxAdapter(
            // you could add any widget
            child: ListTile(
              leading: CircleAvatar(
                backgroundColor: Colors.transparent,
              ),
              title: Row(
                children: <Widget>[
                  Expanded(child: Text("First Name")),
                  Expanded(child: Text("Last Name")),
                  Expanded(child: Text("City")),
                  Expanded(child: Text("Id")),
                ],
              ),
            ),
          ),
          SliverList(
            delegate: SliverChildBuilderDelegate(
              (context, index) {
                return InkWell(
                  onTap: () {
                    Navigator.push(
                      context,
                      MaterialPageRoute(
                          builder: (context) => APIDetailView(data[index])),
                    );
                  },
                  child: ListTile(
                    //return  ListTile(
                    leading: CircleAvatar(
                      backgroundColor: Colors.blue,
                      child: Text(data[index]["FirstName"][0]),
                    ),
                    title: Row(
                      children: <Widget>[
                        Expanded(child: Text(data[index]["FirstName"])),
                        Expanded(child: Text(data[index]["LastName"])),
                        Expanded(child: Text(data[index]["Bill_City"])),
                        Expanded(child: Text(data[index]["Customer_Id"])),
                      ],
                    ),
                  ),
                );
              },
              childCount: data == null ? 0 : data.length,
            ),
          ),
        ],
      ),
    );

Answer 6

使用DataTable小部件！
该小部件允许您构建表格。 代码：

DataTable(columns: [], rows: [],)

示例：

  DataTable(
   columns: [
     DataColumn(label: Text('Lang.')),
     DataColumn(label: Text('Year')),
   ],
   rows: [
     DataRow(cells: [DataCell(Text('Dart')), DataCell(Text('2010'))]),
     DataRow(cells: [DataCell(Text('Go')), DataCell(Text('2009'))]),
     DataRow(cells: [DataCell(Text('PHP')), DataCell(Text('1994'))]),
     DataRow(cells: [DataCell(Text('Java')), DataCell(Text('1995'))]),
   ],
)

输出：

您可以通过观看此官方视频或访问flutter.dev了解有关DataTable

的更多信息

Answer 7

看来您真正需要的是 DataTable 小部件而不是 ListView。 它有一个可定制的标题，包括排序选项。

阅读文档，包括 api.flutter.dev 上的一些很棒的示例：数据表类

Answer 8

我创建了

listview_utils

包来减少构建页眉和页脚列表项所需的样板代码。这是使用该包的示例代码：

import 'package:listview_utils/listview_utils.dart';

CustomListView(
  header: Container(
    child: Text('Header'),
  ),
  itemCount: items.length,
  itemBuilder: (BuildContext context, int index, _) {
    return ListTile(
      title: Text(item['title']),
    );
  },
);

免责声明：我是该包的维护者。

Answer 9

我用这个：

body: Column(
      children: [
        Container(
          // The header will be here
        ),
        Expanded(
          // The ListView
          child: ListView.builder(
              itemCount: // The length,
              itemBuilder: (_, index) {
                return //List Item Widget Here
              }),
        ),
      ],

）

Answer 10

根据您的 api 数据查找动态节标题。将此类添加到您的项目中。

class _FlutterSectionListViewState extends State<FlutterSectionListView> {
  /// List of total number of rows and section in each group
  var itemList = [];
  int itemCount = 0;
  int sectionCount = 0;

  @override
  void initState() {
    /// ----#4
    sectionCount = widget.numberOfSection();

    /// ----#5
    itemCount = listItemCount();
    super.initState();
  }

  /// ----#6
  @override
  Widget build(BuildContext context) {
    return ListView.builder(
      itemCount: itemCount,
      itemBuilder: (context, index) {
        return buildItemWidget(index);
      },
      key: widget.key,
    );
  }

  /// Get the total count of items in list(including both row and sections)
  int listItemCount() {
    itemList = [];
    int rowCount = 0;

    for (int i = 0; i < sectionCount; i++) {
      /// Get the number of rows in each section using callback
      int rows = widget.numberOfRowsInSection(i);

      /// Here 1 is added for each section in one group
      rowCount += rows + 1;
      itemList.insert(i, rowCount);
    }
    return rowCount;
  }

  /// ----#7
  /// Get the widget for each item in list
  Widget buildItemWidget(int index) {
    /// ----#8
    IndexPath indexPath = sectionModel(index);

    /// ----#9
    /// If the row number is -1 of any indexPath it will represent a section else row
    if (indexPath.row < 0) {
      /// ----#10
      return widget.sectionWidget != null
          ? widget.sectionWidget!(indexPath.section)
          : SizedBox(
              height: 0,
            );
    } else {
      return widget.rowWidget!(indexPath.section, indexPath.row);
    }
  }

  /// Calculate/Map the indexPath for an item Index
  IndexPath sectionModel(int index) {
    int? row = 0;
    int section = 0;
    for (int i = 0; i < sectionCount; i++) {
      int item = itemList[i];
      if (index < item) {
        row = (index - (i > 0 ? itemList[i - 1] : 0) - 1) as int?;
        section = i;
        break;
      }
    }
    return IndexPath(section: section, row: row!);
  }
}

/// Helper class for indexPath of each item in list
class IndexPath {
  IndexPath({required this.section, required this.row});

  int section = 0;
  int row = 0;
}

根据您的API数据创建您的列表

 List<List<Operator>> ops = [];
        List<String> sections = [];
        if(c.operatorStatuses.value!.availableOperators.length>0){
           ops.add(c.operatorStatuses.value!.availableOperators);
           sections.add("Müsait Operatörler");
        }

         if(c.operatorStatuses.value!.busyOperators.length>0){
           ops.add(c.operatorStatuses.value!.busyOperators);
           sections.add("Meşgul Operatörler");
        }
         if(c.operatorStatuses.value!.breakOperators.length>0){
             ops.add(c.operatorStatuses.value!.breakOperators);
           sections.add("Moladaki Operatörler");
        }
         if(c.operatorStatuses.value!.closedOperators.length>0){
             ops.add(c.operatorStatuses.value!.closedOperators);
           sections.add("Kapalı Operatörler");
        }
       

在用户界面中显示；

   FlutterSectionListView(
          numberOfSection: () => ops.length,
          numberOfRowsInSection: (section) {
            return ops[section].length;
          },
          sectionWidget: (section) {
            if(section<ops.length){
               return Container(
              child: Padding(
                padding: const EdgeInsets.all(8),
                child: Text(sections[section]),
              ),
              color: Colors.grey,
            );
            }else{
              return SizedBox();
            }
           
          },
          rowWidget: (section, row) {

            if(row < ops[section].length){
Operator? op = ops[section][row];
          
          
            return card(op);
            }else{
              return SizedBox();
            }
           
             
          },
        )

感谢[本文][1]。

注意：根据更新的数据，代码块有时会产生错误。 [1]：https://medium.com/@dharmendra_yadav/ios-like-sectioned-listview-widget-in-flutter-7cf9dab2dd1a

Answer 11

这里我创建了 flat_list 小部件，它具有与 React Native 的 FlatList 类似的规格。

FlatList(
+  listHeaderWidget: const Header(),
  data: items.value,
  buildItem: (item, index) {
    var person = items.value[index];

    return ListItemView(person: person);
  },
),

Answer 12

一种选择是使用

bottom

的

AppBar

属性。例如，下面的代码将在两个远端列上方显示两个标题。

bottom: PreferredSize(
        preferredSize: const Size.fromHeight(16),
        child: Row(
          children: const [
            Spacer(),
            Text('Column1', style: TextStyle(fontSize: 8)),
            SizedBox(width: 24),
            Text('Column2', style: TextStyle(fontSize: 8)),
            SizedBox(width: 24),
          ],
        )),