flutter创建表格，有全选和分组功能

在Flutter中创建表格可以使用DataTables Widget，它支持全选和分组功能。以下是一个示例代码：

import 'package:flutter/material.dart';

class DataTableExample extends StatefulWidget {
  @override
  _DataTableExampleState createState() => _DataTableExampleState();
}

class _DataTableExampleState extends State<DataTableExample> {
  List<DataRow> _rows = List.generate(
      10,
      (index) => DataRow(cells: [
            DataCell(Text('cell ${index + 1}')),
            DataCell(Text('value ${index + 1}')),
          ]));

  bool _selectAll = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('DataTable Example'),
      ),
      body: SingleChildScrollView(
        scrollDirection: Axis.horizontal,
        child: DataTable(
          sortColumnIndex: 0,
          sortAscending: true,
          columns: [
            DataColumn(label: Text('Cell')),
            DataColumn(label: Text('Value')),
          ],
          rows: _rows,
          onSelectAll: (isSelected) {
            setState(() {
              _selectAll = isSelected;
              _rows = _rows.map((row) => row.copyWith(selected: isSelected)).toList();
            });
          },
        ),
      ),
      bottomNavigationBar: BottomAppBar(
        child: Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            IconButton(
              icon: Icon(_selectAll ? Icons.check_box : Icons.check_box_outline_blank),
              onPressed: () {
                setState(() {
                  _selectAll = !_selectAll;
                  _rows = _rows.map((row) => row.copyWith(selected: _selectAll)).toList();
                });
              },
            ),
            IconButton(
              icon: Icon(Icons.group),
              onPressed: () {
                // TODO: Implement grouping logic
              },
            ),
          ],
        ),
      ),
    );
  }
}

在这个示例中，我们使用`DataTables` Widget创建了一个表格，并且设置了两列`DataColumn`，分别是`Cell`和`Value`。我们通过`List.generate`方法生成了10行数据，并将它们传递给了`DataTable`的`rows`属性。我们还设置了`onSelectAll`回调函数，用于处理全选功能。在底部的`BottomAppBar`中，我们添加了两个按钮，一个用于全选/取消全选，另一个用于分组操作。请注意，分组操作需要实现自定义逻辑。