import 'dart:math' as math;
import 'package:flutter/widgets.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/gestures.dart' show DragStartBehavior;
import 'button_bar.dart';
import 'card.dart';
import 'constants.dart';
import 'data_table.dart';
import 'data_table_source.dart';
import 'debug.dart';
import 'dropdown.dart';
import 'icon_button.dart';
import 'icons.dart';
import 'ink_decoration.dart';
import 'material_localizations.dart';
import 'progress_indicator.dart';
import 'theme.dart';


class paginatedDataTable extends StatefulWidget {

  paginatedDataTable({
    Key key,this.header,this.actions,@required this.columns,this.sortColumnIndex,this.sortAscending = true,this.onSelectAll,this.dataRowHeight = kMinInteractiveDimension,this.headingRowHeight = 56.0,this.horizontalMargin = 24.0,this.columnSpacing = 56.0,this.initialFirstRowIndex = 0,this.onPageChanged,this.rowsPerPage = defaultRowsPerPage,this.availableRowsPerPage = const <int>[defaultRowsPerPage,defaultRowsPerPage * 2,defaultRowsPerPage * 5,defaultRowsPerPage * 10],this.onRowsPerPageChanged,this.dragStartBehavior = DragStartBehavior.start,@required this.source,}) : assert(header == null),assert(columns != null),assert(dragStartBehavior != null),assert(columns.isnotEmpty),assert(sortColumnIndex == null || (sortColumnIndex >= 0 && sortColumnIndex < columns.length)),assert(sortAscending != null),assert(dataRowHeight != null),assert(headingRowHeight != null),assert(horizontalMargin != null),assert(columnSpacing != null),assert(rowsPerPage != null),assert(rowsPerPage > 0),assert(() {
         if (onRowsPerPageChanged != null)
           assert(availableRowsPerPage != null && availableRowsPerPage.contains(rowsPerPage));
         return true;
       }()),assert(source != null),super(key: key);


  final Widget header; 
  final List<Widget> actions;
  final List<DataColumn> columns;
  final int sortColumnIndex;
  final bool sortAscending;
  final ValueSetter<bool> onSelectAll;
  final double dataRowHeight;
  final double headingRowHeight;
  final double horizontalMargin;
  final double columnSpacing;
  final int initialFirstRowIndex;
  final ValueChanged<int> onPageChanged;
  final int rowsPerPage;

  static const int defaultRowsPerPage = 10;
  final List<int> availableRowsPerPage;
  final ValueChanged<int> onRowsPerPageChanged;
  final DataTableSource source;
  final DragStartBehavior dragStartBehavior;
  @override
  paginatedDataTableState createState() => paginatedDataTableState();
}

class paginatedDataTableState extends State<paginatedDataTable> {
  int _firstRowIndex;
  int _rowCount;
  bool _rowCountApproximate;
  int _selectedRowCount;
  final Map<int,DataRow> _rows = <int,DataRow>{};

  @override
  void initState() {
    super.initState();
    _firstRowIndex = PageStorage.of(context)?.readState(context) ?? widget.initialFirstRowIndex ?? 0;
    widget.source.addListener(_handleDataSourceChanged);
    _handleDataSourceChanged();
  }

  @override
  void didUpdateWidget(paginatedDataTable oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (oldWidget.source != widget.source) {
      oldWidget.source.removeListener(_handleDataSourceChanged);
      widget.source.addListener(_handleDataSourceChanged);
      _handleDataSourceChanged();
    }
  }

  @override
  void dispose() {
    widget.source.removeListener(_handleDataSourceChanged);
    super.dispose();
  }

  void _handleDataSourceChanged() {
    setState(() {
      _rowCount = widget.source.rowCount;
      _rowCountApproximate = widget.source.isRowCountApproximate;
      _selectedRowCount = widget.source.selectedRowCount;
      _rows.clear();
    });
  }

  /// Ensures that the given row is visible.
  void pageTo(int rowIndex) {
    final int oldFirstRowIndex = _firstRowIndex;
    setState(() {
      final int rowsPerPage = widget.rowsPerPage;
      _firstRowIndex = (rowIndex ~/ rowsPerPage) * rowsPerPage;
    });
    if ((widget.onPageChanged != null) &&
        (oldFirstRowIndex != _firstRowIndex))
      widget.onPageChanged(_firstRowIndex);
  }

  DataRow _getBlankRowFor(int index) {
    return DataRow.byIndex(
      index: index,cells: widget.columns.map<DataCell>((DataColumn column) => DataCell.empty).toList(),);
  }

  DataRow _getProgressIndicatorRowFor(int index) {
    bool haveProgressIndicator = false;
    final List<DataCell> cells = widget.columns.map<DataCell>((DataColumn column) {
      if (!column.numeric) {
        haveProgressIndicator = true;
        return const DataCell(CircularProgressIndicator());
      }
      return DataCell.empty;
    }).toList();
    if (!haveProgressIndicator) {
      haveProgressIndicator = true;
      cells[0] = const DataCell(CircularProgressIndicator());
    }
    return DataRow.byIndex(
      index: index,cells: cells,);
  }

  List<DataRow> _getRows(int firstRowIndex,int rowsPerPage) {
    final List<DataRow> result = <DataRow>[];
    final int nextPageFirstRowIndex = firstRowIndex + rowsPerPage;
    bool haveProgressIndicator = false;
    for (int index = firstRowIndex; index < nextPageFirstRowIndex; index += 1) {
      DataRow row;
      if (index < _rowCount || _rowCountApproximate) {
        row = _rows.putIfAbsent(index,() => widget.source.getRow(index));
        if (row == null && !haveProgressIndicator) {
          row ??= _getProgressIndicatorRowFor(index);
          haveProgressIndicator = true;
        }
      }
      row ??= _getBlankRowFor(index);
      result.add(row);
    }
    return result;
  }

  void _handlePrevious() {
    pageTo(math.max(_firstRowIndex - widget.rowsPerPage,0));
  }

  void _handleNext() {
    pageTo(_firstRowIndex + widget.rowsPerPage);
  }

  final GlobalKey _tableKey = GlobalKey();

  @override
  Widget build(BuildContext context) {

    assert(debugCheckHasMaterialLocalizations(context));
    final ThemeData themeData = Theme.of(context);
    final MaterialLocalizations localizations = MaterialLocalizations.of(context);
    // HEADER
    final List<Widget> headerWidgets = <Widget>[];
    double startPadding = 24.0;
    if (_selectedRowCount == 0) {
      // headerWidgets.add(Expanded(child: widget.header));
      if (widget.header is ButtonBar) {

        startPadding = 12.0;
      }
    } else {
      headerWidgets.add(Expanded(
        child: Text(localizations.selectedRowCountTitle(_selectedRowCount)),));
    }
    if (widget.actions != null) {
      headerWidgets.addAll(
        widget.actions.map<Widget>((Widget action) {
          return Padding(
            // 8.0 is the default padding of an icon button
            padding: const EdgeInsetsDirectional.only(start: 24.0 - 8.0 * 2.0),child: action,);
        }).toList()
      );
    }

    // FOOTER
    final TextStyle footerTextStyle = themeData.textTheme.caption;
    final List<Widget> footerWidgets = <Widget>[];
    if (widget.onRowsPerPageChanged != null) {
      final List<Widget> availableRowsPerPage = widget.availableRowsPerPage
        .where((int value) => value <= _rowCount || value == widget.rowsPerPage)
        .map<DropdownmenuItem<int>>((int value) {
          return DropdownmenuItem<int>(
            value: value,child: Text('$value'),);
        })
        .toList();
      footerWidgets.addAll(<Widget>[
        Container(width: 14.0),// to match trailing padding in case we overflow and end up scrolling
        Text(localizations.rowsPerPageTitle),ConstrainedBox(
          constraints: const BoxConstraints(minWidth: 64.0),// 40.0 for the text,24.0 for the icon
          child: Align(
            alignment: AlignmentDirectional.centerEnd,child: DropdownButtonHideUnderline(
              child: DropdownButton<int>(
                items: availableRowsPerPage,value: widget.rowsPerPage,onChanged: widget.onRowsPerPageChanged,style: footerTextStyle,iconSize: 24.0,),]);
    }
    footerWidgets.addAll(<Widget>[
      Container(width: 32.0),Text(
        localizations.pageRowsInfoTitle(
          _firstRowIndex + 1,_firstRowIndex + widget.rowsPerPage,_rowCount,_rowCountApproximate,Container(width: 32.0),IconButton(
        icon: const Icon(Icons.chevron_left),padding: EdgeInsets.zero,tooltip: localizations.previousPageTooltip,onpressed: _firstRowIndex <= 0 ? null : _handlePrevious,Container(width: 24.0),IconButton(
        icon: const Icon(Icons.chevron_right),tooltip: localizations.nextPageTooltip,onpressed: (!_rowCountApproximate && (_firstRowIndex + widget.rowsPerPage >= _rowCount)) ? null : _handleNext,Container(width: 14.0),]);

    // CARD
    return Card(
      semanticContainer: false,child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,children: <Widget>[
          Semantics(
            container: true,child: DefaultTextStyle(

              style: _selectedRowCount > 0 ? themeData.textTheme.subhead.copyWith(color: themeData.accentColor)
                                           : themeData.textTheme.title.copyWith(fontWeight: FontWeight.w400),child: IconTheme.merge(
                data: const IconThemeData(
                  opacity: 0.54
                ),child: Ink(
                  height: 0.0,color: _selectedRowCount > 0 ? themeData.secondaryHeaderColor : null,child: Padding(
                    padding: EdgeInsetsDirectional.only(start: startPadding,end: 0.0),child: Row(
                      mainAxisAlignment: MainAxisAlignment.end,children: headerWidgets,SingleChildScrollView(
            scrollDirection: Axis.horizontal,dragStartBehavior: widget.dragStartBehavior,child: DataTable(
              key: _tableKey,columns: widget.columns,sortColumnIndex: widget.sortColumnIndex,sortAscending: widget.sortAscending,onSelectAll: widget.onSelectAll,dataRowHeight: widget.dataRowHeight,headingRowHeight: widget.headingRowHeight,horizontalMargin: widget.horizontalMargin,columnSpacing: widget.columnSpacing,rows: _getRows(_firstRowIndex,widget.rowsPerPage),DefaultTextStyle(
            style: footerTextStyle,child: IconTheme.merge(
              data: const IconThemeData(
                opacity: 0.54
              ),child: Container(
                height: 56.0,child: SingleChildScrollView(
                  dragStartBehavior: widget.dragStartBehavior,scrollDirection: Axis.horizontal,reverse: true,child: Row(
                    children: footerWidgets,],);
  }
}

它的工作原理，将其替换在paginated_data_table.dart中。 Flutter标头变为Null，现在您可以在模拟器中提供空白，对我来说它的工作。然后，如果我们可以将标题保留在您的flutter应用程序中，则可以编辑代码。您可以参考https://flutter.dev/，在flutter中还有另一个Refer链接，以查看关于flutter paginatedatatable https://pub.dev/documentation/flutter_for_web/latest/material/PaginatedDataTable-class.html