我正在使用PaginatedDataTable来显示我的数据。数据来自json。我可以显示数据并使用分页。但是排序在我的代码中不起作用。
我使用此代码作为参考。排序在引用中运行良好。但是在这个代码中只有行是动态的。
我动态地接收列和行，不知道如何使用动态数据进行排序。
这是我定义分页数据表的DataGrid：
import 'dart:async';
import 'package:boshloo/Dashboard/ChartInfo.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
class Result {
List<DataCell> cells;
List<DataColumn> columns;
Result({this.cells, this.columns});
bool selected = false;
}
class ResultsDataSource extends DataTableSource {
final List<Result> _results;
ResultsDataSource(this._results);
void _sort<T>(Comparable<T> getField(Result d), bool ascending) {
_results.sort((Result a, Result b) {
if (!ascending) {
final Result c = a;
a = b;
b = c;
}
final Comparable<T> aValue = getField(a);
final Comparable<T> bValue = getField(b);
return Comparable.compare(aValue, bValue);
});
notifyListeners();
}
int _selectedCount = 0;
@override
DataRow getRow(int index) {
assert(index >= 0);
if (index >= _results.length) return null;
final Result result = _results[index];
return DataRow.byIndex(
index: index,
selected: result.selected,
onSelectChanged: (bool value) {
if (result.selected != value) {
_selectedCount += value ? 1 : -1;
assert(_selectedCount >= 0);
result.selected = value;
notifyListeners();
}
},
cells: result.cells);
}
@override
int get rowCount => _results.length;
@override
bool get isRowCountApproximate => false;
@override
int get selectedRowCount => _selectedCount;
void _selectAll(bool checked) {
for (Result result in _results) result.selected = checked;
_selectedCount = checked ? _results.length : 0;
notifyListeners();
}
}
class DataGrid extends StatefulWidget {
final ChartInfo chartsInfo;
ResultsDataSource _resultsDataSource = ResultsDataSource([]);
bool isLoaded = false;
DataGrid({Key key, this.chartsInfo}) : super(key: key);
@override
_DataGridState createState() => _DataGridState();
}
class _DataGridState extends State<DataGrid> {
ResultsDataSource _resultsDataSource = ResultsDataSource([]);
bool isLoaded = false;
int _rowsPerPage = 10;
int _sortColumnIndex;
bool _sortAscending = true;
void _sort<T>(
Comparable<T> getField(Result d), int columnIndex, bool ascending) {
_resultsDataSource._sort<T>(getField, ascending);
setState(() {
_sortColumnIndex = columnIndex;
_sortAscending = ascending;
});
}
Future<void> getData() async {
List<Result> results = List();
for (var i = 0; i < dataRows.length; i++) {
results.add(Result(
cells: dataRows[i].cells,
));
}
if (!isLoaded) {
setState(() {
_resultsDataSource = ResultsDataSource(results);
isLoaded = true;
});
}
}
List<DataColumn> dataColumns = List();
List<DataRow> dataRows = List();
void _setDataColumnsRows() {
//print('widget.chartsInfo.gridData = ' + widget.chartsInfo.gridData[0].values.toList()[0].toString());
for (var i = 0; i < widget.chartsInfo.gridFields.length; i++) {
dataColumns.add(
DataColumn(
label: Text(widget.chartsInfo.gridFields.keys.toList()[i]),
//numeric: false,
onSort: (int columnIndex, bool ascending) {
_sort<String>((Result d) {
return widget.chartsInfo.gridFields.keys.toList()[i];
}, columnIndex, ascending);
},
),
);
}
//print('DataCoumns length = ' + dataColumns.length.toString());
for (var i = 0; i < widget.chartsInfo.gridData.length; i++) {
List<DataCell> cells = List();
//print('DataRow[ ');
for (var j = 0; j < widget.chartsInfo.gridData[i].length; j++) {
//print('Cell $j = ' + widget.chartsInfo.gridData[i].values.toList()[j].toString());
cells.add(DataCell(
Text(widget.chartsInfo.gridData[i].values.toList()[j].toString())));
}
//print('cells length = ' + cells.length.toString());
dataRows.add(DataRow(cells: cells));
//print(' ]');
}
}
@override
void initState() {
super.initState();
_setDataColumnsRows();
getData();
}
@override
Widget build(BuildContext context) {
return SingleChildScrollView(
scrollDirection: Axis.horizontal,
child: Container(
width: MediaQuery.of(context).size.width,
child: PaginatedDataTable(
header: Text(widget.chartsInfo.title),
rowsPerPage: _rowsPerPage,
onRowsPerPageChanged: (int value) {
setState(() {
_rowsPerPage = value;
});
},
sortColumnIndex: _sortColumnIndex,
sortAscending: _sortAscending,
onSelectAll: _resultsDataSource._selectAll,
columns: dataColumns,
source: _resultsDataSource),
),
);
}
}
这是我接收json并显示DataGrid:的Dashboard
import 'dart:convert';
import 'package:boshloo/Dashboard/ChartInfo.dart';
import 'package:flutter/material.dart';
import 'BarChart.dart';
import 'DataGrid.dart';
import 'GaugeChart.dart';
import 'LineChart.dart';
import 'PieChart.dart';
import 'package:http/http.dart' as http;
class Dashboard extends StatefulWidget {
@override
_DashboardState createState() => _DashboardState();
}
class _DashboardState extends State<Dashboard> {
List<ChartInfo> charts = List();
bool isLoaded = false;
@override
void initState() {
super.initState();
_getCharts().then((ch) {
setState(() {
charts = ch;
isLoaded = true;
});
});
}
Future<List<ChartInfo>> _getCharts() async {
List<ChartInfo> charts = List();
String url =
'http://ls.arian.co.ir:8081/api/1.0/arian/mobiledashboard/dashlet-list/71';
//print('body = ' + body);
http.Response response = http.Response('{}', 200);
response = await http.get(url);
//print('respons body = ' + response.body);
try {} catch (e) {
print('failed' + e.toString());
return null;
}
List<dynamic> json = jsonDecode(response.body);
for (var i = 0; i < json.length; i++) {
//print('json[i]["domain-title"] = ' + json[i]['domain-title'][0]);
ChartInfo chart;
if (json[i]['title'] == 'تست گرید ') {
chart = ChartInfo(
title: json[i]['title'],
type: 'grid',
domainTitle: json[i]['domain-title'],
measureTitle: json[i]['measure-title'],
measures: json[i]['measure'],
gridFields: json[i]['fields'],
gridData: json[i]['data'],
);
} else {
chart = ChartInfo(
title: json[i]['title'],
type: json[i]['type'],
domainTitle: json[i]['domain-title'],
measureTitle: json[i]['measure-title'],
measures: json[i]['measure'],
);
}
//print('title' + chart.title);
//print('chart measure = ' + chart.measures.values.toList()[0].toString());
charts.add(chart);
//print('measures ' + chart.measures[0][1].toString());
}
return charts;
}
@override
Widget build(BuildContext context) {
List<Widget> _getChartsWidget() {
List<Widget> chartList = List();
for (var i = 0; i < charts.length; i++) {
if (charts[i].type == 'bar' || charts[i].type == 'column') {
//chartList.add(BarChart(chartsInfo: charts[i]));
} else if (charts[i].type == 'pie') {
//chartList.add(PieChart(chartsInfo: charts[i],));
} else if (charts[i].type == 'line') {
//chartList.add(LineChart(chartsInfo: charts[i]));
} else if (charts[i].type == 'grid'){
chartList.add(DataGrid(chartsInfo: charts[i]));
}
}
chartList.add(GaugeChart());
return chartList;
}
return Scaffold(
body: isLoaded
? Container(
child: ListView(
children: _getChartsWidget(),
),
)
: Container(),
);
}
}
Json链接(数组中的第三个(索引#2((是需要在表中显示的数据。
"字段"(只有键，值没有用(是我的列，"数据"是我的行
(我认为您不需要我包含的json文件(。
如有任何帮助，我们将不胜感激。
即使List有动态数据，也可能有重复出现的属性。为了包括带有"；"空"；值，您可以在List.sort中处理null。通过这种方法，具有null属性值的行将包含在List中。