问获取mysql数据库值

EN

import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:syncfusion_flutter_datagrid/datagrid.dart';
import 'package:http/http.dart'as http;

class AllQuestion extends StatefulWidget {
 String fldPaperTypeID;
 AllQuestion({this.fldPaperTypeID});
@override
_AllQuestionState createState() => _AllQuestionState();
}
List<Question> _question;
List<Question> populateData;

QuestionDataSource _questionDataSource = QuestionDataSource();
List<Question> paginatedDataSource = [];

class _AllQuestionState extends State<AllQuestion> {
bool showLoadingIndicator = true;

Future<List> GetAllQuestion() async{

final response = await http.post('http://eduapp.studysmile.lk/getquestion',body: {"fldPaperTypeID":widget.fldPaperTypeID});
return json.decode(response.body);
}
@override
void initState() {
// TODO: implement initState
super.initState();
_question = populateData();
}
@override

Widget build(BuildContext context) {
return Scaffold(
  appBar: AppBar(
    title: Text('Question'),
  ),
  body: LayoutBuilder(
    builder: (context, constraints) {
      return Row(children: [
        Column(
          children: [
            SizedBox(
                height: constraints.maxHeight - 60,
                width: constraints.maxWidth,
                child: buildStack(constraints)),
            Container(
              height: 60,
              width: constraints.maxWidth,
              child: SfDataPager(
                rowsPerPage: 1,
                direction: Axis.horizontal,
                onPageNavigationStart: (int pageIndex) {
                  setState(() {
                    showLoadingIndicator = true;
                  });
                },
                delegate: _questionDataSource,
                onPageNavigationEnd: (int pageIndex) {
                  setState(() {
                    showLoadingIndicator = false;
                  });
                },
              ),
            )
          ],
        ),
      ]);
    },
  ),
);
}

Widget buildDataGrid(BoxConstraints constraint) {
return SfDataGrid(
    source: _questionDataSource,
    columnWidthMode: ColumnWidthMode.fill,
    columns: <GridColumn>[
      GridNumericColumn(mappingName: 'id', headerText: 'ID'),
      GridTextColumn(mappingName: 'name', headerText: 'Name'),
      GridNumericColumn(mappingName: 'salaryS', headerText: 'Salary'),
    ]);
}

Widget buildStack(BoxConstraints constraints) {
List<Widget> _getChildren() {
  final List<Widget> stackChildren = [];
  stackChildren.add(buildDataGrid(constraints));

  if (showLoadingIndicator) {
    stackChildren.add(Container(
      color: Colors.black12,
      width: constraints.maxWidth,
      height: constraints.maxHeight,
      child: Align(
        alignment: Alignment.center,
        child: CircularProgressIndicator(
          strokeWidth: 3,
        ),
      ),
    ));
  }

  return stackChildren;
}

return Stack(
  children: _getChildren(),
);
}
 /*  List<Question> populateData() {
return [
  Question(10001, 'James', 20000),
  Question(10002, 'Kathryn', 30000),
  Question(10001, 'James', 20000),
  Question(10002, 'Kathryn', 30000),
  Question(10001, 'James', 20000),
  Question(10002, 'Kathryn', 30000),
  Question(10001, 'James', 20000),
  Question(10002, 'Kathryn', 30000),
  Question(10001, 'James', 20000),
  Question(10002, 'Kathryn', 30000),
];
}*/
Future<List<Question>> populateData()async{
final response = await http.post('http://eduapp.studysmile.lk/getquestion',body: 
{"fldPaperTypeID":widget.fldPaperTypeID});
List<Question> populateData = json.decode(response.body);
return populateData;


 }
}
/*
 class SendallQuestion extends StatelessWidget {

List list;
SendallQuestion({this.list});
@override
Widget build(BuildContext context) {
return  ListView.builder(
    itemCount: list == null?0:list.length,
    itemBuilder: (ctx,i){
      return Container(
        alignment: Alignment.center,
        margin: EdgeInsets.all(20),
        child: FlatButton(
          child: Align(
              alignment: Alignment(0.2, 0.6),
              child: Text(list[i]['fldQuestion'], style: TextStyle(fontSize: 20.0),)
          ),
          color: Color(0xff7c4dff),
          textColor: Colors.white,
          onPressed: (){

          },


        ),
      );

    }
);
 }
}*/

class Question{

final int fldQuestionID;
final int fldPaperTypeID;
final String fldQuestion;
Question(this.fldPaperTypeID,this.fldQuestion,this.fldQuestionID);
}

class QuestionDataSource extends DataGridSource<Question> {
@override
List<Question> get dataSource => paginatedDataSource;
@override
Object getValue(Question question, String columnName) {
switch (columnName) {
  case 'id':
    return question.fldPaperTypeID;
    break;
  case 'name':
    return question.fldQuestionID;
    break;
  case 'salaryS':
    return question.fldQuestion;
    break;
  default:
    return ' ';
    break;
}
}

@override
int get rowCount => _question.length;

@override
Future<bool> handlePageChange(int oldPageIndex, int newPageIndex,
  int startRowIndex, int rowsPerPage) async {
int endIndex = startRowIndex + rowsPerPage;
if (endIndex > _question.length) {
  endIndex = _question.length - 1;
}

await Future.delayed(Duration(milliseconds: 2000));

paginatedDataSource = List.from(
    _question.getRange(startRowIndex, endIndex).toList(growable: false));
notifyListeners();
return true;
 }
}