本文介绍了Flutter TreeView Json数据解析的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想在我的flutter应用程序中使用这个flutter treeview小部件来建立公司的treeview
https://pub.dev/packages/tree_view
我有一个Web服务，其中以树状结构列出了公司列表. https://washservice.com/api/companyXML/1fe5bae2-331a- 4080-b34f-5ebd3518efd8我已经编写了具有递归功能的json解析代码以构建treeview，但无法正常工作.有人可以帮助我解决解析问题并构建treeview小部件
这是我的代码
import 'dart:async';
import 'dart:convert';
import 'package:example/models/Company.dart';
import 'package:example/widgets/directory_widget.dart';
import 'package:example/widgets/file_widget.dart';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:tree_view/tree_view.dart';
class CompaniesPage extends StatefulWidget {
CompaniesPage({Key key, this.title}) : super(key: key);
final String title;
@override
_CompaniesPageState createState() => _CompaniesPageState();
}
class _CompaniesPageState extends State<CompaniesPage> {
List<Company> companiesList = new List<Company>();
@override
void initState() {
super.initState();
// Loading initial data or first request to get the data
_getTeeViewData1();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title ?? 'Tree View demo'),
),
body: Center(
child: TreeView(
startExpanded: false,
children: _getChildList(companiesList),
),
),
);
}
// Webservice request to load 20 users data using paging
Future<List<Company>> _getTeeViewData1() async {
String url =
"https://washservice.com/api/companyXML/1fe5bae2-331a-4080-b34f-5ebd3518efd8";
print(url);
var response = await http.get(url);
var jsonData = json.decode(response.body);
print(jsonData);
var data = jsonData["Companies"];
var companies = data["Company"];
print(companies);
Company c = new Company();
c.CompanyId = companies["CompanyId"];
c.CompanyName = companies["CompanyName"];
c.ParentId = companies["ParentId"];
c.CostCenter = '${companies["CostCenter"] ?? ""}';
c.IsSelectableforMovement = companies["IsSelectableforMovement"];
c = getChildCompanies(companies["Company"], c);
companiesList.add(c);
return companiesList;
}
Company getChildCompanies(childCompanies, parentCompany) {
if (childCompanies != null) {
for (var childCompany in childCompanies) {
Company childCO = new Company();
childCO.CompanyId = childCompany["CompanyId"];
childCO.CompanyName = childCompany["CompanyName"];
childCO.ParentId = childCompany["ParentId"];
childCO.CostCenter = '${childCompany["CostCenter"] ?? ""}';
childCO.IsSelectableforMovement =
childCompany["IsSelectableforMovement"];
Company c2 = getChildCompanies(childCompany["Company"], childCO);
parentCompany.company.add(c2);
return parentCompany;
}
}
}
List<Widget> _getChildList(List<Company> childDocuments) {
return childDocuments.map((document) {
if (document.company.length != 0) {
return Container(
margin: EdgeInsets.only(left: 8),
child: TreeViewChild(
parent: _getDocumentWidget(document: document),
children: _getChildList(document.company),
),
);
}
return Container(
margin: const EdgeInsets.only(left: 4.0),
child: _getDocumentWidget(document: document),
);
}).toList();
}
Widget _getDocumentWidget({@required Company document}) =>
document.company.length == 0
? _getFileWidget(document: document)
: _getDirectoryWidget(document: document);
DirectoryWidget _getDirectoryWidget({@required Company document}) =>
DirectoryWidget(directoryName: document.CompanyName);
FileWidget _getFileWidget({@required Company document}) =>
FileWidget(fileName: document.CompanyName);
}
Company.dart
class Company {
Company();
String CompanyId;
String CompanyName;
String ParentId;
String CostCenter;
String IsSelectableforMovement;
List<Company> company = new List<Company>();
}
解决方案
我对自己的json数据使用了相同的包.在这里您可以找到用法示例.也许您可以对其进行调整以供使用.
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:tree_view/tree_view.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'title',
theme: ThemeData(
primarySwatch: Colors.blue,
),
initialRoute: '/',
routes: {
'/': (context) => TestPage(),
},
);
}
}
class TestPage extends StatefulWidget {
@override
_TestPageState createState() => _TestPageState();
}
class _TestPageState extends State<TestPage> {
String responseBody =
'{ "id": 0,"name": "A","children": [{ "id": 1, "name": "Aa","children": [{"id": 2,"name": "Aa1","children": null}]},{ "id": 3, "name": "Ab","children": [{"id": 4,"name": "Ab1","children": null},{"id": 5,"name": "Ab2","children": null}]}]}';
@override
Widget build(BuildContext context) {
Map mapBody = jsonDecode(responseBody);
return SafeArea(
child: Scaffold(
body: printGroupTree(
mapBody,
),
),
);
}
Widget printGroupTree(
Map group, {
double level = 0,
}) {
if (group['children'] != null) {
List<Widget> subGroups = List<Widget>();
for (Map subGroup in group['children']) {
subGroups.add(
printGroupTree(
subGroup,
level: level + 1,
),
);
}
return Parent(
parent: _card(
group['name'],
level * 20,
),
childList: ChildList(
children: subGroups,
),
);
} else {
return _card(
group['name'],
level * 20,
);
}
}
Widget _card(
String groupName,
double leftPadding,
) {
return Container(
padding: EdgeInsets.only(
left: leftPadding + 5,
right: 20,
),
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(50.0),
),
height: 100,
child: Row(
children: <Widget>[
Container(
width: 250,
child: Row(
children: <Widget>[
Container(
height: 70,
width: 70,
decoration: BoxDecoration(
shape: BoxShape.rectangle,
image: DecorationImage(
fit: BoxFit.fill,
image: NetworkImage(
'https://upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Rubik%27s_cube.svg/220px-Rubik%27s_cube.svg.png',
),
),
),
),
SizedBox(
width: 10,
),
Flexible(
child: Text(
'SomeText',
),
),
],
),
),
Expanded(
child: SizedBox(),
),
InkWell(
//TODO:Empty method here
onTap: () {},
child: Icon(
Icons.group_add,
size: 40,
),
)
],
),
);
}
}
I want to use this flutter treeview widget in my flutter app to build companies treeview
https://pub.dev/packages/tree_view
i have a webservice with list of companies in a tree structure.https://washservice.com/api/companyXML/1fe5bae2-331a-4080-b34f-5ebd3518efd8
I have written json parsing code with recursive function to build treeview but it is not working .can someone help me to fix parsing issue and build treeview widget
Here is my code
import 'dart:async';
import 'dart:convert';
import 'package:example/models/Company.dart';
import 'package:example/widgets/directory_widget.dart';
import 'package:example/widgets/file_widget.dart';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:tree_view/tree_view.dart';
class CompaniesPage extends StatefulWidget {
CompaniesPage({Key key, this.title}) : super(key: key);
final String title;
@override
_CompaniesPageState createState() => _CompaniesPageState();
}
class _CompaniesPageState extends State<CompaniesPage> {
List<Company> companiesList = new List<Company>();
@override
void initState() {
super.initState();
// Loading initial data or first request to get the data
_getTeeViewData1();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title ?? 'Tree View demo'),
),
body: Center(
child: TreeView(
startExpanded: false,
children: _getChildList(companiesList),
),
),
);
}
// Webservice request to load 20 users data using paging
Future<List<Company>> _getTeeViewData1() async {
String url =
"https://washservice.com/api/companyXML/1fe5bae2-331a-4080-b34f-5ebd3518efd8";
print(url);
var response = await http.get(url);
var jsonData = json.decode(response.body);
print(jsonData);
var data = jsonData["Companies"];
var companies = data["Company"];
print(companies);
Company c = new Company();
c.CompanyId = companies["CompanyId"];
c.CompanyName = companies["CompanyName"];
c.ParentId = companies["ParentId"];
c.CostCenter = '${companies["CostCenter"] ?? ""}';
c.IsSelectableforMovement = companies["IsSelectableforMovement"];
c = getChildCompanies(companies["Company"], c);
companiesList.add(c);
return companiesList;
}
Company getChildCompanies(childCompanies, parentCompany) {
if (childCompanies != null) {
for (var childCompany in childCompanies) {
Company childCO = new Company();
childCO.CompanyId = childCompany["CompanyId"];
childCO.CompanyName = childCompany["CompanyName"];
childCO.ParentId = childCompany["ParentId"];
childCO.CostCenter = '${childCompany["CostCenter"] ?? ""}';
childCO.IsSelectableforMovement =
childCompany["IsSelectableforMovement"];
Company c2 = getChildCompanies(childCompany["Company"], childCO);
parentCompany.company.add(c2);
return parentCompany;
}
}
}
List<Widget> _getChildList(List<Company> childDocuments) {
return childDocuments.map((document) {
if (document.company.length != 0) {
return Container(
margin: EdgeInsets.only(left: 8),
child: TreeViewChild(
parent: _getDocumentWidget(document: document),
children: _getChildList(document.company),
),
);
}
return Container(
margin: const EdgeInsets.only(left: 4.0),
child: _getDocumentWidget(document: document),
);
}).toList();
}
Widget _getDocumentWidget({@required Company document}) =>
document.company.length == 0
? _getFileWidget(document: document)
: _getDirectoryWidget(document: document);
DirectoryWidget _getDirectoryWidget({@required Company document}) =>
DirectoryWidget(directoryName: document.CompanyName);
FileWidget _getFileWidget({@required Company document}) =>
FileWidget(fileName: document.CompanyName);
}
Company.dart
class Company {
Company();
String CompanyId;
String CompanyName;
String ParentId;
String CostCenter;
String IsSelectableforMovement;
List<Company> company = new List<Company>();
}
解决方案
I used the same package with my own json data. Here you can find a sample of usage. Maybe you can adapt it for your use.
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:tree_view/tree_view.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'title',
theme: ThemeData(
primarySwatch: Colors.blue,
),
initialRoute: '/',
routes: {
'/': (context) => TestPage(),
},
);
}
}
class TestPage extends StatefulWidget {
@override
_TestPageState createState() => _TestPageState();
}
class _TestPageState extends State<TestPage> {
String responseBody =
'{ "id": 0,"name": "A","children": [{ "id": 1, "name": "Aa","children": [{"id": 2,"name": "Aa1","children": null}]},{ "id": 3, "name": "Ab","children": [{"id": 4,"name": "Ab1","children": null},{"id": 5,"name": "Ab2","children": null}]}]}';
@override
Widget build(BuildContext context) {
Map mapBody = jsonDecode(responseBody);
return SafeArea(
child: Scaffold(
body: printGroupTree(
mapBody,
),
),
);
}
Widget printGroupTree(
Map group, {
double level = 0,
}) {
if (group['children'] != null) {
List<Widget> subGroups = List<Widget>();
for (Map subGroup in group['children']) {
subGroups.add(
printGroupTree(
subGroup,
level: level + 1,
),
);
}
return Parent(
parent: _card(
group['name'],
level * 20,
),
childList: ChildList(
children: subGroups,
),
);
} else {
return _card(
group['name'],
level * 20,
);
}
}
Widget _card(
String groupName,
double leftPadding,
) {
return Container(
padding: EdgeInsets.only(
left: leftPadding + 5,
right: 20,
),
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(50.0),
),
height: 100,
child: Row(
children: <Widget>[
Container(
width: 250,
child: Row(
children: <Widget>[
Container(
height: 70,
width: 70,
decoration: BoxDecoration(
shape: BoxShape.rectangle,
image: DecorationImage(
fit: BoxFit.fill,
image: NetworkImage(
'https://upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Rubik%27s_cube.svg/220px-Rubik%27s_cube.svg.png',
),
),
),
),
SizedBox(
width: 10,
),
Flexible(
child: Text(
'SomeText',
),
),
],
),
),
Expanded(
child: SizedBox(),
),
InkWell(
//TODO:Empty method here
onTap: () {},
child: Icon(
Icons.group_add,
size: 40,
),
)
],
),
);
}
}
这篇关于Flutter TreeView Json数据解析的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！