json - 我尝试使用颤振和json数据从rest api向DropDownButton显示数据，但它没有用
问题描述
我的代码：
import 'package:flutter/material.dart';
import 'package:shaal/module/home.dart';
import 'package:shaal/controlers/databasehelper.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'dart:io';
import 'dart:convert';
import 'package:http/http.dart' as http;
import 'package:multi_image_picker/multi_image_picker.dart';
import 'dart:async';
import 'package:shaal/module/showdata.dart';
class AddData extends StatefulWidget{
AddData({Key key , this.title}) : super(key : key);
final String title;
@override
AddDataState createState() => AddDataState();
}
class AddDataState extends State<AddData> {
List<Asset> images = List<Asset>();
String _error;
DatabaseHelper databaseHelper = new DatabaseHelper();
final TextEditingController _nameController = new TextEditingController();
final TextEditingController _priceController = new TextEditingController();
final TextEditingController _descriptionController = new TextEditingController();
final TextEditingController _quantityController = new TextEditingController();
/*
"currency_id": "1",
"unit_id": "1",
"case_id": "1",
"price": "4",
"name": "bysicle",
"description": "it is new ",
"quantity": "5",
"country_id": "1",
"category_id": "1"
*/
String _mySelection;
List country_data = List();
String countryid;
Future<String> country() async {
final prefs = await SharedPreferences.getInstance();
final key = 'session_id';
final value = prefs.get(key ) ?? 0;
var res = await http.get(
Uri.encodeFull("http://husam.from-ar.com/api/api-ad/en/1"),
headers: {"Accept": "application/json",
"Authorization" : "$value",
}); //if you have any auth key place here...properly..
var resBody = await json.decode(res.body);
setState(() {
country_data = resBody;
});
return "Sucess";
}
@override
void initState() {
super.initState();
this.country();
}
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Add Product',
home: Scaffold(
body: SingleChildScrollView(
child: Container(
height: MediaQuery.of(context).size.height,
child: new Stack(children: <Widget>[
Positioned(
child: Container(
padding: EdgeInsets.only(top: 40),
child: Column(children: <Widget>[
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children:
<Widget>[
IconButton(
onPressed: () {
Navigator.pop(context);
},
icon: Icon(Icons.arrow_back_ios),
iconSize: 30,
color: Colors.red[300],
),
],),
SizedBox(height: 30,),
SizedBox(
width: 400,
child: Card(
child: Container(
padding: EdgeInsets.only(left: 20, right: 20),
child: Column(children: <Widget>[
SizedBox(height: 9,),
TextField(
controller: _nameController,
obscureText: false,
autofocus: true,
cursorColor: Colors.black,
decoration: InputDecoration(
labelStyle: TextStyle(
color: Colors.black54
),
border: InputBorder.none,
focusedBorder: OutlineInputBorder(
borderSide: BorderSide(color: Colors.red)
),
icon: Icon(Icons.title,
color: Colors.black45,
),
labelText: 'Name',
),
),
SizedBox(height: 9,),
TextField(
obscureText: false,
cursorColor: Colors.black,
controller: _descriptionController,
decoration: InputDecoration(
border: InputBorder.none,
labelStyle: TextStyle(
color: Colors.black54
),
focusedBorder: OutlineInputBorder(
borderSide: BorderSide(color: Colors.red)
),
icon: Icon(Icons.description,
color: Colors.black45,
),
labelText: 'description',
),
),
SizedBox(height: 9,),
TextField(
obscureText: false,
cursorColor: Colors.black,
controller: _quantityController,
decoration: InputDecoration(
border: InputBorder.none,
labelStyle: TextStyle(
color: Colors.black54
),
focusedBorder: OutlineInputBorder(
borderSide: BorderSide(color: Colors.red)
),
icon: Icon(Icons.keyboard_hide,
color: Colors.black45,
),
labelText: 'quantity',
),
),
SizedBox(height: 9,),
TextField(
controller: _priceController,
cursorColor: Colors.black,
decoration: InputDecoration(
border: InputBorder.none,
labelStyle: TextStyle(
color: Colors.black54
),
focusedBorder: OutlineInputBorder(
borderSide: BorderSide(color: Colors.red)
),
icon: Icon(Icons.equalizer,
color: Colors.black45,
),
labelText: 'price',
),
),
],
),),
),
),
Column(
children: <Widget>[
DecoratedBox(
decoration: BoxDecoration(
border: new Border.all(color: Colors.black),
borderRadius: BorderRadius.circular(5.0)),
child: Padding(
padding: EdgeInsets.fromLTRB(10, 5, 0, 0),
//Why you have used Stack ??????
//B'coz it make clickable to whole decorated Box!!!! as you can click anywhere for dropdown !!!
child: Stack(
children: <Widget>[
//Country Text
Text(
"Country: ",
style: TextStyle(
fontSize: 13.0,
),
),
//Dropdown that has no loine beneath
DropdownButtonHideUnderline(
child:
//starting the dropdown
DropdownButton(
items: country_data.map((item) {
return new DropdownMenuItem(
child: new Text(
item['countries']['name'], //Names that the api dropdown contains
style: TextStyle(
fontSize: 13.0,
),
),
value: item['countries']['id'].toString()
//e.g India (Name) and its ID (55fgf5f6frf56f) somethimg like that....
);
}).toList(),
onChanged: (String newVal) {
setState(() {
countryid = newVal;
print(countryid.toString());
});
},
value: countryid,
),
)
],
),
)),
],
),
Center(child: Text('Error: $_error')),
RaisedButton(
child: Text("Pick images"),
onPressed: loadAssets,
),
Expanded(
child: buildGridView(),
),
Container(
height: 50,
child: new RaisedButton(
onPressed: () {
databaseHelper.addData(_descriptionController.text.trim(),
_quantityController.text.trim(),
_nameController.text.trim(),
_priceController.text.trim());
Navigator.of(context).push(
new MaterialPageRoute(
builder: (BuildContext context) => new Dashboard(),
)
);
},
color: Colors.red,
child: new Text(
'Add ad',
style: new TextStyle(
color: Colors.white,
backgroundColor: Colors.red),),
),
),
],
),
),
)
],),
),
),
),
);
}
Widget buildGridView() {
if (images != null)
return GridView.count(
crossAxisCount: 3,
children: List.generate(images.length, (index) {
Asset asset = images[index];
return AssetThumb(
asset: asset,
width: 300,
height: 300,
);
}),
);
else
return Container(color: Colors.white);
}
Future<void> loadAssets() async {
setState(() {
images = List<Asset>();
});
List<Asset> resultList;
String error;
try {
resultList = await MultiImagePicker.pickImages(
maxImages: 6,
);
} on Exception catch (e) {
error = e.toString();
}
// If the widget was removed from the tree while the asynchronous platform
// message was in flight, we want to discard the reply rather than calling
// setState to update our non-existent appearance.
if (!mounted) return;
setState(() {
images = resultList;
if (error == null) _error = 'No Error Dectected';
});
}
}
我的 json 数据
{
"products": [],
"productStatus": [
{
"name": "OLD",
"id": 1
}
],
"countries": [
{
"name": "Turkey",
"id": 1
},
{
"name": "Syria",
"id": 2
}
],
"currencies": [
{
"name": "DOLLAR",
"id": 1
}
],
"units": [
{
"name": "KG",
"id": 1
},
{
"name": "liter",
"id": 2
}
],
"addresses": []
}
我隐藏了我的休息 api
引用我想在 DropDownButton 中显示数据，但它不起作用我的代码没有错误。我的 json 数据它的多个对象我打电话给他，我在调试器中播种了我的数据，但数据没有进入 DropDownButton 为什么我不知道，因为我没有看到任何错误。
解决方案
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