【发布时间】：2019-03-13 14:07:30
【问题描述】：
我将使用真正的 json。首先，我应该运行用Flask编写的项目，然后使用本地主机来实现数据。 这是我正在使用的真正的 Json
{
"devices":[
{
"device_desc":"cooler",
"device_title":"cooler",
"functions":[
{
"device_id":1,
"function_desc":"pomp",
"function_title":"pomp",
"status":1
},
{
"device_id":1,
"function_desc":"less",
"function_title":"less",
"status":1
},
{
"device_id":1,
"function_desc":"up",
"function_title":"up",
"status":1
}
],
"image_path":"fdfdfsf",
"status_id":1,
"statuss":{
"status_desc":"device is on",
"status_title":"on"
}
},
{
"device_desc":"panke",
"device_title":"panke",
"functions":[
{
"device_id":2,
"function_desc":"less",
"function_title":"pomp",
"status":2
},
{
"device_id":2,
"function_desc":"less",
"function_title":"less",
"status":2
}
],
"image_path":"vfx",
"status_id":2,
"statuss":{
"status_desc":"device is off",
"status_title":"off"
}
}
]
}
这是我的代码：
这些是用于定义 json 属性的数据模型：
class Base{
//the type of our object is the array
List<Device> _devices;
Base(this._devices);
List<Device> get devices => _devices;
set devices(List<Device> value) {
_devices = value;
}
}
class Device {
String _device_desc,_device_title,_image_path;
int _status_id;
List<function> _functions;
List<Status> _statuss ;
Device(this._device_desc, this._device_title, this._image_path,
this._status_id, this._functions, this._statuss);
List<Status> get statuss => _statuss;
set statuss(List<Status> value) {
_statuss = value;
}
List<function> get functions => _functions;
set functions(List<function> value) {
_functions = value;
}
int get status_id => _status_id;
set status_id(int value) {
_status_id = value;
}
get image_path => _image_path;
set image_path(value) {
_image_path = value;
}
get device_title => _device_title;
set device_title(value) {
_device_title = value;
}
String get device_desc => _device_desc;
set device_desc(String value) {
_device_desc = value;
}
}
class Status {
String _status_desc, _status_title;
Status(this._status_desc, this._status_title);
get status_title => _status_title;
set status_title(value) {
_status_title = value;
}
String get status_desc => _status_desc;
set status_desc(String value) {
_status_desc = value;
}}
class function {
String _function_desc, _function_title;
int _device_id, _status;
function(this._function_desc, this._function_title, this._device_id,
this._status);
get status => _status;
set status(value) {
_status = value;
}
int get device_id => _device_id;
set device_id(int value) {
_device_id = value;
}
get function_title => _function_title;
set function_title(value) {
_function_title = value;
}
String get function_desc => _function_desc;
set function_desc(String value) {
_function_desc = value;
}}
这是有状态的类：
class MyHomePage extends StatefulWidget {
var title;
MyHomePage({Key key, this.title}) : super(key: key);
@override
_MyHomePageState createState() => new _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
Future<Base> _getBase() async {
var data = await http.get(Uri.encodeFull("http://192.168.1.111:5000/mobile-home"));
var jsonData = json.decode(data.body);
Base base = Base(jsonData);
return Base(jsonData[0]);
}
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text(widget.title),
),
body: Container(
child: FutureBuilder(
future: _getBase(),
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.data == null) {
return Container(
child: Center(
child: Text("Loading..."),
),
);
} else {
return ListView.builder(
itemCount: snapshot.data.devices.length,
itemBuilder: (BuildContext context, int index) {
snapshot.data.devices.map<Widget>((devices){
return ListTile(
subtitle: Text(devices[index].device_desc.toString()),
title: Text(devices[index].device_title),
/*leading: CircleAvatar(
// ignore: argument_type_not_assignable
backgroundImage: NetworkImage(snapshot.data[index].thumbnailUrl),
)*/
);
}
);
},
);
}
},
),
),
);
}
}
调试时出错：
"type 'List<dynamic>' is not a subtype of type 'List<Device>'"
我无法从 json 中获取数据。
【问题讨论】：