因此，根据您提供的数据，我创建了以下代码：
import 'package:date_time_picker/date_time_picker.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_app/Patner.dart';
import 'package:flutter_app/dataModel.dart';
import 'package:http/http.dart' as http;
void main() {
runApp(MaterialApp(
debugShowCheckedModeBanner: false,
home: MyApp(),
));
}
class MyApp extends StatefulWidget {
const MyApp({Key key}) : super(key: key);
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
Partner _selectedLab;
Datum _selectedTest;
Future getAllPathLabResults;
Future getTestByLabResult;
String encLabId = '';
void initState() {
super.initState();
getAllPathLabResults = allPathLab();
getTestByLabResult = getTestByLab();
}
String _selectedDate = DateTime.now().toString();
Future<List<Partner>> allPathLab() async {
String jsonData = jsonstring;
final model = modelFromJson(jsonData);
print("This is the list length : ${model.partner.length}");
List<Partner> arrData = model.partner;
// this Future is for sample as you will be fetching the api data remove this one
Future.delayed(Duration(seconds: 3));
return arrData;
}
Future<List<Datum>> getTestByLab() async {
print("This is the Id :$encLabId");
_selectedTest = null;
var response = await http.post(
Uri.parse("http://medbo.digitalicon.in/api/medboapi/GetTestByLab"),
body: ({"EncId": encLabId}));
if (response.statusCode == 200) {
final dataModel = dataModelFromJson(response.body);
print(dataModel.data.length);
for (final item in dataModel.data) {
print("This is hte test name :${item.testName}");
}
List<Datum> arrData = dataModel.data;
return arrData;
}
return [];
}
@override
Widget build(BuildContext context) {
var screenWidth = MediaQuery.of(context).size.width;
var screenHeight = MediaQuery.of(context).size.height;
var blockSizeHorizontal = (screenWidth / 100);
var blockSizeVertical = (screenHeight / 100);
return Scaffold(
body: SafeArea(
child: Container(
child: Column(
children: [
Padding(
padding: const EdgeInsets.all(8.0),
child: ListTile(
title: Text("Booking Information",
style: TextStyle(
fontWeight: FontWeight.bold,
fontSize: blockSizeHorizontal * 5,
fontFamily: 'Poppins',
color: Theme.of(context).primaryColor,
)),
subtitle: Text("Preferred Visit Date"),
),
),
Container(
margin: EdgeInsets.only(left: 20),
padding: EdgeInsets.only(left: 0, right: 150),
decoration: BoxDecoration(
color: Colors.lightBlue[50],
borderRadius: BorderRadius.all(Radius.circular(12)),
),
child: Padding(
padding: const EdgeInsets.all(8.0),
child: DateTimePicker(
initialValue: DateTime.now().toString(),
//initialValue:'', // initialValue or controller.text can be null, empty or a DateTime string otherwise it will throw an error.
type: DateTimePickerType.date,
dateLabelText: 'Select Date',
style: TextStyle(
fontWeight: FontWeight.bold,
fontSize: blockSizeHorizontal * 3.5,
fontFamily: 'Poppins',
color: Colors.green,
letterSpacing: 2.0,
),
firstDate: DateTime.now(),
lastDate: DateTime.now().add(Duration(days: 30)),
// This will add one year from current date
validator: (value) {
return null;
},
onChanged: (value) {
if (value.isNotEmpty) {
setState(() {
_selectedDate = value;
});
}
},
onSaved: (value) {
if (value.isNotEmpty) {
_selectedDate = value;
}
},
),
),
),
ListTile(
title: Text(
"Select Pathological Lab",
style: TextStyle(
fontWeight: FontWeight.bold,
fontSize: blockSizeHorizontal * 4.0,
fontFamily: 'Poppins',
color: Theme.of(context).primaryColor,
),
),
),
Container(
child: FutureBuilder<List<Partner>>(
future: getAllPathLabResults,
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.connectionState != ConnectionState.done) {
return CircularProgressIndicator();
}
if (snapshot.hasError) {
return Text("Somthing went wrong");
}
if (snapshot.hasData) {
List<Partner> data =
snapshot.hasData ? snapshot.data : [];
return DropdownButton<Partner>(
value: _selectedLab,
hint: Text("Select Lab"),
//underline: SizedBox(),
//isExpanded: true,
items: data
.map((Partner data) => DropdownMenuItem<Partner>(
child: Text("${data.partnerName}"),
value: data,
))
.toList()
.cast<DropdownMenuItem<Partner>>(),
onChanged: (value) {
setState(() {
_selectedLab = value;
encLabId = value.encPartnerId;
getTestByLabResult = getTestByLab();
});
//GetTestByLab(value!.encPartnerId); // passing encid to my next API function
// GetTestByLab();
},
);
}
return Text("Waiting for Internet Connection");
},
),
),
//=========================================================== Dependent drop down===================================
ListTile(
title: Text(
"Test Name",
style: TextStyle(
fontWeight: FontWeight.bold,
fontSize: blockSizeHorizontal * 4.0,
fontFamily: 'Poppins',
color: Theme.of(context).primaryColor,
),
),
),
Container(
child: FutureBuilder<List<Datum>>(
future: getTestByLabResult,
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.connectionState != ConnectionState.done) {
return CircularProgressIndicator();
}
if (snapshot.hasError) {
return Text("Select a Lab for your Test");
}
if (snapshot.hasData) {
List<Datum> data = snapshot.hasData ? snapshot.data : [];
return DropdownButton<Datum>(
value: _selectedTest,
hint: Text(""),
//underline: SizedBox(),
//isExpanded: true,
items: data
.map((Datum data) => DropdownMenuItem<Datum>(
child: Text("${data.testName}"),
value: data,
))
.toList()
.cast<DropdownMenuItem<Datum>>(),
onChanged: (value) {
print("This is the value : ${value.testName}");
setState(() {
_selectedTest = value;
});
//GetTestByLab(value!.encPartnerId); // passing encid to my next API function
});
}
return Text("Waiting for Internet Connection");
},
),
),
],
),
),
),
);
}
}
// used this as a sample
String jsonstring = '''{
"Status": "1",
"Message": "",
"Partner": [
{
"EncPartnerId": "IujyQXg8KZg8asLvK/FS7g==",
"PartnerName": "dasfdsf"
},
{
"EncPartnerId": "pEl2B9kuumKRxIxLJO76eQ==",
"PartnerName": "partner172"
},
{
"EncPartnerId": "eYwtNBXR6P/JDtsIwr+Bvw==",
"PartnerName": "nnkb"
},
{
"EncPartnerId": "kFgorcFF0G6RQD4W+LwWnQ==",
"PartnerName": "nnkjj"
},
{
"EncPartnerId": "U4exk+vfMGrn7cjNUa/PBw==",
"PartnerName": "mahadev"
},
{
"EncPartnerId": "tqkaSjTFgDf0612mp9mbsQ==",
"PartnerName": null
},
{
"EncPartnerId": "0aruO0FbYOu5IerRBxdT8w==",
"PartnerName": "Suraksha Diagnostics"
},
{
"EncPartnerId": "65gtodyhbtdInTsJWr1ZkA==",
"PartnerName": "Rasomoy pvt. Hospital"
},
{
"EncPartnerId": "LEuT1eIlpLEMAAkZme3wpQ==",
"PartnerName": "Tangra medical House"
},
{
"EncPartnerId": "q8O8YMzYKXSB4RtkX4k7Lw==",
"PartnerName": "Partner new"
}
]
}''';
API 模型：
// To parse this JSON data, do
//
// final model = modelFromJson(jsonString);
import 'dart:convert';
Model modelFromJson(String str) => Model.fromJson(json.decode(str));
String modelToJson(Model data) => json.encode(data.toJson());
class Model {
Model({
this.status,
this.message,
this.partner,
});
String status;
String message;
List<Partner> partner;
factory Model.fromJson(Map<String, dynamic> json) => Model(
status: json["Status"],
message: json["Message"],
partner:
List<Partner>.from(json["Partner"].map((x) => Partner.fromJson(x))),
);
Map<String, dynamic> toJson() => {
"Status": status,
"Message": message,
"Partner": List<dynamic>.from(partner.map((x) => x.toJson())),
};
}
class Partner {
Partner({
this.encPartnerId,
this.partnerName,
});
String encPartnerId;
String partnerName;
factory Partner.fromJson(Map<String, dynamic> json) => Partner(
encPartnerId: json["EncPartnerId"],
partnerName: json["PartnerName"] == null ? null : json["PartnerName"],
);
Map<String, dynamic> toJson() => {
"EncPartnerId": encPartnerId,
"PartnerName": partnerName == null ? null : partnerName,
};
}
第二个api解析模型
// To parse this JSON data, do
//
// final dataModel = dataModelFromJson(jsonString);
import 'dart:convert';
DataModel dataModelFromJson(String str) => DataModel.fromJson(json.decode(str));
String dataModelToJson(DataModel data) => json.encode(data.toJson());
class DataModel {
DataModel({
this.status,
this.message,
this.data,
});
String status;
String message;
List<Datum> data;
factory DataModel.fromJson(Map<String, dynamic> json) => DataModel(
status: json["Status"],
message: json["Message"],
data: json["Data"] == null
? []
: List<Datum>.from(json["Data"].map((x) => Datum.fromJson(x))),
);
Map<String, dynamic> toJson() => {
"Status": status,
"Message": message,
"Data":
data == null ? [] : List<dynamic>.from(data.map((x) => x.toJson())),
};
}
class Datum {
Datum({
this.testId,
this.encTestId,
this.testName,
this.noOfPartner,
this.testFee,
this.discountedFee,
this.bookingFee,
this.reportTime,
this.note,
this.createBy,
this.createDate,
this.modBy,
this.modDate,
this.activeStatus,
this.permission,
});
String testId;
dynamic encTestId;
String testName;
dynamic noOfPartner;
dynamic testFee;
dynamic discountedFee;
dynamic bookingFee;
dynamic reportTime;
dynamic note;
dynamic createBy;
dynamic createDate;
dynamic modBy;
dynamic modDate;
dynamic activeStatus;
dynamic permission;
factory Datum.fromJson(Map<String, dynamic> json) => Datum(
testId: json["TestId"],
encTestId: json["EncTestId"],
testName: json["TestName"],
noOfPartner: json["NoOfPartner"],
testFee: json["TestFee"],
discountedFee: json["DiscountedFee"],
bookingFee: json["BookingFee"],
reportTime: json["ReportTime"],
note: json["Note"],
createBy: json["CreateBy"],
createDate: json["CreateDate"],
modBy: json["ModBy"],
modDate: json["ModDate"],
activeStatus: json["ActiveStatus"],
permission: json["Permission"],
);
Map<String, dynamic> toJson() => {
"TestId": testId,
"EncTestId": encTestId,
"TestName": testName,
"NoOfPartner": noOfPartner,
"TestFee": testFee,
"DiscountedFee": discountedFee,
"BookingFee": bookingFee,
"ReportTime": reportTime,
"Note": note,
"CreateBy": createBy,
"CreateDate": createDate,
"ModBy": modBy,
"ModDate": modDate,
"ActiveStatus": activeStatus,
"Permission": permission,
};
}
因此，当您最初根据 id 获取数据并选择第二个下拉菜单时。现在，当您更改实验室时，您可以将所选文本设为空。
而且您还以错误的方式使用了futurebuilder方法，因为调用了setstate它正在创建多个rebuids并给出错误。
请运行代码并检查其是否正常工作。