设备上的 Flutter 保存按钮状态
Flutter Saving button state on device
我有一个搜索屏幕，用户可以在其中搜索一个县，并显示该县的 post 疫苗接种列表。有的县多有的少。
在疫苗接种列表 posts 中，有一个按钮，按下后该按钮将被禁用。到这里为止一切都很好，但是当我重新搜索同一个县时，曾经被禁用的按钮不再被禁用，这意味着它可以再次按下。我想避免这种情况。
我有一个布尔值列表，每次疫苗接种都为“真”post。按下按钮时，列表中的相应索引将更改为“false”，从而禁用该按钮。
问题：如何让按钮保持禁用状态？ （是否重新搜索同一个县或重新打开应用程序）
import 'package:colour/colour.dart';
import 'package:firebase_database/firebase_database.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:google_fonts/google_fonts.dart';
import 'dart:async';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
// import 'package:shared_preferences/shared_preferences.dart';
class VaccineCenterList extends StatefulWidget {
const VaccineCenterList({key}) : super(key: key);
static const String idScreen = "VaccineCenterList";
@override
_VaccineCenterListState createState() => _VaccineCenterListState();
}
class _VaccineCenterListState extends State<VaccineCenterList> {
TextEditingController hospitalCountyEditingController =
TextEditingController();
final databaseReference = FirebaseDatabase.instance.reference();
final firestoreInstance = FirebaseFirestore.instance;
FirebaseAuth auth = FirebaseAuth.instance;
List<Hospitals> driverList = [];
List<bool> buttonPressed = [];
// Map<String, List> buttonPressed = {};
buttonControls(numOfLocations) {
print(numOfLocations);
int checker = 0;
if (numOfLocations > buttonPressed.length) {
try {
while (numOfLocations >= checker) {
buttonPressed.add(true);
checker = checker + 1;
}
} catch (e) {
print("$e");
}
} else {}
print(buttonPressed);
}
@override
void initState() {
super.initState();
print("I'm in the vaccine list search screen");
}
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.grey[100],
appBar: AppBar(
backgroundColor: Colors.grey[100],
centerTitle: true,
elevation: 0,
iconTheme: const IconThemeData(
color: Colors.black,
),
title: Text(
"Pamoja",
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
color: Colors.black,
fontSize: 35,
),
),
),
body: GestureDetector(
onTap: () {
FocusScope.of(context).requestFocus(FocusNode());
},
child: SingleChildScrollView(
child: Column(
children: [
Container(
// textfield
padding: const EdgeInsets.all(8.0),
child: TextField(
controller: hospitalCountyEditingController,
keyboardType: TextInputType.text,
textCapitalization: TextCapitalization.words,
decoration: InputDecoration(
border: const OutlineInputBorder(
borderSide: BorderSide(
color: Colors.black,
style: BorderStyle.solid,
width: 1,
),
),
labelText: "Search County",
labelStyle: const TextStyle(
fontSize: 14.0,
color: Colors.blueGrey,
),
hintStyle: GoogleFonts.lexendMega(
color: Colors.grey,
fontSize: 10,
),
),
style: GoogleFonts.lexendMega(
fontSize: 14,
color: Colors.black,
),
),
),
ElevatedButton(
// search button
onPressed: () {
setState(() {
FocusScope.of(context).requestFocus(
FocusNode(),
);
driverList.clear();
if (hospitalCountyEditingController.text == "" ||
hospitalCountyEditingController.text == " ") {
isTrueOrFalse = "False";
} else {
isTrueOrFalse = "True";
}
});
getHospitalDetails();
},
child: Text(
"Search",
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
),
),
),
SingleChildScrollView(
child: Column(
children: [
SizedBox(
height: MediaQuery.of(context).size.height,
// height: 50,
// color: Colors.black,
child: Padding(
padding: const EdgeInsets.only(
right: 12.0,
left: 12.0,
bottom: 12.0,
),
child: driverList.isEmpty
? Center(
// child: CircularProgressIndicator(),
child: (isTrueOrFalse == "True")
? const CircularProgressIndicator()
: Column(
mainAxisAlignment:
MainAxisAlignment.center,
children: [
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
"Search for one of the counties below",
style:
GoogleFonts.lexendMega()),
),
Text(
"Nairobi, Baringo, Busia, Bomet, Bungoma, Elgeyo Marakwet, Embu, Garissa, Homa Bay, Isiolo, Kajiado, Kakamega, Kericho, Kiambu, Kilifi, Kirinyaga, Kisii, Kisumu, Kitui, Kwale, Laikipia, Lamu, Machakos, Makueni, Mandera, Marsabit, Meru, Migori, Mombasa, Muranga, Nakuru, Nandi, Narok, Nyamira, Nyandarua, Nyeri, Samburu, Siaya County, Taita Taveta, Tana River County, Tharaka Nithi, Trans Nzoia, Turkana, Uasin Gishu, Vihiga, Wajir, West Pokot",
textAlign: TextAlign.center,
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
),
),
],
),
)
: ListView.builder(
itemCount: driverList.length,
itemBuilder: (context, index) {
final Hospitals hospitals = driverList[index];
final String hospitalLocaiton =
hospitals.location;
final String hospitalPhone = hospitals.phone;
final String hospitalName = hospitals.name;
positiveCount = hospitals.positiveCount;
negativeCount = hospitals.negativeCount;
final int setpercentage =
calculatePositivePercentage(
positiveCount, negativeCount);
buttonControls(driverList.length);
return Padding(
padding: const EdgeInsets.all(8.0),
child: Card(
elevation: 0,
child: ExpansionTile(
title: Text(
hospitalName.toUpperCase(),
style: GoogleFonts.lexendMega(),
textAlign: TextAlign.center,
),
children: [
Column(
children: [
Container(
child: (hospitalPhone
.isNotEmpty)
? ElevatedButton(
onPressed: () {
Clipboard.setData(
ClipboardData(
text:
hospitalPhone,
),
);
ScaffoldMessenger.of(
context)
.showSnackBar(
const SnackBar(
backgroundColor:
Colors.green,
content: Text(
"Number Copied",
textAlign:
TextAlign
.center,
),
),
);
},
child: Text(
hospitalPhone,
textAlign:
TextAlign.center,
style: GoogleFonts
.lexendMega(
fontSize: 13),
),
style: ElevatedButton
.styleFrom(
elevation: 0,
),
)
: const Text(""),
),
const SizedBox(
height: 5,
),
hospitalLocaiton.isNotEmpty
? Container(
padding:
const EdgeInsets.all(
8),
decoration: BoxDecoration(
border: Border.all(
color: Colors.black,
),
borderRadius:
BorderRadius
.circular(10),
),
child: Text(
hospitalLocaiton,
textAlign:
TextAlign.center,
style: GoogleFonts
.lexendMega(
fontSize: 12,
),
),
)
: Text(
hospitalLocaiton,
textAlign:
TextAlign.center,
style: GoogleFonts
.lexendMega(
fontSize: 12,
),
),
const SizedBox(
height: 10,
),
Text(
"$setpercentage% (percent) of voters say this hospital administer vaccines.",
textAlign: TextAlign.center,
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
fontSize: 12,
color: Colors.deepPurple[400],
),
),
const SizedBox(
height: 10,
),
const Divider(
// thickness: 1,
indent: 20,
endIndent: 20,
color: Colors.black87,
),
const SizedBox(
height: 10,
),
Text(
"Does this Hospital administer Vaccines?\n(To help the public, please vote only if you know.)",
textAlign: TextAlign.center,
style: GoogleFonts.lexendMega(
fontSize: 12,
fontWeight: FontWeight.bold,
),
),
Column(
children: [
Row(
mainAxisAlignment:
MainAxisAlignment
.spaceEvenly,
children: [
ElevatedButton(
onPressed:
buttonPressed[index]
? () {
positiveIncrement(
hospitalName,
index);
buttonPressed[
index] =
false;
ScaffoldMessenger.of(
context)
.showSnackBar(
const SnackBar(
backgroundColor:
Colors.redAccent,
content:
Text(
"Voted",
textAlign:
TextAlign.center,
),
),
);
}
: null,
child: Text(
"Yes",
style: GoogleFonts
.lexendMega(),
),
style: ElevatedButton
.styleFrom(
primary:
Colour("#87D68D"),
),
),
ElevatedButton(
onPressed:
buttonPressed[index]
? () {
negativeIncrement(
hospitalName,
index);
buttonPressed[
index] =
false;
ScaffoldMessenger.of(
context)
.showSnackBar(
const SnackBar(
backgroundColor:
Colors.redAccent,
content:
Text(
"Voted",
textAlign:
TextAlign.center,
),
),
);
}
: null,
child: Text(
"No",
style: GoogleFonts
.lexendMega(),
),
style: ElevatedButton
.styleFrom(
primary:
Colour("#E3655B"),
),
),
],
),
const SizedBox(
height: 10,
),
Text(
"1 - To vote, tap once\n2 - To Undo vote, tap and hold",
style:
GoogleFonts.lexendMega(
fontSize: 12,
),
textAlign: TextAlign.start,
),
const SizedBox(
height: 10,
),
],
),
],
),
],
),
),
);
},
),
),
),
// SizedBox(height: 40),
],
),
),
],
),
),
),
);
}
}
class Hospitals {
final String name;
final String phone;
final String location;
// final String county;
final int positiveCount;
final int negativeCount;
// final int intPercentage;
// final int totalVotes;
Hospitals({
required this.name,
required this.phone,
required this.location,
// required this.county,
required this.positiveCount,
required this.negativeCount,
// required this.intPercentage,
// required this.totalVotes,
});
static Hospitals fromJson(Map<String, dynamic> json) {
return Hospitals(
name: json['HospitalName'],
phone: json['HospitalPhone'],
// county: json['county'],
location: json['HospitalAddres'],
positiveCount: json['poitiveCount'],
negativeCount: json['negativeCount'],
// intPercentage: json['intPercentage'],
// totalVotes: json['totalVotes']
);
}
}
我是这样做的：使用provider设置值，使boolean值
late bool isMyButtonEnabled;
//in initState
setState(() {
isMyButtonEnabled=
myProvider.checkIfButtonShouldBeEnabled(widget.Id);
}
//in build
ElevatedButton(
child: Text('SUBMIT'),
onPressed: !isMyButtonEnabled
? null
: () async => {
//some code
}
通过这种方式，您的 boolean 将使用 Provider 包保存并在应用程序中随处可用（那里也可以使用其他更高级的 Provider 类似物）
我有一个搜索屏幕，用户可以在其中搜索一个县，并显示该县的 post 疫苗接种列表。有的县多有的少。
在疫苗接种列表 posts 中，有一个按钮，按下后该按钮将被禁用。到这里为止一切都很好，但是当我重新搜索同一个县时，曾经被禁用的按钮不再被禁用，这意味着它可以再次按下。我想避免这种情况。
我有一个布尔值列表，每次疫苗接种都为“真”post。按下按钮时，列表中的相应索引将更改为“false”，从而禁用该按钮。
问题：如何让按钮保持禁用状态？ （是否重新搜索同一个县或重新打开应用程序）
import 'package:colour/colour.dart';
import 'package:firebase_database/firebase_database.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:google_fonts/google_fonts.dart';
import 'dart:async';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
// import 'package:shared_preferences/shared_preferences.dart';
class VaccineCenterList extends StatefulWidget {
const VaccineCenterList({key}) : super(key: key);
static const String idScreen = "VaccineCenterList";
@override
_VaccineCenterListState createState() => _VaccineCenterListState();
}
class _VaccineCenterListState extends State<VaccineCenterList> {
TextEditingController hospitalCountyEditingController =
TextEditingController();
final databaseReference = FirebaseDatabase.instance.reference();
final firestoreInstance = FirebaseFirestore.instance;
FirebaseAuth auth = FirebaseAuth.instance;
List<Hospitals> driverList = [];
List<bool> buttonPressed = [];
// Map<String, List> buttonPressed = {};
buttonControls(numOfLocations) {
print(numOfLocations);
int checker = 0;
if (numOfLocations > buttonPressed.length) {
try {
while (numOfLocations >= checker) {
buttonPressed.add(true);
checker = checker + 1;
}
} catch (e) {
print("$e");
}
} else {}
print(buttonPressed);
}
@override
void initState() {
super.initState();
print("I'm in the vaccine list search screen");
}
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.grey[100],
appBar: AppBar(
backgroundColor: Colors.grey[100],
centerTitle: true,
elevation: 0,
iconTheme: const IconThemeData(
color: Colors.black,
),
title: Text(
"Pamoja",
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
color: Colors.black,
fontSize: 35,
),
),
),
body: GestureDetector(
onTap: () {
FocusScope.of(context).requestFocus(FocusNode());
},
child: SingleChildScrollView(
child: Column(
children: [
Container(
// textfield
padding: const EdgeInsets.all(8.0),
child: TextField(
controller: hospitalCountyEditingController,
keyboardType: TextInputType.text,
textCapitalization: TextCapitalization.words,
decoration: InputDecoration(
border: const OutlineInputBorder(
borderSide: BorderSide(
color: Colors.black,
style: BorderStyle.solid,
width: 1,
),
),
labelText: "Search County",
labelStyle: const TextStyle(
fontSize: 14.0,
color: Colors.blueGrey,
),
hintStyle: GoogleFonts.lexendMega(
color: Colors.grey,
fontSize: 10,
),
),
style: GoogleFonts.lexendMega(
fontSize: 14,
color: Colors.black,
),
),
),
ElevatedButton(
// search button
onPressed: () {
setState(() {
FocusScope.of(context).requestFocus(
FocusNode(),
);
driverList.clear();
if (hospitalCountyEditingController.text == "" ||
hospitalCountyEditingController.text == " ") {
isTrueOrFalse = "False";
} else {
isTrueOrFalse = "True";
}
});
getHospitalDetails();
},
child: Text(
"Search",
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
),
),
),
SingleChildScrollView(
child: Column(
children: [
SizedBox(
height: MediaQuery.of(context).size.height,
// height: 50,
// color: Colors.black,
child: Padding(
padding: const EdgeInsets.only(
right: 12.0,
left: 12.0,
bottom: 12.0,
),
child: driverList.isEmpty
? Center(
// child: CircularProgressIndicator(),
child: (isTrueOrFalse == "True")
? const CircularProgressIndicator()
: Column(
mainAxisAlignment:
MainAxisAlignment.center,
children: [
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
"Search for one of the counties below",
style:
GoogleFonts.lexendMega()),
),
Text(
"Nairobi, Baringo, Busia, Bomet, Bungoma, Elgeyo Marakwet, Embu, Garissa, Homa Bay, Isiolo, Kajiado, Kakamega, Kericho, Kiambu, Kilifi, Kirinyaga, Kisii, Kisumu, Kitui, Kwale, Laikipia, Lamu, Machakos, Makueni, Mandera, Marsabit, Meru, Migori, Mombasa, Muranga, Nakuru, Nandi, Narok, Nyamira, Nyandarua, Nyeri, Samburu, Siaya County, Taita Taveta, Tana River County, Tharaka Nithi, Trans Nzoia, Turkana, Uasin Gishu, Vihiga, Wajir, West Pokot",
textAlign: TextAlign.center,
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
),
),
],
),
)
: ListView.builder(
itemCount: driverList.length,
itemBuilder: (context, index) {
final Hospitals hospitals = driverList[index];
final String hospitalLocaiton =
hospitals.location;
final String hospitalPhone = hospitals.phone;
final String hospitalName = hospitals.name;
positiveCount = hospitals.positiveCount;
negativeCount = hospitals.negativeCount;
final int setpercentage =
calculatePositivePercentage(
positiveCount, negativeCount);
buttonControls(driverList.length);
return Padding(
padding: const EdgeInsets.all(8.0),
child: Card(
elevation: 0,
child: ExpansionTile(
title: Text(
hospitalName.toUpperCase(),
style: GoogleFonts.lexendMega(),
textAlign: TextAlign.center,
),
children: [
Column(
children: [
Container(
child: (hospitalPhone
.isNotEmpty)
? ElevatedButton(
onPressed: () {
Clipboard.setData(
ClipboardData(
text:
hospitalPhone,
),
);
ScaffoldMessenger.of(
context)
.showSnackBar(
const SnackBar(
backgroundColor:
Colors.green,
content: Text(
"Number Copied",
textAlign:
TextAlign
.center,
),
),
);
},
child: Text(
hospitalPhone,
textAlign:
TextAlign.center,
style: GoogleFonts
.lexendMega(
fontSize: 13),
),
style: ElevatedButton
.styleFrom(
elevation: 0,
),
)
: const Text(""),
),
const SizedBox(
height: 5,
),
hospitalLocaiton.isNotEmpty
? Container(
padding:
const EdgeInsets.all(
8),
decoration: BoxDecoration(
border: Border.all(
color: Colors.black,
),
borderRadius:
BorderRadius
.circular(10),
),
child: Text(
hospitalLocaiton,
textAlign:
TextAlign.center,
style: GoogleFonts
.lexendMega(
fontSize: 12,
),
),
)
: Text(
hospitalLocaiton,
textAlign:
TextAlign.center,
style: GoogleFonts
.lexendMega(
fontSize: 12,
),
),
const SizedBox(
height: 10,
),
Text(
"$setpercentage% (percent) of voters say this hospital administer vaccines.",
textAlign: TextAlign.center,
style: GoogleFonts.lexendMega(
fontWeight: FontWeight.bold,
fontSize: 12,
color: Colors.deepPurple[400],
),
),
const SizedBox(
height: 10,
),
const Divider(
// thickness: 1,
indent: 20,
endIndent: 20,
color: Colors.black87,
),
const SizedBox(
height: 10,
),
Text(
"Does this Hospital administer Vaccines?\n(To help the public, please vote only if you know.)",
textAlign: TextAlign.center,
style: GoogleFonts.lexendMega(
fontSize: 12,
fontWeight: FontWeight.bold,
),
),
Column(
children: [
Row(
mainAxisAlignment:
MainAxisAlignment
.spaceEvenly,
children: [
ElevatedButton(
onPressed:
buttonPressed[index]
? () {
positiveIncrement(
hospitalName,
index);
buttonPressed[
index] =
false;
ScaffoldMessenger.of(
context)
.showSnackBar(
const SnackBar(
backgroundColor:
Colors.redAccent,
content:
Text(
"Voted",
textAlign:
TextAlign.center,
),
),
);
}
: null,
child: Text(
"Yes",
style: GoogleFonts
.lexendMega(),
),
style: ElevatedButton
.styleFrom(
primary:
Colour("#87D68D"),
),
),
ElevatedButton(
onPressed:
buttonPressed[index]
? () {
negativeIncrement(
hospitalName,
index);
buttonPressed[
index] =
false;
ScaffoldMessenger.of(
context)
.showSnackBar(
const SnackBar(
backgroundColor:
Colors.redAccent,
content:
Text(
"Voted",
textAlign:
TextAlign.center,
),
),
);
}
: null,
child: Text(
"No",
style: GoogleFonts
.lexendMega(),
),
style: ElevatedButton
.styleFrom(
primary:
Colour("#E3655B"),
),
),
],
),
const SizedBox(
height: 10,
),
Text(
"1 - To vote, tap once\n2 - To Undo vote, tap and hold",
style:
GoogleFonts.lexendMega(
fontSize: 12,
),
textAlign: TextAlign.start,
),
const SizedBox(
height: 10,
),
],
),
],
),
],
),
),
);
},
),
),
),
// SizedBox(height: 40),
],
),
),
],
),
),
),
);
}
}
class Hospitals {
final String name;
final String phone;
final String location;
// final String county;
final int positiveCount;
final int negativeCount;
// final int intPercentage;
// final int totalVotes;
Hospitals({
required this.name,
required this.phone,
required this.location,
// required this.county,
required this.positiveCount,
required this.negativeCount,
// required this.intPercentage,
// required this.totalVotes,
});
static Hospitals fromJson(Map<String, dynamic> json) {
return Hospitals(
name: json['HospitalName'],
phone: json['HospitalPhone'],
// county: json['county'],
location: json['HospitalAddres'],
positiveCount: json['poitiveCount'],
negativeCount: json['negativeCount'],
// intPercentage: json['intPercentage'],
// totalVotes: json['totalVotes']
);
}
}
我是这样做的：使用provider设置值，使boolean值
late bool isMyButtonEnabled;
//in initState
setState(() {
isMyButtonEnabled=
myProvider.checkIfButtonShouldBeEnabled(widget.Id);
}
//in build
ElevatedButton(
child: Text('SUBMIT'),
onPressed: !isMyButtonEnabled
? null
: () async => {
//some code
}
通过这种方式，您的 boolean 将使用 Provider 包保存并在应用程序中随处可用（那里也可以使用其他更高级的 Provider 类似物）