我有一个为测试应用程序制作的导航菜单，如果我没有登录到应用程序，我想隐藏一些选项卡。一旦我登录，这些选项卡就会出现。这是我的导航菜单代码。
import 'package:flutter/material.dart';
import 'package:flutter_app_seals/Status.dart';
import 'package:flutter_app_seals/Seals_List.dart';
import 'package:flutter/widgets.dart';
import 'package:flutter_app_seals/auth_page.dart';
import 'package:flutter_app_seals/Setting_glob.dart';
import 'package:sentry_flutter/sentry_flutter.dart';
import 'package:flutter_app_seals/model/add_seals/JsonAddSeals.dart';
import 'package:flutter_app_seals/model/user_page/page.dart';
import 'package:flutter_app_seals/model/setting/globalvar.dart' as global;
class Main_Page extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
home: new LoginPage());
}
}
class LoginPage extends StatefulWidget {
@override
_LoginPageState createState() => _LoginPageState();
}
class _LoginPageState extends State<LoginPage> {
int _pageIndex = 0;
PageController _pageController;
List<Widget> tabPages = [
Login(),
Setting(),
UserPage(),
Status_Obj(),
Status_seals(),
JsonParseAddSeals(),
];
@override
void initState(){
super.initState();
_pageController = PageController(initialPage: _pageIndex);
}
@override
void dispose() {
_pageController.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return WillPopScope(
child: new Scaffold(
resizeToAvoidBottomInset: false,
bottomNavigationBar: BottomNavigationBar(
showSelectedLabels: true, // <-- HERE
showUnselectedLabels: true, // <-- AND
currentIndex: _pageIndex,
onTap: onTabTapped,
backgroundColor: Colors.blue,
items: <BottomNavigationBarItem>[
new BottomNavigationBarItem( icon: Icon(Icons.admin_panel_settings_outlined), title: Text(" Вхід"),backgroundColor: Colors.lightBlue),
new BottomNavigationBarItem(icon: Icon(Icons.settings), title: Text("Налаштування"),backgroundColor: Colors.lightBlue),
if(global.nameUser ?.isNotEmpty == true)...[
new BottomNavigationBarItem(icon: Icon(Icons.person_pin), title: Text("Користувач"),backgroundColor: Colors.lightBlue),
new BottomNavigationBarItem(icon: Icon(Icons.home), title: Text("Пломбування"),backgroundColor: Colors.lightBlue),
new BottomNavigationBarItem(icon: Icon(Icons.qr_code), title: Text("Пломби"),backgroundColor: Colors.lightBlue),
new BottomNavigationBarItem(icon: Icon(Icons.add_outlined), title: Text("Акт приймання"),backgroundColor: Colors.lightBlue),
]
],
),
body: PageView(
children: tabPages,
onPageChanged: onPageChanged,
controller: _pageController,
),
),
);
}
void onPageChanged(int page) {
setState(() {
this._pageIndex = page;
});
}
void onTabTapped(int index) {
this._pageController.animateToPage(index,duration: const Duration(milliseconds: 500),curve: Curves.easeInOut);
}
}问题是，当我登录到所需的页面时，我没有看到导航菜单的所有图标。为了让它们出现，我需要点击其中一个可用的图标(只有2个图标可用于授权(，然后导航菜单才会更新，一切都会正常。所有6个图标都将可见！这是我的自动授权码：
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'Status.dart';
import 'dart:io';
import 'package:flutter_app_seals/model/setting/globalvar.dart' as global;
import 'package:flutter_aes_ecb_pkcs5/flutter_aes_ecb_pkcs5.dart';
import 'package:flutter/widgets.dart';
import 'package:path_provider/path_provider.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter_app_seals/model/user_page/page.dart' ;
void main() => runApp(Login());
class Login extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
home: new LoginPage(
storage: Storage()
)
);
}
}
class LoginPage extends StatefulWidget {
final Storage storage;
LoginPage({Key key, @required this.storage}) : super(key: key);
@override
_LoginPageState createState() => _LoginPageState();
}
class _LoginPageState extends State<LoginPage> {
//Info about users
String state;
@override
void initState() {
super.initState();
widget.storage.readData().then((String value) {
setState(() {
global.urlVar = value;
});
});
}
bool _isLoading = false;
@override
Widget build(BuildContext context) {
SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle.light.copyWith(statusBarColor: Colors.transparent));
return Scaffold(
body: Container(
decoration: BoxDecoration(
gradient: LinearGradient(
colors: [Colors.blue, Colors.white],
begin: Alignment.topCenter,
end: Alignment.bottomCenter),
),
child: _isLoading ? Center(child: CircularProgressIndicator()) : ListView(
children: <Widget>[
headerSection(),
textSection(),
buttonSection(),
],
),
),
);
}
signIn(String login, pass) async {
SharedPreferences sharedPreferences = await SharedPreferences.getInstance();
var AESLogin = login;
var AESpass = pass;
//generate a 16-byte random key
var key = '123111111111111111121212';
print(key);
//encrypt
var encryptLogin = await FlutterAesEcbPkcs5.encryptString(AESLogin, key);
var encryptPass = await FlutterAesEcbPkcs5.encryptString(AESpass, key);
HttpClient client = new HttpClient();
client.badCertificateCallback = ((X509Certificate cert, String host, int port) => true);
String url = 'testUrl';
Map map = {
"login": encryptLogin,
"pass": encryptPass
};
HttpClientRequest request = await client.postUrl(Uri.parse(url));
request.headers.set('content-type', 'application/json');
request.add(utf8.encode(json.encode(map)));
HttpClientResponse response = await request.close();
var responseBody = await response.transform(utf8.decoder).join();
Map jsonResponse = json.decode(responseBody);
print(jsonResponse);
if (response.statusCode == 200) {
if (jsonResponse['message'] ==
'200') { //if( jsonResponse['message'] == '200') {
setState(() {
_isLoading = false;
});
global.nameUser = jsonResponse['name'];
global.dataArea = jsonResponse['data_area'];
Navigator.pushReplacement(
context,
MaterialPageRoute(builder: (context) => UserPage()),
);
}
else {
Navigator.push(
context,
MaterialPageRoute(builder: (context) => Error_Auth()),
);
}
}
else {
setState(() {
_isLoading = false;
});
}
}
Container buttonSection() {
return Container(
width: MediaQuery.of(context).size.width,
height: 40.0,
padding: EdgeInsets.symmetric(horizontal: 15.0),
margin: EdgeInsets.only(top: 15.0),
child: RaisedButton(
onPressed: emailController.text == "" || passwordController.text == "" ? null : () {
setState(() {
_isLoading = true;
});
signIn(emailController.text, passwordController.text);
},
elevation: 0.0,
color: Colors.purple,
child: Text("Log in", style: TextStyle(color: Colors.white70)),
shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(5.0)),
),
);
}
final TextEditingController emailController = new TextEditingController();
final TextEditingController passwordController = new TextEditingController();
Container textSection() {
return Container(
padding: EdgeInsets.symmetric(horizontal: 15.0, vertical: 20.0),
child: Column(
children: <Widget>[
TextFormField(
controller: emailController,
cursorColor: Colors.white,
style: TextStyle(color: Colors.white70),
decoration: InputDecoration(
icon: Icon(Icons.login, color: Colors.white70),
hintText: "Name",
border: UnderlineInputBorder(borderSide: BorderSide(color: Colors.white70)),
hintStyle: TextStyle(color: Colors.white70),
),
),
SizedBox(height: 30.0),
TextFormField(
controller: passwordController,
cursorColor: Colors.white,
obscureText: true,
style: TextStyle(color: Colors.white70),
decoration: InputDecoration(
icon: Icon(Icons.lock, color: Colors.white70),
hintText: "Pass",
border: UnderlineInputBorder(borderSide: BorderSide(color: Colors.white70)),
hintStyle: TextStyle(color: Colors.white70),
),
),
],
),
);
}
Container headerSection() {
return Container(
alignment: Alignment.topCenter,
margin: EdgeInsets.only(top: 50.0),
child: Text("Пломби",
style: TextStyle(
color: Colors.white70,
fontSize: 40.0,
fontWeight: FontWeight.bold)),
);
}
}
class Error_Auth extends StatelessWidget {
@override
Widget build(BuildContext context) {
final AlertDialog dialog = AlertDialog(
title: Text('Помилка при авторизації'),
content:
Text('Повторити спробу авторизації'),
actions: [
FlatButton(
textColor: Color(0xFF6200EE),
onPressed: () => SystemNavigator.pop(),
child: Text('Ні'),
),
FlatButton(
textColor: Color(0xFF6200EE),
onPressed: () { Navigator.push(
context,MaterialPageRoute(builder: (context) => Login()),
);
},
child: Text('Так'),
),
],
);
return Scaffold(
body:dialog
);
}
}
class Storage {
Future<String> get localPath async {
final dir = await getApplicationDocumentsDirectory();
return dir.path;
}
Future<File> get localFile async {
final path = await localPath;
return File('$path/db.txt');
}
Future<String> readData() async {
try {
final file = await localFile;
String body = await file.readAsString();
return body;
} catch (e) {
return e.toString();
}
}
Future<File> writeData(String data) async {
final file = await localFile;
return file.writeAsString("$data");
}
}登录应用程序并转到用户页面后，导航菜单不会更新，只有2个图标可用。
解决方案1：将控制器传递到登录页面
List<Widget> tabPages = [];
@override
void initState() {
super.initState();
_pageController = PageController(initialPage: _pageIndex);
tabPages = [
Login(_pageController),
Setting(),
UserPage(),
Status_Obj(),
Status_seals(),
JsonParseAddSeals(),
];
}
而不是
Navigator.pushReplacement(
context,
MaterialPageRoute(builder: (context) => UserPage()),
);
使用
widget.pageController?.animateToPage(2,
duration: const Duration(milliseconds: 500), curve: Curves.easeInOut);
解决方案2：将控制器放入全局飞镖中。
顺便说一下，很酷的登录页面：-(