flutter - 我正在制作通讯录应用程序，但是当我保存联系人时，未显示姓名
问题描述
这是我的联系人列表页面
class Contacts extends StatefulWidget with NavigationStates {
@override
_ContactsState createState() => _ContactsState();
}
class _ContactsState extends State<Contacts>{
DatabaseHelper databaseHelper = DatabaseHelper();
List<contacts> contactsList;
int count = 0;
@override
Widget build(BuildContext context, ) {
if(contactsList == 0){
contactsList = List<contacts>();
updateListView();
}
return Scaffold(
resizeToAvoidBottomPadding: false,
appBar: AppBar(
title: Text("Contacts"),
backgroundColor: Colors.lightGreenAccent,
centerTitle: true,
),
body: Column(
children: <Widget>[
Container(
padding: EdgeInsets.all(4.0),
margin: EdgeInsets.all(5.0),
child: TextField(
//controller: searchController,
decoration: InputDecoration(
labelText:'Search Contacts',
border: new OutlineInputBorder(
borderRadius: BorderRadius.all(Radius.circular(25)),
borderSide: new BorderSide(
color: Colors.pinkAccent
)
),
prefixIcon: Icon(
Icons.search,
color: Colors.black,
)
),
),
),
Expanded(
child: ListView.builder(
itemCount: count,
itemBuilder: (context , int position){
return Card(
elevation: 1.0,
shape: RoundedRectangleBorder(
side: BorderSide(color: Colors.pinkAccent,width: 1),
borderRadius: BorderRadius.circular(20)
),
child: Container(
margin: EdgeInsets.all(6.0),
padding: EdgeInsets.all(4.0),
color: Colors.white,
child: ListTile(
leading: CircleAvatar(
radius: 30.0,
backgroundColor: Colors.lightBlueAccent,
child: Icon(Icons.person,color: Colors.black,),
),
title: Text(this.contactsList[position].first_name,style: TextStyle(color: Colors.black,fontSize: 28.0),),
subtitle: Text(this.contactsList[position].last_name,style:TextStyle(color: Colors.black38,fontSize: 15.0),),
trailing: GestureDetector(
child: Icon(Icons.delete, color: Colors.pinkAccent,),
onTap: () {
_delete(context, contactsList[position]);
},
),
),
),
);
},
),
)
],
),
floatingActionButton: new FloatingActionButton(onPressed: null,
child: new Icon(Icons.dialpad,color: Colors.black,size: 30,),
backgroundColor: Colors.pinkAccent,
),
bottomNavigationBar: CurvedNavigationBar(
color: Colors.lightGreenAccent,
backgroundColor: Colors.white,
buttonBackgroundColor: Colors.pinkAccent,
height: 50,
index: 1,
items:<Widget>[
Icon(Icons.call,size: 25,color: Colors.black,),
Icon(Icons.home,size: 30,color: Colors.black,),
Icon(Icons.person_add_rounded,size: 25,color: Colors.black,),
],
animationDuration: Duration(
milliseconds: 400
),
animationCurve: Curves.easeIn,
onTap: (index) async {
if (index == 0)
Navigator.of(context).push(
MaterialPageRoute(
builder: (BuildContext context) {
return logs();
}
)
);
if (index == 1)
Navigator.of(context).push(
MaterialPageRoute(
builder: (BuildContext context) {
return Contacts();
}
)
);
if (index == 2)
navigateToDetail(contacts('',''));
}
),
);
}
updateListView() {
final Future<Database> dbFuture = databaseHelper.initalizeDatabase();
dbFuture.then((database) {
Future<List<contacts>> contactsListFuture = databaseHelper.getContactList();
contactsListFuture.then((contactsList){
setState(() {
this.contactsList = contactsList;
this.count = contactsList.length;
});
});
});
}
Color getStorageColor() {
int storage;
switch (storage) {
case 1:
return Colors.pinkAccent;
break;
case 2:
return Colors.lightBlueAccent;
break;
default:
return Colors.lightBlueAccent;
}
}
void navigateToDetail(contacts contact) async{
bool result = await Navigator.push(context, MaterialPageRoute(builder: (context) {
return AddContacts(contact);
}));
if (result == true) {
updateListView();
}
}
void _delete(BuildContext context, contacts contact) async {
int result = await databaseHelper.deleteContact(contact.id);
if (result != 0) {
_SnackBar(context, 'Contact Deleted Successfully');
updateListView();
}
}
void _SnackBar(BuildContext context, String message) {
final snackBar = SnackBar(
content: Text(message),
action: SnackBarAction(
label: 'Undo',
onPressed: (){},
),
);
// ignore: deprecated_member_use
Scaffold.of(context).showSnackBar(snackBar);
}
}
这是我的联系人详细信息页面
import 'dart:io';
//import 'package:contacts_service/contacts_service.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
//import 'package:sqflite/sqflite.dart';
import 'package:mycontacts_app/models/Contact.dart';
import 'dart:async';
import 'package:mycontacts_app/utils/database_helper.dart';
//import 'package:intl/intl.dart';
class AddContacts extends StatefulWidget {
final contacts contact;
AddContacts(this.contact);
//AddContacts(contacts contact);
@override
State<StatefulWidget> createState() {
// _AddContactsState();
return _AddContactsState(this.contact);
}
}
class _AddContactsState extends State<AddContacts> {
//TextEditingController _fnameController,_numberController,_lnameController;
DatabaseHelper helper = DatabaseHelper();
PickedFile _imageFile;
final ImagePicker _picker = ImagePicker();
_AddContactsState(this.contact);
TextEditingController _fnameController = TextEditingController();
TextEditingController _numberController = TextEditingController();
TextEditingController _lnameController = TextEditingController();
contacts contact;
List _Storage = ['Phone','Sim'];
//String _storageval;
@override
Widget build(BuildContext context) {
//_nameController = contacts.first_name
_fnameController.text = contact.first_name;
_lnameController.text = contact.last_name;
_numberController.text = contact.phone_no as String;
return Scaffold(
appBar: AppBar(
title: Text("New Contact"),
backgroundColor: Colors.lightGreenAccent,
centerTitle: true,
),
body: SingleChildScrollView(
child: Container(
padding: EdgeInsets.symmetric(
vertical: 40.0,
horizontal: 10.0,
),
//margin: EdgeInsets.all(15),
child: Form(
child: Column(
//crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(16.0),
child: Container(
padding: EdgeInsets.only(left: 16.0,right: 16.0),
decoration: BoxDecoration(
border: Border.all(
color: Colors.white
),
borderRadius: BorderRadius.circular(20.0),
),
child: DropdownButton(
hint: Text('Store In '),
dropdownColor: Colors.black12,
elevation: 5,
icon: Icon(Icons.arrow_drop_down),
iconSize: 20.0,
isExpanded: true,
style: TextStyle(
color: Colors.black,fontSize: 18.0
),
items: _Storage.map((value){
return DropdownMenuItem(
value: value,
child: Text(value),
);
}).toList(),
value: getStorageAsString(contact.storage),
onChanged: (value){
setState(() {
//_storageval = value;
updateStorageAsInt(value);
});
},
),
),
),
imageProfile(),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
controller: _fnameController,
onChanged: (value){
updateFirstname();
},
decoration: InputDecoration(
hintText: 'First Name',
prefixIcon: Icon(Icons.person),
//prefixText: "Name",
suffixIcon: Icon(Icons.keyboard_arrow_down),
fillColor: Colors.white,
filled: true,
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(20.0),
),
contentPadding: EdgeInsets.all(15),
),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
controller: _lnameController,
onChanged: (value){
updateLastName();
},
decoration: InputDecoration(
hintText: 'Last Name',
prefixIcon: Icon(Icons.person),
//prefixText: "Name",
//suffixIcon: Icon(Icons.keyboard_arrow_down),
fillColor: Colors.white,
filled: true,
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(20.0),
),
contentPadding: EdgeInsets.all(15),
),
),
),
// SizedBox(height: 15),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
controller: _numberController,
onChanged: (value){
//updateNumber();
},
decoration: InputDecoration(
hintText: 'Number',
prefixIcon: Icon(Icons.phone_android),
//prefixText: "Name",
//suffixIcon: Icon(Icons.keyboard_arrow_down),
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(20.0),
),
fillColor: Colors.white,
filled: true,
contentPadding: EdgeInsets.all(15),
),
),
),
//SizedBox(height: 15),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
//controller: _nameController,
decoration: InputDecoration(
hintText: 'Address',
prefixIcon: Icon(Icons.location_on_rounded),
//prefixText: "Name",
suffixIcon: Icon(Icons.keyboard_arrow_down),
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(20.0),
),
fillColor: Colors.white,
filled: true,
contentPadding: EdgeInsets.all(15),
),
),
),
//SizedBox(height: 15),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
//controller: _nameController,
decoration: InputDecoration(
hintText: 'Email',
prefixIcon: Icon(Icons.email),
//prefixText: "Name",
//suffixIcon: Icon(Icons.keyboard_arrow_down),
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(20.0),
),
fillColor: Colors.white,
filled: true,
contentPadding: EdgeInsets.all(15),
),
),
),
//SizedBox(height: 15),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
//controller: _nameController,
decoration: InputDecoration(
hintText: 'Website',
prefixIcon: Icon(Icons.language),
//prefixText: "Name",
//suffixIcon: Icon(Icons.keyboard_arrow_down),
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(20.0),
),
fillColor: Colors.white,
filled: true,
contentPadding: EdgeInsets.all(15),
),
),
),
//SizedBox(height: 15),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
//controller: _nameController,
decoration: InputDecoration(
hintText: 'Work Info',
prefixIcon: Icon(Icons.business),
//prefixText: "Name",
//suffixIcon: Icon(Icons.keyboard_arrow_down),
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(20.0),
),
fillColor: Colors.white,
filled: true,
contentPadding: EdgeInsets.all(15),
),
),
),
/*ListView.builder(
itemBuilder: (context, index){
return ExpansionTile(
title: ListTile(
title: TextField(
decoration: InputDecoration(
hintText: "Name"
),
style: TextStyle(
color: Colors.black,
fontSize: 15.0,
),
),
),
children: <Widget>[
ListTile(
title:TextFormField(
decoration: InputDecoration(
hintText: "Name Prefix"
),
)
),
ListTile(
title:TextFormField(
decoration: InputDecoration(
hintText: " First Name"
),
)
),
ListTile(
title:TextFormField(
decoration: InputDecoration(
hintText: " Middle Name"
),
)
),
ListTile(
title:TextFormField(
decoration: InputDecoration(
hintText: "Last Name"
),
)
),
ListTile(
title:TextFormField(
decoration: InputDecoration(
hintText: "Name Suffix"
),
)
)
],
);
}
)*/
Padding(
padding: const EdgeInsets.only(top: 15.0, bottom: 15.0),
child: Row(
children: <Widget>[
Expanded(
child: RaisedButton(
color: Colors.lightGreenAccent,
textColor: Colors.black,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(18.0),
side: BorderSide(color: Colors.pinkAccent),
),
onPressed: () {
debugPrint("Save button clicked");
_save();
},
child: Text(
"Save"
),
),
),
Container(width: 5.0,),
Expanded(
child: RaisedButton(
color: Colors.lightGreenAccent,
textColor: Colors.black,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(18.0),
side: BorderSide(color: Colors.pinkAccent),
),
onPressed: () {
_delete();
},
child: Text(
"Cancel"
),
),
)
],
),
)
],
),
),
),
),
);
}
Widget imageProfile() {
return Center(
child: Stack(
children: <Widget>[
CircleAvatar(
radius: 50.0,
backgroundImage: _imageFile==null? AssetImage("assets/default.png"):FileImage(File(_imageFile.path)),
),
Positioned(
bottom: 20.0,
right: 20.0,
child: InkWell(
onTap: () {
showModalBottomSheet(
context: context,
builder: ((builder) => bottomSheet()),
);
},
child: Icon(
Icons.camera_alt,
color: Colors.lightGreenAccent,
size: 28.0,
),
),
),
],
),
);
}
Widget bottomSheet() {
return Container(
height: 100.0,
width: MediaQuery.of(context).size.width,
margin: EdgeInsets.symmetric(
horizontal: 20,
vertical: 20,
),
child: Column(
children: <Widget>[
Text(
"Choose Contact Image",
style: TextStyle(
fontSize: 20,
),
),
SizedBox(
height: 20,
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
FlatButton.icon(
icon: Icon(Icons.camera),
onPressed: (){
takePhoto(ImageSource.camera);
},
label: Text("Camera"),
),
FlatButton.icon(
icon: Icon(Icons.image),
onPressed: (){
takePhoto(ImageSource.gallery);
},
label: Text("Gallery"),
)
],
)
],
),
);
}
void takePhoto(ImageSource source) async {
final pickedFile = await _picker.getImage(
source: source,
);
setState(() {
_imageFile = pickedFile;
});
}
void updateFirstname(){
contact.first_name = _fnameController.text;
}
// Update the description of Note object
void updateLastName() {
contact.last_name = _lnameController.text;
}
/*void updateNumber() {
contact.phone_no = _numberController.text as int;
}*/
void _save() async {
moveToLastScreen();
//n.date = DateFormat.yMMMd().format(DateTime.now());
int result;
if (contact.id != null) { // Case 1: Update operation
result = await helper.updateContact(contact);
} else { // Case 2: Insert Operation
result = await helper.insertContact(contact);
}
if (result != 0) { // Success
_showAlertDialog('Status', 'Contact Saved Successfully');
} else { // Failure
_showAlertDialog('Status', 'Problem Saving Contact');
}
}
void moveToLastScreen() {
//Navigator.pop(context);
Navigator.pop(context, true);
}
void _delete() async {
moveToLastScreen();
// Case 1: If user is trying to delete the NEW NOTE i.e. he has come to
// the detail page by pressing the FAB of NoteList page.
if (contact.id == null) {
_showAlertDialog('Status','No Contact was deleted');
return;
}
// Case 2: User is trying to delete the old note that already has a valid ID.
int result = await helper.deleteContact(contact.id);
if (result != 0) {
_showAlertDialog('Status','Contact Deleted Successfully');
} else {
_showAlertDialog('Status', 'Error Occured while Deleting Contact');
}
}
void _showAlertDialog(String title, String message) {
AlertDialog alertDialog = AlertDialog(
title: Text(title),
content: Text(message),
);
showDialog(
context: context,
builder: (_) => alertDialog
);
}
void updateStorageAsInt(String value) {
switch (value) {
case 'Phone':
contact.storage = 1;
break;
case 'Sim':
contact.storage = 2;
break;
}
}
// Convert int priority to String priority and display it to user in DropDown
String getStorageAsString(int value) {
String storage;
switch (value) {
case 1:
storage = _Storage[0]; // 'High'
break;
case 2:
storage = _Storage[1]; // 'Low'
break;
}
return storage;
}
}
显示联系人卡片和图标，但未显示姓名。
我什至收到如下错误：- 此小部件已被卸载，因此 State 不再具有上下文（应被视为已失效）。
它甚至没有显示错误的位置或文件而且我无法解决错误。
解决方案
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