使用showdialog和textfield更新颤振中的单个Listview项
我们已经创建了一个Flitter应用程序,它可以从项目列表中显示listview。我们希望能够根据用户偏好更新这些。有点像如果你有一个待办事项列表,并且想使用模式或对话框来更正或更新列表中的一个项目 我一直试图用一个对话框更新listview中的一个项目,用户在该对话框中键入内容,然后在提交时关闭。到目前为止,我没有运气,但我觉得我很接近。如何在提交和重新呈现页面时更新互动程序上的名称?我错过了什么使用showdialog和textfield更新颤振中的单个Listview项,listview,flutter,mobile,dart,uitextfield,Listview,Flutter,Mobile,Dart,Uitextfield,我们已经创建了一个Flitter应用程序,它可以从项目列表中显示listview。我们希望能够根据用户偏好更新这些。有点像如果你有一个待办事项列表,并且想使用模式或对话框来更正或更新列表中的一个项目 我一直试图用一个对话框更新listview中的一个项目,用户在该对话框中键入内容,然后在提交时关闭。到目前为止,我没有运气,但我觉得我很接近。如何在提交和重新呈现页面时更新互动程序上的名称?我错过了什么 import 'package:flutter/material.dart'; void ma
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
List<Animal> animals = new List();
String newName;
TextEditingController nctrl = TextEditingController();
@override
void initState() {
super.initState();
animals = [
Animal(id: 1, name: 'cat'),
Animal(id: 2, name: 'dog'),
Animal(id: 3, name: 'mouse'),
Animal(id: 4, name: 'horse'),
Animal(id: 5, name: 'frog'),
];
}
_changePetName() {
newName = nctrl.text;
Navigator.pop(context);
return newName;
}
_showDialog(String name) {
nctrl.text = name;
showDialog(
context: context,
builder: (BuildContext context) {
// return object of type Dialog
return AlertDialog(
elevation: 5,
backgroundColor: Colors.blue,
title: Text(
"Rename this pet",
),
content: Container(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
TextField(
controller: nctrl,
onChanged: (e) {
setState(() {});
},
),
],
)),
actions: <Widget>[
// usually buttons at the bottom of the dialog
FlatButton(
child: Text("Close"),
onPressed: () {
Navigator.of(context).pop();
},
),
FlatButton(
color: Colors.green,
child: Text(
"Submit",
),
onPressed: () {
var updateName = _changePetName();
return updateName;
},
),
],
);
},
);
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
ListView.builder(
scrollDirection: Axis.vertical,
shrinkWrap: true,
itemCount: animals.length,
itemBuilder: (BuildContext context, int index) {
var pet = animals[index];
return ListTile(
key: ValueKey(pet.id),
enabled: true,
onTap: () async {
var rename = await _showDialog(pet.name);
if (rename != null) {
pet.name = rename;
setState(() {});
}
// setState(() {
// pet.name = 'bob';
// });
},
title: Text(pet.name),
);
},
),
],
),
),
);
}
}
class Animal {
final int id;
String name;
Animal({this.id, this.name});
factory Animal.fromJson(Map<dynamic, dynamic> json) {
return new Animal(
id: json['id'],
name: json['name'],
);
}
Map<dynamic, dynamic> toJson() {
final Map<dynamic, dynamic> data = new Map<dynamic, dynamic>();
data['id'] = this.id;
data['name'] = this.name;
return data;
}
}
导入“包装:颤振/材料.省道”;
void main()=>runApp(MyApp());
类MyApp扩展了无状态小部件{
@凌驾
小部件构建(构建上下文){
返回材料PP(
标题:“颤振演示”,
主题:主题数据(
主样本:颜色。蓝色,
),
主页:MyHomePage(标题:“颤振演示主页”),
);
}
}
类MyHomePage扩展StatefulWidget{
MyHomePage({Key,this.title}):超级(Key:Key);
最后的字符串标题;
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
列出动物=新列表();
字符串newName;
TextEditingController nctrl=TextEditingController();
@凌驾
void initState(){
super.initState();
动物=[
动物(id:1,名称:“猫”),
动物(id:2,名称:“狗”),
动物(id:3,名称:“老鼠”),
动物(id:4,名称:“马”),
动物(身份证号码:5,名字:“青蛙”),
];
}
_changePetName(){
newName=nctrl.text;
Navigator.pop(上下文);
返回newName;
}
_showDialog(字符串名称){
nctrl.text=名称;
显示对话框(
上下文:上下文,
生成器:(BuildContext上下文){
//返回对话框类型的对象
返回警报对话框(
标高:5,
背景颜色:Colors.blue,
标题:正文(
“重命名此宠物”,
),
内容:容器(
子:列(
mainAxisSize:mainAxisSize.min,
儿童:[
文本字段(
控制员:nctrl,
一旦更改:(e){
setState((){});
},
),
],
)),
行动:[
//通常是对话框底部的按钮
扁平按钮(
子项:文本(“关闭”),
已按下:(){
Navigator.of(context.pop();
},
),
扁平按钮(
颜色:颜色。绿色,
子:文本(
“提交”,
),
已按下:(){
var updateName=_changePetName();
返回updateName;
},
),
],
);
},
);
}
@凌驾
小部件构建(构建上下文){
返回脚手架(
appBar:appBar(
标题:文本(widget.title),
),
正文:中(
子:列(
mainAxisAlignment:mainAxisAlignment.center,
儿童:[
ListView.builder(
滚动方向:轴垂直,
收缩膜:对,
itemCount:animals.length,
itemBuilder:(构建上下文,int索引){
var pet=动物[指数];
返回列表块(
密钥:ValueKey(宠物id),
启用:对,
onTap:()异步{
var rename=wait_showDialog(pet.name);
如果(重命名!=null){
pet.name=重命名;
setState((){});
}
//设置状态(){
//pet.name='bob';
// });
},
标题:文本(宠物名称),
);
},
),
],
),
),
);
}
}
类动物{
最终int id;
字符串名;
动物({this.id,this.name});
factory Animal.fromJson(映射json){
归还新动物(
id:json['id'],
名称:json['name'],
);
}
映射到JSON(){
最终地图数据=新地图();
数据['id']=this.id;
数据['name']=this.name;
返回数据;
}
}
在Onpress警报方法对话框中,只需粘贴此代码
Navigator.pushReplacement(
context,
MaterialPageRoute(builder: (_) => MyHomePage()));
我们会将您的页面导航到相同的位置。一些更正将使您的代码正常工作:
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
List<Animal> animals = new List();
String newName;
TextEditingController nctrl = TextEditingController();
@override
void initState() {
super.initState();
animals = [
Animal(id: 1, name: 'cat'),
Animal(id: 2, name: 'dog'),
Animal(id: 3, name: 'mouse'),
Animal(id: 4, name: 'horse'),
Animal(id: 5, name: 'frog'),
];
}
_changePetName() {
newName = nctrl.text;
Navigator.pop(context, newName);
return newName;
}
Future<String> _showDialog(String name) async {
nctrl.text = name;
return await showDialog<String>(
context: context,
builder: (BuildContext context) {
// return object of type Dialog
return AlertDialog(
elevation: 5,
backgroundColor: Colors.blue,
title: Text(
"Rename this pet",
),
content: Container(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
TextField(
controller: nctrl,
onChanged: (e) {
// setState(() {});
},
),
],
)),
actions: <Widget>[
// usually buttons at the bottom of the dialog
FlatButton(
child: Text("Close"),
onPressed: () {
Navigator.of(context).pop(nctrl.text);
},
),
FlatButton(
color: Colors.green,
child: Text(
"Submit",
),
onPressed: () {
var updateName = _changePetName();
return updateName;
},
),
],
);
},
);
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
ListView.builder(
scrollDirection: Axis.vertical,
shrinkWrap: true,
itemCount: animals.length,
itemBuilder: (BuildContext context, int index) {
var pet = animals[index];
return ListTile(
key: ValueKey(pet.id),
enabled: true,
onTap: () async {
var rename = await _showDialog(pet.name);
if (rename != null) {
pet.name = rename;
setState(() {});
}
// setState(() {
// pet.name = 'bob';
// });
},
title: Text(pet.name),
);
},
),
],
),
),
);
}
}
class Animal {
final int id;
String name;
Animal({this.id, this.name});
factory Animal.fromJson(Map<dynamic, dynamic> json) {
return new Animal(
id: json['id'],
name: json['name'],
);
}
Map<dynamic, dynamic> toJson() {
final Map<dynamic, dynamic> data = new Map<dynamic, dynamic>();
data['id'] = this.id;
data['name'] = this.name;
return data;
}
}
导入“包装:颤振/材料.省道”;
void main()=>runApp(MyApp());
类MyApp扩展了无状态小部件{
@凌驾
小部件构建(构建上下文){
返回材料PP(
标题:“颤振演示”,
主题:主题数据(
主样本:颜色。蓝色,
),
主页:MyHomePage(标题:“颤振演示主页”),
);
}
}
类MyHomePage扩展StatefulWidget{
MyHomePage({Key,this.title}):超级(Key:Key);
最后的字符串标题;
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
列出动物=新列表();
字符串newName;
TextEditingController nctrl=TextEditingController();
@凌驾
void initState(){
super.initState();
动物=[
动物(id:1,名称:“猫”),
动物(id:2,名称:“狗”),
动物(id:3,名称:“老鼠”),
动物(id:4,名称:“马”),
动物(身份证号码:5,名字:“青蛙”),
];
}
_changePetName(){
newName=nctrl.text;
pop(上下文,newName);
返回newName;
}
Future\u showDialog(字符串名称)异步{
nctrl.text=名称;
返回等待显示对话框(
上下文:上下文,
别伊
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
List<Animal> animals = new List();
String newName;
TextEditingController nctrl = TextEditingController();
@override
void initState() {
super.initState();
animals = [
Animal(id: 1, name: 'cat'),
Animal(id: 2, name: 'dog'),
Animal(id: 3, name: 'mouse'),
Animal(id: 4, name: 'horse'),
Animal(id: 5, name: 'frog'),
];
}
_showDialog(int index) {
nctrl.text = animals[index].name;
showDialog(
context: context,
builder: (BuildContext context) {
// return object of type Dialog
return AlertDialog(
elevation: 5,
backgroundColor: Colors.blue,
title: Text(
"Rename this pet",
),
content: Container(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
TextField(
controller: nctrl,
onChanged: (e) {
setState(() {});
},
),
],
)),
actions: <Widget>[
// usually buttons at the bottom of the dialog
FlatButton(
child: Text("Close"),
onPressed: () {
Navigator.of(context).pop();
},
),
FlatButton(
color: Colors.green,
child: Text(
"Submit",
),
onPressed: () {
setState(() {
animals[index].name = nctrl.text;
});
Navigator.pop(context);
},
),
],
);
},
);
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
ListView.builder(
scrollDirection: Axis.vertical,
shrinkWrap: true,
itemCount: animals.length,
itemBuilder: (BuildContext context, int index) {
var pet = animals[index];
return ListTile(
key: ValueKey(pet.id),
enabled: true,
onTap: () async {
var rename = await _showDialog(index);
if (rename != null) {
animals[index].name = rename;
setState(() {});
}
// setState(() {
// pet.name = 'bob';
// });
},
title: Text(pet.name),
);
},
),
],
),
),
);
}
}
class Animal {
final int id;
String name;
Animal({this.id, this.name});
factory Animal.fromJson(Map<dynamic, dynamic> json) {
return new Animal(
id: json['id'],
name: json['name'],
);
}
Map<dynamic, dynamic> toJson() {
final Map<dynamic, dynamic> data = new Map<dynamic, dynamic>();
data['id'] = this.id;
data['name'] = this.name;
return data;
}
}