Flutter listview不使用setState更新
我有一张卡片,上面有一个TexField和一个选择图像的按钮。 选择图像后,必须将图标替换为图像,并且在选择对话框中必须显示“删除”项。 它在第一张固定的卡上工作得很好,但在Listview中动态插入的卡上,它不工作,因为它不使用setState更新。 如何更新listViewFlutter listview不使用setState更新,flutter,listview,setstate,Flutter,Listview,Setstate,我有一张卡片,上面有一个TexField和一个选择图像的按钮。 选择图像后,必须将图标替换为图像,并且在选择对话框中必须显示“删除”项。 它在第一张固定的卡上工作得很好,但在Listview中动态插入的卡上,它不工作,因为它不使用setState更新。 如何更新listView import 'package:flutter/material.dart'; import 'dart:io'; import 'package:image_picker/image_picker.dart'; imp
import 'package:flutter/material.dart';
import 'dart:io';
import 'package:image_picker/image_picker.dart';
import 'package:image_cropper/image_cropper.dart';
void main() => runApp(MaterialApp(
home: NewPollPage(),
));
class NewPollPage extends StatefulWidget {
@override
_NewPollPageState createState() => _NewPollPageState();
}
class _NewPollPageState extends State<NewPollPage> {
Map photoMap = {};
var cards = <Card>[];
var newAlt = <TextEditingController>[];
var alternativaController = TextEditingController();
var alternativa1Controller = TextEditingController();
String indice = UniqueKey().toString();
File cropped;
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.black,
title: Text('Cards'),
centerTitle: true,
),
body: SingleChildScrollView(
child: Column(
children: [
Card(
elevation: 0,
color: Color(0xFAFAFA),
child: Row(
children: [
!photoMap.containsKey('foto_n1')
? IconButton(
padding: EdgeInsets.only(bottom: 18.0),
icon: Icon(Icons.camera_alt),
color: Colors.black,
onPressed: () {
setState(() {
selectImage(context, 'n1', false);
});
},
)
: GestureDetector(
child: Container(
padding: EdgeInsets.only(bottom: 20.0),
width: 50,
height: 46,
child: Image.file(photoMap['foto_n1']),
),
onTap: () {
setState(() {
selectImage(context, 'n1', true);
});
},
),
Expanded(
child: TextField(
controller: alternativa1Controller,
maxLength: 60,
decoration: InputDecoration(
hintText: 'Digite a alternativa',
contentPadding: EdgeInsets.only(left: 12, top: 22),
fillColor: Color(0xFFE3E4E8),
filled: true,
border: OutlineInputBorder(
borderSide: BorderSide.none,
borderRadius: BorderRadius.circular(25.0),
),
),
),
),
],
),
),
ListView.builder(
shrinkWrap: true,
physics: NeverScrollableScrollPhysics(),
itemCount: cards.length,
itemBuilder: (context, index) {
indice = UniqueKey().toString();
return cards[index];
},
)
],
),
),
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
backgroundColor: Colors.black,
onPressed: () {
setState(() => cards.add(createCard(indice)));
},
),
);
}
Card createCard(indice) {
var alternativaController = TextEditingController();
newAlt.add(alternativaController);
return Card(
elevation: 0,
color: Color(0xFAFAFA),
child: Row(
children: [
!photoMap.containsKey('foto_$indice')
? IconButton(
padding: EdgeInsets.only(bottom: 18.0),
icon: Icon(Icons.camera_alt),
color: Colors.black,
onPressed: () {
setState(() {
selectImage(context, '$indice', false);
});
},
)
: GestureDetector(
child: Container(
padding: EdgeInsets.only(bottom: 20.0),
width: 50,
height: 46,
child: Image.file(photoMap['foto_$indice']),
),
onTap: () {
setState(() {
selectImage(context, '$indice', true);
});
},
),
Expanded(
child: TextField(
maxLength: 60,
decoration: InputDecoration(
hintText: 'Digite a alternativa',
contentPadding: EdgeInsets.only(left: 12, top: 22),
fillColor: Color(0xFFE3E4E8),
filled: true,
border: OutlineInputBorder(
borderSide: BorderSide.none,
borderRadius: BorderRadius.circular(25.0),
),
),
),
),
],
),
);
}
selectImage(parentContext, indice, visivel) {
return showDialog(
context: context,
builder: (context) {
return SimpleDialog(
title: Text('Selecione:'),
children: [
if (photoMap.containsKey('foto_$indice'))
Image.file(photoMap['foto_$indice']),
SimpleDialogOption(
child: Row(
children: [
Icon(Icons.camera_alt),
Text(' Tirar foto com a câmera'),
],
),
onPressed: () => getImage(ImageSource.camera, indice)),
SimpleDialogOption(
child: Row(
children: [
Icon(Icons.photo_library),
Text(' Foto da galeria'),
],
),
onPressed: () => getImage(ImageSource.gallery, indice)),
Visibility(
visible: visivel,
child: SimpleDialogOption(
child: Row(
children: [
Icon(Icons.delete),
Text(' Apagar'),
],
),
onPressed: () => null //apagarFoto(mapa),
),
),
SimpleDialogOption(
child: Row(
children: [
Icon(Icons.cancel),
Text(' Cancelar'),
],
),
onPressed: () => Navigator.pop(context),
)
],
);
});
}
Future getImage(ImageSource source, indice) async {
Navigator.pop(context);
PickedFile imagePicker = await ImagePicker().getImage(source: source);
if (imagePicker != null) {
cropped = await ImageCropper.cropImage(
sourcePath: imagePicker.path,
aspectRatio: CropAspectRatio(ratioX: 4, ratioY: 3),
compressQuality: 70,
maxWidth: 700,
maxHeight: 700,
compressFormat: ImageCompressFormat.jpg,
androidUiSettings: AndroidUiSettings(
toolbarColor: Colors.black,
toolbarTitle: "Foto",
statusBarColor: Colors.black,
backgroundColor: Colors.black,
toolbarWidgetColor: Colors.white,
dimmedLayerColor: Colors.black,
),
);
if (cropped != null) {
setState(() {
photoMap['foto_$indice'] = cropped;
});
}
}
}
}
导入“包装:颤振/材料.省道”;
导入“dart:io”;
导入“包:image_picker/image_picker.dart”;
导入“package:image_cropper/image_cropper.dart”;
void main()=>runApp(MaterialApp(
主页:NewPollPage(),
));
类NewPollPage扩展StatefulWidget{
@凌驾
_NewPollPageState createState();
}
类_NewPollPageState扩展状态{
Map photoMap={};
var卡=[];
var newAlt=[];
var alternativaController=TextEditingController();
var alternativa1Controller=TextEditingController();
字符串标识=UniqueKey().toString();
文件裁剪;
@凌驾
小部件构建(构建上下文){
返回脚手架(
appBar:appBar(
背景颜色:Colors.black,
标题:文本(“卡片”),
标题:对,
),
正文:SingleChildScrollView(
子:列(
儿童:[
卡片(
海拔:0,
颜色:颜色(0xFAFAFA),
孩子:排(
儿童:[
!photoMap.containsKey('foto_n1'))
?图标按钮(
填充:仅限边缘设置(底部:18.0),
图标:图标(Icons.camera\u alt),
颜色:颜色,黑色,
已按下:(){
设置状态(){
选择图像(上下文“n1”,false);
});
},
)
:手势检测器(
子:容器(
填充:仅限边缘设置(底部:20.0),
宽度:50,
身高:46,
子:Image.file(photoMap['foto_n1']),
),
onTap:(){
设置状态(){
选择图像(上下文“n1”,true);
});
},
),
扩大(
孩子:TextField(
控制器:Alternativa1控制器,
最大长度:60,
装饰:输入装饰(
hintText:“Digite a alternativa”,
contentPadding:仅限边集(左:12,顶:22),
填充颜色:颜色(0xFFE3E4E8),
是的,
边框:大纲输入边框(
borderSide:borderSide.none,
边界半径:边界半径。圆形(25.0),
),
),
),
),
],
),
),
ListView.builder(
收缩膜:对,
物理学:NeverscrollableScroll物理学(),
itemCount:cards.length,
itemBuilder:(上下文,索引){
indice=UniqueKey().toString();
返回卡[索引];
},
)
],
),
),
浮动操作按钮:浮动操作按钮(
子:图标(Icons.add),
背景颜色:Colors.black,
已按下:(){
设置状态(()=>cards.add(createCard(indice));
},
),
);
}
卡片创建卡片(标识){
var alternativaController=TextEditingController();
newAlt.add(可选控件);
回程卡(
海拔:0,
颜色:颜色(0xFAFAFA),
孩子:排(
儿童:[
!photoMap.containsKey('foto_u$indice')
?图标按钮(
填充:仅限边缘设置(底部:18.0),
图标:图标(Icons.camera\u alt),
颜色:颜色,黑色,
已按下:(){
设置状态(){
选择图像(上下文,$indice',false);
});
},
)
:手势检测器(
子:容器(
填充:仅限边缘设置(底部:20.0),
宽度:50,
身高:46,
子:Image.file(photoMap['foto_u$indice']),
),
onTap:(){
设置状态(){
选择图像(上下文,$indice',true);
});
},
),
扩大(
孩子:TextField(
最大长度:60,
装饰:输入装饰(
hintText:“Digite a alternativa”,
contentPadding:仅限边集(左:12,顶:22),
填充颜色:颜色(0xFFE3E4E8),
是的,
边框:大纲输入边框(
borderSide:borderSide.none,
边界半径:边界半径。圆形(25.0),
),
),
),
),
],
),
);
}
选择图像(父上下文、标识、访问级别){
返回显示对话框(
上下文:上下文,
生成器:(上下文){
返回SimpleDialog(
标题:文本('Selecione:'),
儿童:[
if(影像地图容器('foto_u$indice'))
Image.file(photoMap['foto_u$indice']),
简单幻觉(
孩子:排(
儿童:[
图标(Icons.camera)_
ListView.builder(
shrinkWrap: true,
physics: NeverScrollableScrollPhysics(),
itemCount: cards.length,
itemBuilder: (context, index) {
indice = UniqueKey().toString();
return cards[index];
},
)
ListView.builder(
shrinkWrap: true,
physics: NeverScrollableScrollPhysics(),
itemCount: photoMap.length,
itemBuilder: (context, index) {
return _cardWidget(index);
},
)
Card _cardWidget(int index) {
return Card(
elevation: 0,
color: Color(0xFAFAFA),
child: Row(
children: [
photoMap['foto_$index'] == ''
? IconButton(
padding: EdgeInsets.only(bottom: 18.0),
icon: Icon(Icons.camera_alt),
color: Colors.black,
onPressed: () {
setState(() {
selectImage(context, '$index', false);
});
},
)
: GestureDetector(
child: Container(
padding: EdgeInsets.only(bottom: 20.0),
width: 50,
height: 46,
child: Image.file(photoMap['foto_$index']),
),
onTap: () {
setState(() {
selectImage(context, '$index', true);
});
},
),
Expanded(
child: TextField(
maxLength: 60,
decoration: InputDecoration(
hintText: 'Digite a alternativa',
contentPadding: EdgeInsets.only(left: 12, top: 22),
fillColor: Color(0xFFE3E4E8),
filled: true,
border: OutlineInputBorder(
borderSide: BorderSide.none,
borderRadius: BorderRadius.circular(25.0),
),
),
),
),
],
),
);
}
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
backgroundColor: Colors.black,
onPressed: () {
setState(() => photoMap["foto_${photoMap.length}"] = '');
},
),
if (photoMap['foto_$indice'] != '')Image.file(photoMap['foto_$indice']),