Flutter 使用一个集团,一个国家的页面分割形式?
我有一个单一表单,根据用户体验和用户界面设计要求将其分为3页。结构如下所示:Flutter 使用一个集团,一个国家的页面分割形式?,flutter,bloc,flutter-bloc,Flutter,Bloc,Flutter Bloc,我有一个单一表单,根据用户体验和用户界面设计要求将其分为3页。结构如下所示: MyApp | |- BlocProvider.of<MyBloc>(context) |- PageA | |- FormA | |- InputA | |- InputB | |- InputC | |- RaisedButton (Next button
MyApp
|
|- BlocProvider.of<MyBloc>(context)
|- PageA
| |- FormA
| |- InputA
| |- InputB
| |- InputC
| |- RaisedButton (Next button)
|
|- PageB
| |- FormA
| |- InputD
| |- InputE
| |- InputF
| |- RaisedButton (Back button)
| |- RaisedButton (Next button)
|
|- PageC
| |- FormA
| |- InputG
| |- InputH
| |- InputI
| |- RaisedButton (Back button)
| |- RaisedButton (Submit button)
MyApp
|
|-BlocProvider.of(上下文)
|-佩加
||-形式
||-输入
||-输入b
||-InputC
||-升起按钮(下一个按钮)
|
|-PageB
||-形式
||-输入
||-输入
||-输入
||-升起按钮(后退按钮)
||-升起按钮(下一个按钮)
|
|-佩奇
||-形式
||-输入
||-InputH
||-InputI
||-升起按钮(后退按钮)
||-升起按钮(提交按钮)
我希望传递相同的状态,并更新RaisedButton
按钮的状态数据onPressed
,而无需将我的树包装在blocbuilder、bloclistener
或blocconsumer
中,因为不需要在状态更改时重建小部件
我该怎么做
注意
- 每个表单都是一个页面,而不是选项卡栏或页面视图
- 我只希望在整个页面上共享一个bloc和一个state,而不是每页共享一个bloc
- 我想要这种行为仅仅是因为我实际上避免了从构造函数传递数据
- 已尝试
,但它不允许我访问该对象BlocProvider.of(context).state
我举了一个很简单的例子,希望能对你有所帮助
import 'package:equatable/equatable.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return BlocProvider(
create: (_) => MyForm(),
child: MaterialApp(
title: 'Flutter Demo',
home: HomePage(),
),
);
}
}
class HomePage extends StatelessWidget {
Widget build(BuildContext context) {
return Scaffold(
body: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
BlocBuilder<MyForm, MyFromState>(
builder: (_, state) {
return Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Text('inputA: ${state.inputA}'),
Text('inputB: ${state.inputB}'),
Text('inputC: ${state.inputC}'),
Text('inputD: ${state.inputD}'),
Text('inputE: ${state.inputE}'),
Text('inputF: ${state.inputF}'),
],
);
},
),
Center(
child: RaisedButton(
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(builder: (context) => FirstPage()),
);
},
child: Text('start'),
),
),
],
),
);
}
}
class FirstPage extends StatelessWidget {
Widget build(BuildContext context) {
var bloc = BlocProvider.of<MyForm>(context);
return Scaffold(
body: Center(
child: RaisedButton(
onPressed: () {
bloc.add(FirstPageSubmitEvent(
inputA: 'text1',
inputB: 'text2',
));
Navigator.push(
context,
MaterialPageRoute(builder: (context) => SecondPage()),
);
},
child: Text('page 2'),
),
),
);
}
}
class SecondPage extends StatelessWidget {
Widget build(BuildContext context) {
var bloc = BlocProvider.of<MyForm>(context);
return Scaffold(
body: Center(
child: RaisedButton(
onPressed: () {
bloc.add(SecondPageSubmitEvent(
inputC: 'text3',
inputD: 'text4',
));
Navigator.push(
context,
MaterialPageRoute(builder: (context) => ThirdPage()),
);
},
child: Text('page 3'),
),
),
);
}
}
class ThirdPage extends StatelessWidget {
Widget build(BuildContext context) {
var bloc = BlocProvider.of<MyForm>(context);
return Scaffold(
body: Center(
child: RaisedButton(
onPressed: () {
bloc.add(ThirdPageSubmitEvent(
inputE: 'text5',
inputF: 'text6',
));
Navigator.pushAndRemoveUntil(
context,
MaterialPageRoute(builder: (context) => HomePage()),
(r) => r == null,
);
},
child: Text('page 3'),
),
),
);
}
}
class MyForm extends Bloc<MyFormEvent, MyFromState> {
MyForm() : super(MyFromState.empty);
@override
Stream<MyFromState> mapEventToState(MyFormEvent event) async* {
if (event is FirstPageSubmitEvent) {
yield (state.copyWith(
inputA: event.inputA,
inputB: event.inputB,
));
} else if (event is SecondPageSubmitEvent) {
yield (state.copyWith(
inputC: event.inputC,
inputD: event.inputD,
));
} else if (event is ThirdPageSubmitEvent) {
yield (state.copyWith(
inputE: event.inputE,
inputF: event.inputF,
));
}
}
}
abstract class MyFormEvent extends Equatable {}
class FirstPageSubmitEvent extends MyFormEvent {
FirstPageSubmitEvent({this.inputA, this.inputB});
final String inputA;
final String inputB;
@override
List<Object> get props => [inputA, inputB];
}
class SecondPageSubmitEvent extends MyFormEvent {
SecondPageSubmitEvent({this.inputC, this.inputD});
final String inputC;
final String inputD;
@override
List<Object> get props => [inputC, inputD];
}
class ThirdPageSubmitEvent extends MyFormEvent {
ThirdPageSubmitEvent({this.inputE, this.inputF});
final String inputE;
final String inputF;
@override
List<Object> get props => [inputE, inputF];
}
class MyFromState extends Equatable {
final String inputA;
final String inputB;
final String inputC;
final String inputD;
final String inputE;
final String inputF;
const MyFromState({
this.inputA,
this.inputB,
this.inputC,
this.inputD,
this.inputE,
this.inputF,
});
static const empty = MyFromState(
inputA: '',
inputB: '',
inputC: '',
inputD: '',
inputE: '',
inputF: '',
);
MyFromState copyWith({
String inputA,
String inputB,
String inputC,
String inputD,
String inputE,
String inputF,
}) {
return MyFromState(
inputA: inputA ?? this.inputA,
inputB: inputB ?? this.inputB,
inputC: inputC ?? this.inputC,
inputD: inputD ?? this.inputD,
inputE: inputE ?? this.inputE,
inputF: inputF ?? this.inputF,
);
}
@override
List<Object> get props => [inputA, inputB, inputC, inputD, inputE, inputF];
}
import'包:equalable/equalable.dart';
进口“包装:颤振/材料.省道”;
进口“包装:颤振团/颤振团.飞镖”;
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BlocProvider(
创建:()=>MyForm(),
孩子:MaterialApp(
标题:“颤振演示”,
主页:主页(),
),
);
}
}
类主页扩展了无状态小部件{
小部件构建(构建上下文){
返回脚手架(
正文:专栏(
mainAxisAlignment:mainAxisAlignment.center,
crossAxisAlignment:crossAxisAlignment.stretch,
儿童:[
BlocBuilder(
建筑商:(u,州){
返回列(
mainAxisAlignment:mainAxisAlignment.center,
crossAxisAlignment:crossAxisAlignment.center,
儿童:[
Text('inputA:${state.inputA}'),
Text('inputB:${state.inputB}'),
Text('inputC:${state.inputC}'),
Text('inputD:${state.inputD}'),
Text('inputE:${state.inputE}'),
Text('inputF:${state.inputF}'),
],
);
},
),
居中(
孩子:升起按钮(
已按下:(){
导航器。推(
上下文
MaterialPage路由(生成器:(上下文)=>FirstPage()),
);
},
子项:文本('start'),
),
),
],
),
);
}
}
类FirstPage扩展了无状态小部件{
小部件构建(构建上下文){
var bloc=BlocProvider.of(上下文);
返回脚手架(
正文:中(
孩子:升起按钮(
已按下:(){
bloc.add(第一页提交事件)(
输入:“text1”,
inputB:'text2',
));
导航器。推(
上下文
MaterialPage路由(生成器:(上下文)=>SecondPage()),
);
},
子项:文本(“第2页”),
),
),
);
}
}
类SecondPage扩展了无状态小部件{
小部件构建(构建上下文){
var bloc=BlocProvider.of(上下文);
返回脚手架(
正文:中(
孩子:升起按钮(
已按下:(){
集团添加(第二页提交事件)(
inputC:'text3',
输入:“text4”,
));
导航器。推(
上下文
MaterialPageRoute(生成器:(上下文)=>ThirdPage()),
);
},
子项:文本(“第3页”),
),
),
);
}
}
类ThirdPage扩展了无状态小部件{
小部件构建(构建上下文){
var bloc=BlocProvider.of(上下文);
返回脚手架(
正文:中(
孩子:升起按钮(
已按下:(){
集团添加(第三页提交事件)(
输入:“text5”,
inputF:'text6',
));
Navigator.pushandremove直到(
上下文
MaterialPackageRoute(生成器:(上下文)=>HomePage()),
(r) =>r==null,
);
},
子项:文本(“第3页”),
),
),
);
}
}
类MyForm扩展了Bloc{
MyForm():super(MyFromState.empty);
@凌驾
流mapEventToState(MyFormEvent事件)异步*{
如果(事件为FirstPageSubmitEvent){
收益率(state.copyWith)(
输入:event.inputA,
inputB:event.inputB,
));
}else if(事件为SecondPageSubmitEvent){
收益率(state.copyWith)(
inputC:event.inputC,
inputD:event.inputD,
));
}else if(事件为第三页提交事件){
收益率(state.copyWith)(
输入:event.input,
inputF:event.inputF,
));
}
}
}
抽象类MyFormEvent扩展了可等式{}
类FirstPageSubmitEvent扩展MyFormEvent{
FirstPageSubmitEvent({this.inputA,this.inputB});
最终字符串输入;
最终字符串输入b;
@凌驾
列表获取道具=>[inputA,inputB];
}
类SecondPageSubmitEvent扩展MyFormEvent{
SecondPageSubmitEvent({this.inputUTC,this.inputD});
最终字符串输入UTC;
最终字符串输入;
@凌驾
列表获取道具=>[inputC