Listview 如何通过此代码中的按钮在HistoryListTile中添加项目?颤振
Listview 如何通过此代码中的按钮在HistoryListTile中添加项目?颤振,listview,flutter,dart,flutter-layout,Listview,Flutter,Dart,Flutter Layout,ListView( 收缩膜:对, 滚动方向:轴垂直, 儿童:[ 组织分裂( iconColor:IconColors.transfer, onTap:(){}, TransactionMount:“+\$210.00”, transactionIcon:IconImgs.transfer, 交易名称:“Amazigh Halzoun”, transactionType:“转账”, ), ], ), class HistoryListTile extends StatelessWidget {
ListView(
收缩膜:对,
滚动方向:轴垂直,
儿童:[
组织分裂(
iconColor:IconColors.transfer,
onTap:(){},
TransactionMount:“+\$210.00”,
transactionIcon:IconImgs.transfer,
交易名称:“Amazigh Halzoun”,
transactionType:“转账”,
),
],
),
class HistoryListTile extends StatelessWidget {
final Color iconColor;
final String transactionName,
transactionType,
transactionAmount,
transactionIcon;
final GestureTapCallback onTap;
const HistoryListTile({
Key key,
this.iconColor,
this.transactionName,
this.transactionType,
this.transactionAmount,
this.transactionIcon,
this.onTap,
}) : super(key: key);
@override
Widget build(BuildContext context) {
return Material(
color: Colors.transparent,
child: ListTile(
title: Text(transactionName),
subtitle: Text(transactionType),
trailing: Text(transactionAmount),
leading: CircleAvatar(
radius: 25,
child: Image.asset(
transactionIcon,
height: 25,
width: 25,
),
backgroundColor: iconColor,
),
enabled: true,
onTap: onTap,
),
);
}
}
很快我们就有了一个名为HistoryListTile的Dart文件,它定义了列表的参数和设计
您可以复制粘贴运行下面的完整代码
使用
课程历史记录
和列表
控制将数据添加到
列表
时,使用setState,它将显示在ListView中代码片段
List<History> historyList = [];
...
setState(() {
historyList.add(History(iconColor: Colors.blue, transactionAmount: "100", transactionIcon: "abc", transactionName: "Hi",transactionType: "def"));
...
class History {
Color iconColor;
String transactionName;
String transactionType;
String transactionAmount;
String transactionIcon;
History({
this.iconColor,
this.transactionName,
this.transactionType,
this.transactionAmount,
this.transactionIcon,
});
List historyList=[];
...
设置状态(){
添加(历史记录(iconColor:Colors.blue,TransactionMount:“100”,transactionIcon:“abc”,transactionName:“Hi”,transactionType:“def”);
...
课堂历史{
彩色iconColor;
字符串transactionName;
字符串事务类型;
字符串事务装载;
字符串事务图标;
历史({
这个.iconColor,
这个.transactionName,
这个.transactionType,
这个,这个,,
此.transactionIcon,
});
工作演示
完整代码
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
final List<String> entries = <String>['A', 'B', 'C'];
final List<int> colorCodes = <int>[600, 500, 100];
List<History> historyList = [];
void _incrementCounter() {
setState(() {
historyList.add(History(iconColor: Colors.blue, transactionAmount: "100", transactionIcon: "abc", transactionName: "Hi",transactionType: "def"));
// This call to setState tells the Flutter framework that something has
// changed in this State, which causes it to rerun the build method below
// so that the display can reflect the updated values. If we changed
// _counter without calling setState(), then the build method would not be
// called again, and so nothing would appear to happen.
_counter++;
});
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: ListView.builder(
padding: const EdgeInsets.all(8),
itemCount: historyList.length,
itemBuilder: (BuildContext context, int index) {
return HistoryListTile(
iconColor: historyList[index].iconColor,
onTap: () {},
transactionAmount: historyList[index].transactionAmount,
transactionIcon: historyList[index].transactionIcon,
transactionName: historyList[index].transactionName,
transactionType: historyList[index].transactionType,
);
}
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
class History {
Color iconColor;
String transactionName;
String transactionType;
String transactionAmount;
String transactionIcon;
History({
this.iconColor,
this.transactionName,
this.transactionType,
this.transactionAmount,
this.transactionIcon,
});
factory History.fromJson(Map<String, dynamic> json) => History(
iconColor: json["iconColor"],
transactionName: json["transactionName"],
transactionType: json["transactionType"],
transactionAmount: json["transactionAmount"],
transactionIcon: json["ransactionIcon"],
);
Map<String, dynamic> toJson() => {
"iconColor": iconColor,
"transactionName": transactionName,
"transactionType": transactionType,
"transactionAmount": transactionAmount,
"ransactionIcon": transactionIcon,
};
}
class HistoryListTile extends StatelessWidget {
final Color iconColor;
final String transactionName,
transactionType,
transactionAmount,
transactionIcon;
final GestureTapCallback onTap;
const HistoryListTile({
Key key,
this.iconColor,
this.transactionName,
this.transactionType,
this.transactionAmount,
this.transactionIcon,
this.onTap,
}) : super(key: key);
@override
Widget build(BuildContext context) {
return Material(
color: Colors.transparent,
child: ListTile(
title: Text(transactionName),
subtitle: Text(transactionType),
trailing: Text(transactionAmount),
leading: CircleAvatar(
radius: 25,
child: Image.asset(
transactionIcon,
height: 25,
width: 25,
),
backgroundColor: iconColor,
),
enabled: true,
onTap: onTap,
),
);
}
}
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{
//此小部件是应用程序的根。
@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(
//这是应用程序的主题。
//
//尝试使用“flutter run”运行应用程序。您将看到
//应用程序有一个蓝色工具栏。然后,在不退出应用程序的情况下,重试
//将下面的primarySwatch更改为Colors.green,然后调用
//“热重新加载”(在运行“颤振运行”的控制台中按“r”,
//或者只需将更改保存到颤振IDE中的“热重新加载”。
//请注意,计数器没有重置回零;应用程序
//未重新启动。
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);
//此小部件是应用程序的主页。它是有状态的,表示
//它有一个状态对象(定义如下),其中包含影响
//看起来怎么样。
//此类是状态的配置。它保存值(在此
//案例名称)由家长(在本例中为应用程序小部件)提供,以及
//由State的build方法使用。小部件子类中的字段包括
//始终标记为“最终”。
最后的字符串标题;
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
int _计数器=0;
最终列表条目=['A','B','C'];
最终列表颜色代码=[600500100];
列表历史列表=[];
void _incrementCounter(){
设置状态(){
添加(历史记录(iconColor:Colors.blue,TransactionMount:“100”,transactionIcon:“abc”,transactionName:“Hi”,transactionType:“def”);
//这个对setState的调用告诉颤振框架,某些东西
//已在此状态下更改,这将导致它重新运行下面的生成方法
//以便显示能够反映更新的值。如果我们更改
//_计数器,而不调用setState(),则生成方法将不可用
//再打一次电话,似乎什么也没发生。
_计数器++;
});
}
@凌驾
小部件构建(构建上下文){
//每次调用setState时都会重新运行此方法,例如,按done
//通过上面的_incrementCounter方法。
//
//对颤振框架进行了优化,以制定重新运行的构建方法
//快速,这样你就可以重建任何需要更新的东西
//而不是必须单独更改小部件的实例。
返回脚手架(
appBar:appBar(
//在这里,我们从MyHomePage对象中获取由创建的值
//使用App.build方法,并使用它设置appbar标题。
标题:文本(widget.title),
),
正文:ListView.builder(
填充:常量边集。全部(8),
itemCount:historyList.length,
itemBuilder:(构建上下文,int索引){
返回历史列表(
iconColor:historyList[索引]。iconColor,
onTap:(){},
TransactionMount:historyList[索引]。TransactionMount,
transactionIcon:historyList[index]。transactionIcon,
transactionName:historyList[index]。transactionName,
transactionType:historyList[index]。transactionType,
);
}
),
浮动操作按钮:浮动操作按钮(
按下时:\ u递增计数器,
工具提示:“增量”,
子:图标(Icons.add),
),//此尾随逗号使生成方法的自动格式设置更方便。
);
}
}
课堂历史{
彩色iconColor;
字符串transactionName;
字符串事务类型;
字符串事务装载;
字符串事务图标;
历史({
这个.iconColor,
这个.transactionName,
这个.transactionType,
这个,这个,,
此.transactionIcon,
});
工厂历史。fromJson(映射json)=>历史(
iconColor:json[“iconColor”],
transactionName:json[“transactionName”],
transactionType:json[“transactionType”],
TransactionMount:json[“TransactionMount”],
transactionIcon:json[“transactionIcon”],
);
映射到JSON()=>{
“iconColor”:iconColor,
“交易Nam