[英]flutter loop inside a widget
I'm new to flutter and was wondering if anyone would be able to guide me. 我是新来的人,想知道是否有人能指导我。
I would like to irritate through a string that I retrieved from a json file. 我想通过从json文件中检索到的字符串来激怒。 I would like to display each letter separately. 我想分别显示每个字母。 Example below. 以下示例。
Output Complete Word: Hi Letter pos 0: H Letter pos 1: I 输出完整单词:嗨信pos 0:H Letter pos 1:I
What I tried so far is adding a for loop below the itemBuilder but can't retrieve the variable inside the card. 到目前为止我尝试的是在itemBuilder下面添加一个for循环但是无法检索卡内的变量。 I tried adding a for loop inside the Widget and it doesn't allow me. 我尝试在Widget中添加一个for循环,它不允许我。
Any input would be greatly appreciated! 任何投入将不胜感激!
import 'dart:convert';
import 'package:flutter/material.dart';
void main() {
runApp(new MaterialApp(
home: new MyApp(),
));
}
class MyApp extends StatefulWidget {
@override
MyAppState createState() => new MyAppState();
}
class MyAppState extends State<MyApp> {
List data;
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text("Load local JSON file"),
),
body: new Container(
child: new Center(
// Use future builder and DefaultAssetBundle to load the local JSON file
child: new FutureBuilder(
future: DefaultAssetBundle
.of(context)
.loadString('data_repo/starwars_data.json'),
builder: (context, snapshot) {
// Decode the JSON
var new_data = JSON.decode(snapshot.data.toString());
return new ListView.builder(
// Build the ListView
itemBuilder: (BuildContext context, int index) {
return new Card(
child: new Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
new Text("Complete Word: " + new_data[index]['complete_word'])
],
),
);
},
itemCount: new_data == null ? 0 : new_data.length,
);
}),
),
));
}
}
Create a method and within it create a list of widgets. 创建一个方法,并在其中创建一个小部件列表。 Include the widgets and then return the list. 包括小部件,然后返回列表。
Example 例
child: new Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: ListMyWidgets()),
List<Widget> ListMyWidgets() {
List<Widget> list = new List();
list.add(new Text("hi"));
list.add(new Text("hi2"));
list.add(new Text("hi3"));
return list;
}
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