在颤动中将List<List<dynamic>>转换为ArrayList

Question

我是flutter的新手，我想将列表转换为ArrayList。下面是我当前的列表输出

数据[数量，描述，单价，总价[1, Jeans, 106.0, 106.0], [2, Shirt, 24.38, 24.38], [3, Demo Hoodie / XL, 106.0, 318.0], [4, Demo Hoodie / 2XL, 106.0, 106.0], [1, 牛仔裤-短款, 106.0, 106.0], [5, 衬衫-长款, 24.38, 24.38], [6, Demo Hoodie-Lg / XL, 106.0, 318.0], [ Demo Hoodie-Mg / 2XL, 106.0, 106.0], [3, Jeans-RG, 106.0, 106.0], [4, Shirt-MG, 24.38, 24.38], [7, Demo Hoodie-TY / XL, 106.0, 318.0] , [9, Demo Hoodie-Levis / 2XL, 106.0, 106.0], [1, Demo Hoodie-J&J / XL, 106.0, 318.0], [2, Demo Hoodie-M&J / 2XL, 106.0, 107, Temo], [ Hoodie-TY / XL, 106.0, 318.0], [5, Zemo Hoodie-Levis / 2XL, 106.0, 106.0], [6, Aemo Hoodie-J&J / XL, 106.0, 318.0], [2, Bemo Hoodie/J2XLM , 106.0, 106.0], [9, Temo Hoodie-TY / XL, 106.0, 318.0], [1, Zemo Hoodie-Levis / 2XL, 106.0, 106.0], [2, Aemo Hoodie-J&J / XL, 136.0.]10 , [7, Bemo Hoodie-M&J / 2XL, 106.0, 106.0]]

我想将该数组列表添加到flutter中的recyclerView中。

提前谢谢。

Answer 1

您可以使用dart:convert并使用jsonDecode但是这是不会起作用的，除非你从这个添加单引号/双引号到每个单词的字符串中删除。

或者，您可以通过拆分字符串来手动转换它。

import 'dart:core';

main(){
  
 String data = "[[Qty, Desc, Unitprice, totalprice], [1, Jeans, 106.0, 106.0], [2, Shirt, 24.38, 24.38], [3, Demo Hoodie / XL, 106.0, 318.0], [4, Demo Hoodie / 2XL, 106.0, 106.0], [1, Jeans-short, 106.0, 106.0], [5, Shirt-Long, 24.38, 24.38], [6, Demo Hoodie-Lg / XL, 106.0, 318.0], [4, Demo Hoodie-Mg / 2XL, 106.0, 106.0], [3, Jeans-RG, 106.0, 106.0], [4, Shirt-MG, 24.38, 24.38], [7, Demo Hoodie-TY / XL, 106.0, 318.0], [9, Demo Hoodie-Levis / 2XL, 106.0, 106.0], [1, Demo Hoodie-J&J / XL, 106.0, 318.0], [2, Demo Hoodie-M&J / 2XL, 106.0, 106.0], [7, Temo Hoodie-TY / XL, 106.0, 318.0], [5, Zemo Hoodie-Levis / 2XL, 106.0, 106.0], [6, Aemo Hoodie-J&J / XL, 106.0, 318.0], [2, Bemo Hoodie-M&J / 2XL, 106.0, 106.0], [9, Temo Hoodie-TY / XL, 106.0, 318.0], [1, Zemo Hoodie-Levis / 2XL, 106.0, 106.0], [2, Aemo Hoodie-J&J / XL, 106.0, 318.0], [7, Bemo Hoodie-M&J / 2XL, 106.0, 106.0]]";
  
  
  List splittedData = data.substring(2,data.length-1).split("], [");


  List> formattedData = [];

  splittedData.forEach( (stringVal) => formattedData.add(stringVal.split(', ')));

  print(formattedData[0][0]);
  

}

您可以运行以下代码dartpad.dev检查其输出。

通过使用正则表达式来解析数据，而不是使用字符串拆分数据，可以进一步改进这一点。如果数据本身不一致，并且其中有单引号/双引号和方括号，就会出现这种情况。

Answer 2

• 对于这种用法，应该使用对象，如List而不是List
• Flutter中没有RecyclerView，它是ListView小部件。
• 字符串应在引号("")之间

下面是一个使用ListView构建器的示例：

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      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 {
  
  var list = [["data1", "data2"], ["data1","data2"],["data1","data2"]];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: ListView.builder(
          itemCount: list.length,
          itemBuilder: (context, index) {
            return Container(
              color: Colors.grey[200],
              padding: EdgeInsets.symmetric(vertical: 10),
              child: Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: List.generate(
                  list[index].length,
                  (index2) {
                    return Text(list[index][index2]);
                  }
                )
              ),
            );
          }
        )
      ),
    );
  }
}