flutter循环

flutter for循环：

Wrap(
     children: <Widget>[
         for (int i = 0; i < (xx.yy.data?.items?.length ?? 0); i++)
            TextButton(onPressed: (){}, child: Text("${xx.yy.data?.items?[i].name.toString()} (${xx.yy.data?.items?[i].connId.toString()}) "))
    ],
);

另一种方法：

import 'package:flutter/material.dart';
import './fonts.dart';
import 'package:flutter_basic/res/listData.dart';

void main() {
  runApp(MaterialApp(
    home: Scaffold(
      appBar: AppBar(
        title: const Text('hello flutter'),
      ),
      body: const Myapp(),
    ),
  ));
}

class Myapp extends StatelessWidget {
  const Myapp({Key? key}) : super(key: key);
  
  /// 定义组件
  /// 第一种方法：for循环
  // List<Widget> _initListData() {
  //   List<Widget> tempList = [];
  //   for (var i = 0; i < listData.length; i++) {
  //     tempList.add(ListTile(
  //       leading: Image.network("${listData[i]["imageUrl"]}"),
  //       title: Text("${listData[i]["title"]}"),
  //       subtitle: Text("${listData[i]["author"]}"),
  //     ));
  //   }
  //   return tempList;
  // }


  ///第二种方法：map
  List<Widget> _initListData() {
    var tempList = listData.map((e) {
      return ListTile(
        leading: Image.network("${e["imageUrl"]}"),
        title: Text("${e["title"]}"),
        subtitle: Text("${e["author"]}"),
      );
    });
    return tempList.toList();
  }

  @override
  Widget build(BuildContext context) {
    print(listData);
    return ListView(
      children: _initListData(),///使用
    );
  }
}

使用ListView提供的builder构造函数来生成一个动态列表，在builder里需要传人两个必传参数itemCount、itemBuilder

class Myapp extends StatelessWidget {
  const Myapp({Key? key}) : super(key: key);

  ///使用ListView提供的builder构造函数来生成一个动态列表
  /// 在builder里需要传人两个必传参数itemCount、itemBuilder

  @override
  Widget build(BuildContext context) {
    return ListView.builder(
        itemCount: listData.length,
        itemBuilder: (context, index) {
          return ListTile(
           leading: Image.network("${listData[index]["imageUrl"]}"),
            title: Text("${listData[index]["title"]}"),
            subtitle: Text("${listData[index]["author"]}"),
          );
        });
  }
}