for 循环仅返回 ListView.builder 内的 List 的第一个元素，但它适用于构建小部件

Question

我有一个在 Build 下的列表，它适用于 ListView.builder 之外，但 ListView.builder 内部的循环只会返回第一个元素，为什么？ 感谢您的建议！

  Widget build(BuildContext context) {
    List eventList = [
      TimelineModel(              
          eventTitle: 'first',),
      TimelineModel(              
          eventTitle: 'second'),
    ];    
    return GetBuilder<TimelineController>(builder: (controller) {
          for(var e in eventList){
            print('???${e.eventTitle}'); // here loops work
          }
          return Scaffold(          
            body: Container(              
              child: Stack(
                children: [                
                  ListView.builder(            
                    itemBuilder: (context, index) {
                      for (var event in eventList) 
                          print('------${event.eventTitle}------'); // here loop will only return first element                       
                  ),                  
                ],
              ),
            ),
          );
        }
    );

Answer 1

您可能想像这样使用它：

ListView.builder(
    itemCount: eventList.length,
    itemBuilder: (context, index) {
      print('------${eventList[index].eventTitle}------');
      return Text(eventList[index].eventTitle);
    }
),

Answer 2

在ListView.builder()中添加itemCount

Widget build(BuildContext context) {
    List eventList = [
      TimelineModel(              
          eventTitle: 'first',),
      TimelineModel(              
          eventTitle: 'second'),
    ];    
    return GetBuilder<TimelineController>(builder: (controller) {
          for(var e in eventList){
            print('???${e.eventTitle}'); // here loops work
          }
          return Scaffold(          
            body: Container(              
              child: Stack(
                children: [                
                  ListView.builder( 
                    itemCount: eventList.length,            
                    itemBuilder: (context, index) {
                      for (var event in eventList) 
                          print('------${event.eventTitle}------'); // here loop will only return first element                       
                  ),                  
                ],
              ),
            ),
          );
        }
    );

Answer 3

试试下面的代码：

ListView.builder(
  itemCount: eventList.length,
  itemBuilder: (context, index) {
    final event = eventList[index];

    print('------${event.eventTitle}------');
    return Text(event.eventTitle);
  },
),