飞镖列表中三个点(...)的用途是什么? [英] What's the usage of three dots (...) in dart List?

问题描述

我的代码是这样写的，但是它给出了一个错误:

I have my code written like this but it gives an error saying:

错误:不能将类型为列表"的值分配给类型为小部件"的变量.

Error: A value of type 'List' can't be assigned to a variable of type 'Widget'.

Column(
  children: [
    Question(
      questions[_questionIndex]['questionText'],
    ),
    ...(questions[_questionIndex]['answers'] as List<String>)
        .map((answer) {
      return Answer(_answerQuestion, answer);
    }).toList()
  ],
)

推荐答案

我知道了我的问题.我的Flutter SDK尚未升级.运行flutter doctor命令并整理出缺少的更新.而且语法现在似乎可以正常工作.

I've figured out my issue. My flutter SDK wasn't upgraded. Ran flutter doctor command and sorted out the missing updates. And the syntax seems to be working fine now.

flutter upgrade

Dart版本(必需)> = 2.3

Dart version (required) >= 2.3

重新启动IDE(如果问题仍然存在)

Restart IDE (if the problem persists)

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