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Flutter 是否允许在底部板材颤振中创建多个下拉菜单?我犯了一个错误_Flutter_Dart_Flutter Layout_Flutter Widget - Fatal编程技术网

Flutter 是否允许在底部板材颤振中创建多个下拉菜单?我犯了一个错误

Flutter 是否允许在底部板材颤振中创建多个下拉菜单?我犯了一个错误,flutter,dart,flutter-layout,flutter-widget,Flutter,Dart,Flutter Layout,Flutter Widget,这是我的字符串列表: final List<String> cupsize = ['Select', 'Small', 'Medium', 'Large']; final List<String> flavour = [ 'Chocolate', 'Vanilla', 'Strawberry', 'Blueberry', 'Raspberry', 'Kiwi' 'Select' ]; String

这是我的字符串列表:

final List<String> cupsize = ['Select', 'Small', 'Medium', 'Large'];

  final List<String> flavour = [
    'Chocolate',
    'Vanilla',
    'Strawberry',
    'Blueberry',
    'Raspberry',
    'Kiwi'
        'Select'
  ];

String _currentCupSize;
String _currentFlavour;

cupsize代码工作正常,但一旦编写了flavor函数, 它说:

我参考了一些其他的答案,但没有一个能解决我的问题

任何帮助都将不胜感激:)

我在这里看到两个问题

一是你在
列表
中的
'Kiwi'
之后遗漏了一个

第二,在
flavor
列表中有
'Select'
。但是,第二个
下拉按钮表单字段的默认值是
'One'
。 因此,或者将默认值更改为
'Select'
,或者将列表中的最后一个值更改为
'One'

final List<String> flavour = [
  'Chocolate',
  'Vanilla',
  'Strawberry',
  'Blueberry',
  'Raspberry',
  'Kiwi',
  'One'
];
最终列表味道=[
“巧克力”,
“香草”,
“草莓”,
“蓝莓”,
“覆盆子”,
“猕猴桃”,
“一个”
];
因为它没有在列表中看到您的
'One'
默认值,所以它抛出了错误

final List<String> flavour = [
  'Chocolate',
  'Vanilla',
  'Strawberry',
  'Blueberry',
  'Raspberry',
  'Kiwi',
  'One'
];