flutter ios 无法运行，获取小部件库异常和设备连接丢失

Posted 2023-02-23

【中文标题】flutter ios 无法运行，获取小部件库异常和设备连接丢失

【英文标题】：flutter ios can't run, getting widgets library exceptions and lost device connetion

【发布时间】：2020-05-12 11:58:07

【问题描述】：

我在运行应用程序时收到以下错误问题的可能原因是什么？

Launching lib/main.dart on iPhone 8 Plus in debug mode...
Xcode build done.                                           48.9s
flutter: ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
flutter: The following assertion was thrown building TextField(controller:
flutter: TextEditingController#a4d28(TextEditingValue(text: ┤├, selection: TextSelection(baseOffset: -1,
flutter: extentOffset: -1, affinity: TextAffinity.downstream, isDirectional: false), composing:
flutter: TextRange(start: -1, end: -1))), enabled: false, decoration: InputDecoration(labelText: "Receiving
flutter: UPI Address", hintText: "address@upi", border: OutlineInputBorder(), alignLabelWithHint: false),
flutter: dirty, state: _TextFieldState#cc557):
flutter: No Material widget found.
flutter: TextField widgets require a Material widget ancestor.
flutter: In material design, most widgets are conceptually "printed" on a sheet of material. In Flutter's
flutter: material library, that material is represented by the Material widget. It is the Material widget
flutter: that renders ink splashes, for instance. Because of this, many material library widgets require that
flutter: there be a Material widget in the tree above them.
flutter: To introduce a Material widget, you can either directly include one, or use a widget that contains
flutter: Material itself, such as a Card, Dialog, Drawer, or Scaffold.
flutter: The specific widget that could not find a Material ancestor was:
flutter:   TextField

也试过了：

颤振医生-v

颤抖干净

【参考方案1】：

错误为No Material widget found，因此TextField 小部件必须是MaterialApp 的子级。喜欢关注

class CustomWidget extends StatelessWidget 
  @override
  Widget build(BuildContext context) 
    return MaterialApp(
      home: Scaffold(
        body: TextField(
          // ... named parameters for this widget
        ),
      ),
    );

【讨论】：

您能否发布基本小部件，您如何将其实现为演示代码，删除所有其他内容，如动画、动画控制器等。如果我不知道您的小部件层次结构并且不会是，颤振是嵌套小部件能够为您的案例提供正确的解决方案。从我上面回答的错误中。看看我提出的问题并为它写了一个演示：How to know pop event happened inside Nested Widget in Flutter