問題: Scaffold.of() called with a context that does not contain a Scaffold. No Scaffold ancestor could be found starting from the context that was passed to Scaffold.of(). This usually happens when the context provided is from the same StatefulWidget as that whose build function actually creates the Scaffold widget being sought. There are several ways to avoid this problem. The simplest is to use a Builder to get a context that is 「under」 the Scaffold. For an example of this, please see the documentation for Scaffold.of(): . 解決辦法: 方法一： 將報錯的widget從原來的類移出來,從新寫一個StatelessWidget或者StatefulWidget的類,其中build函數將原widget放入Scaffold中來寫。若是進一步有報錯講h<infinity,即高度無限,將Scaffold放入一個有高度限制的Container便可。 方法二： 使用GlobalKey,下面以SnackBar做爲例子git
class _MyHomePageState extends State<MyHomePage> {
final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();
@override
Widget build(BuildContext context) {
return Scaffold(
key: _scaffoldKey,
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_scaffoldKey.currentState.showSnackBar(
SnackBar(
content: Text('Assign a GlobalKey to the Scaffold'),
duration: Duration(seconds: 3),
));
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問題
報錯：github
FAILURE: Build failed with an exception.
* What went wrong:
> no meothd jcenter found for root build.gradle
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
BUILD FAILED
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