import 'package:flutter/material.dart'; class Home2 extends StatefulWidget { const Home2({Key? key}) : super(key: key); @override State<Home2> createState() => _State(); } class _State extends State<Home2> { @override Widget build(BuildContext context) { print("built method Home2")...
The method ‘setState’ isn’t defined for the type XXX setState简介 在Flutter中,通常使用StatefulWidget和State对象来管理小部件的状态。StatefulWidget是一个可变的小部件,可以根据需要重新构建,而State对象是一个不可变的对象,它包含小部件的状态和逻辑。当小部件需要更新其状态时,它会调用setState方法,以通知Fl...
SystemChannels.navigation.setMethodCallHandler(_handleNavigationInvocation); SystemChannels.system.setMessageHandler(_handleSystemMessage); FlutterErrorDetails.propertiesTransformers.add(transformDebugCreator); } } 我们可以看到buildOwner.onBuildScheduled回调等于了_handleBuildScheduled,那现在来看看这个_handleBuildSchedu...
SystemChannels.navigation.setMethodCallHandler(_handleNavigationInvocation); SystemChannels.system.setMessageHandler(_handleSystemMessage); FlutterErrorDetails.propertiesTransformers.add(transformDebugCreator); } } 可以看到Flutter应用启动过程初始化WidgetsBinding时buildOwner.onBuildScheduled回调等于了_handleBuildScheduled...
SystemChannels.navigation.setMethodCallHandler(_handleNavigationInvocation); SystemChannels.system.setMessageHandler(_handleSystemMessage); FlutterErrorDetails.propertiesTransformers.add(transformDebugCreator); } } 1. 2. 3. 4. 5. 6. 7. 8. 9. ...
// 赋值onBuildScheduledwindow.onLocaleChanged=handleLocaleChanged;window.onAccessibilityFeaturesChanged=handleAccessibilityFeaturesChanged;SystemChannels.navigation.setMethodCallHandler(_handleNavigationInvocation);SystemChannels.system.setMessageHandler(_handleSystemMessage);FlutterErrorDetails.propertiesTransformers.add(...
error in flutter is caused by a problem with the import, usage, or context of the setstate method. by importing the ‘flutter’ package, checking that the widget is stateful, checking the context, checking the variable name, checking for missing dependencies, and cleaning and rebuilding the ...
SystemChannels.navigation.setMethodCallHandler(_handleNavigationInvocation); SystemChannels.system.setMessageHandler(_handleSystemMessage); }void_handleBuildScheduled(){ ensureVisualUpdate();//[见小节2.5]} } 在Flutter应用启动过程初始化WidgetsBinding时,赋值onBuildScheduled等于_handleBuildScheduled()。
Error:Method not found:'setState'.onPressed:(){setState((){_timer-=1.0;});^^^FAILURE:Build failedwithan exception.*Where:Script'C:\flutter\packages\flutter_tools\gradle\flutter.gradle'line:1159*What went wrong:Execution failedfortask':app:compileFlutterBuildDebug'.>Process'command 'C:\flutter...
setState未更新Flutter中的UI 这是一个非常粗略的工作示例,但您可以在此基础上继续。在下面的代码中,您可以看到我创建了两个方法,用于为每个小部件设置复选框的状态。一旦触发此方法,我也会重置页面。这会触发内部小部件的重画(这是我在评论中解释的)。 class _DemoDialogState extends State<DemoDialog> { Widge...