尝试通过调用父小部件中的函数来显示警报对话框。I/flutter ( 4041): MyApp widgets require MaterialLocalizations to be provided by a Localizations widgetapplication to I/flutter ( 4041): include them automatically, or add a Localization widget with a MaterialLocalizations
extends StatelessWidget { Widget build(BuildContext context) {Error: A non-null value must be returned since the return type 'Widget' doesn't allow null.- 'Widget' is from 'package:flutter/src&
snapshot) {
}, }
唯一的问题是,显然构建器函数在构建主体小部件时异步运行I/flutter (28504): This _DefaultInheritedProviderScope<FAAuthModel> widget cannot be marked as needingA widget can be marked as nee
函数在MaterialApp home属性运行引导时处理此路由机制。I/flutter ( 4502): This Overlay widget cannot be marked as needing to build because the framework isA widget can be marked as needing to be built during the build phase
I/flutter ( 4502): only if one ofI/<e
我是颤振编程的初学者,我试过一个例子,它会抛出错误,比如一个构建函数返回了null.Is,我的代码有什么问题吗?I/flutter ( 1781): RandomWords
I/flutter ( 1781): BuildI/flutter ( 1781): To return an empty space that causes the b