变量的set get方法
必须保持一致的类型
Execution failed for task ':app:mergeDebugJavaResource'.
A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade File 'com.android.builder.files.ZipCentralDirectory@69765e30' was deleted, but previous version not found in cache
flutter channel stable
flutter upgrade --force
flutter pub cache repair
cd <YOUR APP FOLDER>
flutter clean
入口不是MaterialApp或CupertinoApp
会影响需要顶级是上述对象的组件，目前已知的有TextFiled，SafeArea
