我试图在将数据存储到firebase数据库后获得新创建的文档id,但得到了错误。E/flutter (20333): [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: NoSuchMethodError: The method 'listen' was called on null.E/flutter (20333):
颤振:╞═══════════════════════════════════════════════════════════════════颤振手势捕捉到的══╡异常:在处理手势时抛出了以下NoSuchMethodError: flutter:方法‘called’在null上被调用。颤振:接收者:空颤振:尝试调用:验证() final
我有一个需求,我需要从sharedPreferences获取条件的代码,因此我做了下面的工作,这是有效的,但被认为是一个糟糕的做法,或者我应该说flutter正在推送警告。countryCode')}"; } }
通常,我会创建async函数并在initState()中调用它: NoSuchMethodError: The method 'get' was call
( 5186): [ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: NoSuchMethodError: The method'getQuestionFromFirebase' was called on null.E/flutter ( 5186): Receiver: null
E/flutter ( 5186):
我希望有一个好的一天,我正在努力在一个列中包装一个ListView.builder。: Another exception was thrown: NoSuchMethodError: The method '<=' was called on null.
flutter: Anotherwas thrown: NoSuchMethodError: The method '<=' was called on n