1.'flutter_boost' file not found
導入flutter_boost框架時，要在flutter的開發工具(Android Studio)上執行 build->flutter->iOS 打包，flutter工程文件夾下的build/ios/Release-iphoneos就會生成flutter_boost，然後再去iOS工程中執行pod install。
2.The plugin `flutter_boost` is built using an older version of the Android plugin API which assumes that it's running in a full-Flutter environment. It may have undefined behaviors when Flutter is integrated into an existing app as a module.
暫時不處理，可以參考官方文檔
3.NoMethodError - undefined method `size' for nil:NilClass
使用Android Studio 先執行Pub upgrade, 然後Tools->Flutter->Flutter clean. 再重新 build ->flutter->build iOS。