// 更新flutter
flutter upgrade  

// Dart 构造函数默认值
ImageGridView({Key key, this.imgs, this.isEdit: false})

// flutter 更新包时卡死,命令行展示如下
Waiting for another flutter command to release the startup lock...
// 控制台执行以下命令
rm ./flutter/bin/cache/lockfile

// Flutter bloc使用 推荐
https://pub.dev/packages/flutter_bloc