flutter 运行别人项目 包无法导入报错：Target of URI doesn't exist 'package:flutter/material.dart' 解决方法

命令行里运行 flutter packages get

iOS 接入 Flutter 报错：Invalid Podfile file: cannot load such file -- ../flutter_module/.ios/Flutter/podhelper.rb.

进入到当前项目flutterProject工程，执行 flutter clean
根据提示执行 flutter pub get
然后cd ios 到ios工程里面，
执行 Pod install即可

....flutterProject % flutter clean
....flutterProject % flutter pub get
....flutterProject % cd ios
....ios % pod install