国内下载Flutter

出现镜像错误等现象属于源码包不全面，国内下载镜像添加环境变量。

①：Linux执行如下操作

export PUB_HOSTED_URL=https://pub.flutter-io.cn
export FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn
git clone -b dev https://github.com/flutter/flutter.git
export PATH="$PWD/flutter/bin:$PATH"
cd ./flutter
flutter doctor

②：Windows执行如下操作

添加环境变量

PUB_HOSTED_URL https://pub.flutter-io.cn
FLUTTER_STORAGE_BASE_URL https://storage.flutter-io.cn

在原来不完整的包下执行flutter doctor