在命令行中输入：export FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn
以使用国内镜像，如设置成功会出现：
Flutter assets will be downloaded from https://storage.flutter-io.cn. Make sure you trust this source!
- canvaskit download flutter Failed runcanvaskit download flutter failed download metadata failed adv-os download template registry failed 源码download办法failed flutter_download_manager flutter_download_manager download flutter manager download ignored instead failed assembledebug flutter running gradle download flutter version方法 canvaskit