1、在有网的情况下把离线包下载到电脑上
sudo yum install --downloadonly --downloaddir=/home/mjb/soft/dotnet-sdk-3.1 dotnet-sdk-3.1
sudo yum install --downloadonly --downloaddir=/home/mjb/soft/aspnetcore-runtime-3.1 aspnetcore-runtime-3.1
sudo yum install --downloadonly --downloaddir=/home/mjb/soft/dotnet-runtime-3.1 dotnet-runtime-3.1
2、然后把离线包拷贝到无网的电脑上,进行安装。首先切换到aspnetcore-runtime-3.1文件夹下，安装指令 rpm -ivh *.rpm
3、切换到dotnet-runtime-3.1文件夹下，安装指令 rpm -ivh *.rpm
4、切换到dotnet-sdk-3.1文件夹下，安装指令 rpm -ivh *.rpm
5、查看是否安装成功指令 dotnet --info
