下载链接：https://www.mono-project.com/download/stable/#download-lin-debian
源码链接：https://github.com/mono/mono
Ubuntu 18.04 (i386, amd64, armhf, arm64, ppc64el)
sudo apt install gnupg ca-certificates sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF echo "deb https://download.mono-project.com/repo/ubuntu stable-bionic main" | sudo tee /etc/apt/sources.list.d/mono-official-stable.list sudo apt update
Ubuntu 16.04 (i386, amd64, armhf, arm64, ppc64el)
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF sudo apt install apt-transport-https ca-certificates echo "deb https://download.mono-project.com/repo/ubuntu stable-xenial main" | sudo tee /etc/apt/sources.list.d/mono-official-stable.list sudo apt update
安装开发环境：