问题描述：
root@zhouls-virtual-machine:~# apt-get install vim
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package vim is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'vim' has no installation candidate
root@zhouls-virtual-machine:~#
解决办法：
sudo apt-get update && sudo apt-get install vim
成功！