CentOS7 Minimal下安装图形化界面的方法，有些时候纯命令界面确实比较累，个人学习可以使用图像界面，服务器强烈不建议用图形界面。
登录系统，使用yum 安装
yum -y groupinstall Desktop
yum -y groupinstall "X Window System"
安装GNOME桌面环境
yum install gnome-classic-session gnome-terminal nautilus-open-terminal control-center liberation-mono-fonts
#yum groupinstall 'X Window System' -y
如果安装KDE桌面环境
#yum groupinstall 'KDE (K Desktop Environment)' -y
如果发生错误：
Warning: Group GNOME Desktop Environment does not exist.
No packages in any requested group available to install or update
则可以先用yum grouplist 检查一下已安装的组可支持的组，获得对应的组名再安装
卸载GNOME桌面环境
#yum groupremove "GNOME Desktop Environment"
卸载KDE桌面环境
#yum groupremove "KDE (K Desktop Environment)"
登录系统，使用yum 安装
#yum groupinstall 'X Window System' -y
安装GNOME桌面环境
#yum groupinstall 'GNOME Desktop Environment' -y
如果安装KDE桌面环境
#yum groupinstall 'KDE (K Desktop Environment)' -y
如果发生错误：
Warning: Group GNOME Desktop Environment does not exist.
No packages in any requested group available to install or update
则可以先用yum grouplist 检查一下已安装的组可支持的组，获得对应的组名再安装
卸载GNOME桌面环境
#yum groupremove "GNOME Desktop Environment"
卸载KDE桌面环境
#yum groupremove "KDE (K Desktop Environment)"