This is fairly normal for an Xcode installation and normally when you exit iTunes the installation continues.
对于X code的安装来说，这是非常正常的，当你退出itunes之后，安装过程就会正常地继续下去。
2
Once the setup has completed, choose Finish to exit the installation panel.
完成设置后，选择Finish退出安装面板。
3
An exit program is typically used for any post-configuration required following the product installation, and can be used to determine if the installation of the solution is successful.