eee

CollectionView多选

导航字体颜色：[self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName: [UIColor whiteColor],

                                                                      NSForegroundColorAttributeName : [UIFont boldSystemFontOfSize:18]}];

https://www.jianshu.com/p/c5f4e784848c 安装rvm

command line tool

OpenSSL

rvm

ruby

gem

cocoapods

https://blog.csdn.net/andy_jiangbin/article/details/79159716 头疼