类似新浪微博的下拉菜单
https://github.com/PhamBaTho/BTNavigationDropdownMenu
导入文件夹KTDropdownMenuView到工程中
NSArray *titles = @[@"首页", @"朋友圈", @"我的关注", @"明星", @"家人朋友"];
KTDropdownMenuView *menuView = [[KTDropdownMenuView alloc] initWithFrame:CGRectMake(0, 0,100, 44) titles:titles];
self.navigationItem.titleView = menuView;
block进行回调
menuView.selectedAtIndex = ^(int index)
{
NSLog(@"selected title:%@", titles[index]);
};