// Override point for customization after application launch.
//初始化window, 大小为设备物理大小
self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
//把window的背景颜色改成白色
self.window?.backgroundColor = UIColor.whiteColor()
//让window作为主window显示
self.window?.makeKeyAndVisible()
/*-----------------初始化Tabbar控制器--------------*/
let home = UIViewController()
let message = UIViewController()
let search = UIViewController()
let setting = UIViewController()
let viewControllers = [home, message, search, setting]
let tabbarCtrl = UITabBarController()
tabbarCtrl.viewControllers = viewControllers
self.window?.rootViewController = tabbarCtrl
//创建UITabBarItem
//使用系统的样式创建
let tabItem1 = UITabBarItem(tabBarSystemItem: UITabBarSystemItem.Favorites, tag: 1)
home.tabBarItem = tabItem1
let tabItem2 = UITabBarItem(tabBarSystemItem: UITabBarSystemItem.Bookmarks, tag: 1)
message.tabBarItem = tabItem2
//使用自定义的图片、标题
let tabItem3 = UITabBarItem(title: "搜索", image: UIImage(named: "tabbar_discover_highlighted.png"), tag: 1)
search.tabBarItem = tabItem3
let tabItem4 = UITabBarItem(title: "设置", image: UIImage(named: "tabbar_profile_highlighted.png"), tag: 1)
setting.tabBarItem = tabItem4
/*------------------设置tabbar工具栏------------------*/
let tabbar = tabbarCtrl.tabBar
//设置tabBar的背景图片
var img = UIImage(named: "navbg.png")
UIGraphicsBeginImageContext(CGSizeMake(width, 49))
img?.drawInRect(CGRectMake(0, 0, width, 49))
img = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
tabbar.backgroundImage = img
//设置tabBar的选中图片颜色
tabbar.tintColor = UIColor.redColor()
//设置选中item后,盖在此item上的图片
tabbar.selectionIndicatorImage = UIImage(named: "选中.png")
//为item是指一个小图标
tabItem1.badgeValue = "New";