搭建项目框架

1.创建一个根视图 (window)
2 根视图上添加根控制器 tabbarController
3.创建4个tableviewController (nav)添加到tabbarController的childController中

• 设置appdelegate

  func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    // Override point for customization after application launch.
    
    setupAppearance()
    
    window = UIWindow(frame: UIScreen.mainScreen().bounds)
    window?.backgroundColor = UIColor.orangeColor()
    window?.rootViewController = mainViewController()
  
    window?.makeKeyAndVisible()
    return true }
  

• 增加子控制器
  func addvc(title:String!,imageName:String!,selecterImage:String!)
  {
  var vc = UITableViewController()
  vc.title = title
  //修改默认渲染的颜色
  UITabBar.appearance().tintColor = UIColor.orangeColor()
  //修改图片默认渲染的颜色
  vc.tabBarItem.image = UIImage(named: imageName)?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal)
  vc.tabBarItem.selectedImage = UIImage(named: selecterImage)?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal)
  let nav = UINavigationController(rootViewController: vc)
  addChildViewController(nav)
  }

• 修改全局渲染
  private func setupAppearance(){
  UITabBar.appearance().tintColor = UIColor.orangeColor()
  UINavigationBar.appearance().tintColor = UIColor.orangeColor()
  }

• 增加发布按钮

  func addChildViewControllers() {
    addChildViewController(HomeTableViewController(), title: "首页", image: "tabbar_home", selectedImage: "tabbar_home_highlighted")
    addChildViewController(MessageTableViewController(), title: "消息", image: "tabbar_message_center", selectedImage: "tabbar_message_center_highlighted")
    //占个坑位
    addChildViewController(UIViewController())
    addChildViewController(DiscoverTableViewController(), title: "发现", image: "tabbar_discover", selectedImage: "tabbar_discover_highlighted")
    addChildViewController(ProfileTableViewController(), title: "个人", image: "tabbar_profile", selectedImage: "tabbar_profile_highlighted")
  }
  

  //创建按钮
  private lazy var composeBTN : UIButton = {
  let btn = UIButton(type: UIButtonType.Custom)
  btn.setBackgroundImage(UIImage(named: "tabbar_compose_button"), forState: UIControlState.Normal)
  btn.setImage(UIImage(named: "tabbar_compose_icon_add"), forState: UIControlState.Normal)
  btn.addTarget(self, action: "composeClick", forControlEvents: UIControlEvents.TouchUpInside)
  self.tabBar.addSubview(btn)
  return btn
  }()
  func setupComposeBtn(){
  let count = childViewControllers.count
  //计算每个tabbaritem的宽度
  let with = tabBar.bounds.width / CGFloat(count)
  //偏移2个单位
  let rect = CGRect(x: 0, y: 0, width: with, height: tabBar.bounds.height)
  composeBTN.frame = CGRectOffset(rect, with*2, 0)

  }

• 在viewWillAppear中创建按钮懒加载

  override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    setupComposeBtn()
  }
  

按钮点击怎么触发的?

运行循环(runloop) 当没有事件时runloop休眠状态(省电),等待用户输入
一旦用户输入,UIApplicationHandleEventQueue

屏幕快照 2015-11-13 下午12.06.57.png

响应者链条:UIApplication发送事件找到keyWindow->UIcontrol(button)->UIApplication(按钮被点击了,告诉APP,并且按钮注册了监听)->target(告诉target被点击了,快点执行方法)->

@objc 能保证运行循环可以调用,走OC的消息机制,调用之前不再进行判断方法是否存在,和private联用,就能做到对方法的保护

@objc private func composeClick(){
    print(__FUNCTION__)
}

- 利用基类判断用户登录界面逻辑

新需求:增加用户登录界面


loadview 创建实例化根视图,如果根视图不存在系统再次调用loadview

class BaseTableViewController: UITableViewController {
   var islogin = false
    override func loadView() {
        islogin ? super.loadView() : setupUI()
}
private func setupUI(){
    view = UIView()
    view.backgroundColor = UIColor.orangeColor()

      }
   }