Swift - 标签条（UITabBar）标签页控制器（UITabBarController）用法

   

1，使用storyboard设计标签页

2，使用代码实现标签条（TabBar）

import UIKit

class ViewController: UIViewController,UITabBarDelegate {
    
    //添加Tab Bar控件
    var tabBar:UITabBar!
    //Tab Bar Item的名称数组
    var tabs = ["公开课","全栈课","设置"]
    //Tab Bar上方的容器
    var contentView:UIView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        //在底部创建Tab Bar
        tabBar = UITabBar(frame:CGRect(x:0, y:self.view.bounds.height - 50,
                   width:self.view.bounds.width, height:50))
        var items:[UITabBarItem] = []
        for tab in self.tabs {
            let tabItem = UITabBarItem()
            tabItem.title = tab
            items.append(tabItem)
        }
        //设置Tab Bar的标签页
        tabBar.setItems(items, animated: true)
        //本类实现UITabBarDelegate代理，切换标签页时能响应事件
        tabBar.delegate = self
        //代码添加到界面上来
        self.view.addSubview(tabBar);
        
        //上方的容器
        contentView = UIView(frame: CGRect(x:0, y:0, width:self.view.bounds.width,
                                           height:self.view.bounds.height-50))
        self.view.addSubview(contentView)
        let lbl = UILabel(frame:CGRect(x:100, y:200, width:100, height:20))
        //定义tag，在用户切换tab时能查询到label控件
        lbl.tag = 1
        contentView.addSubview(lbl)
    }
    
    // UITabBarDelegate协议的方法，在用户选择不同的标签页时调用
    func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {
        //通过tag查询到上方容器的label，并设置为当前选择的标签页的名称
        (contentView.viewWithTag(1) as! UILabel).text = item.title
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}

3，使用代码实现标签页控制器（TabBarController）

         

import UIKit

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let button = UIButton(type: .system)
        button.frame = CGRect(x:100, y:150, width:100, height:30)
        button.setTitle("开始游戏", for:.normal)
        button.addTarget(self, action:#selector(ViewController.tapped),
                         for:.touchUpInside)
        self.view.addSubview(button);
    }
    
    func tapped(){
        self.present(MainTabViewController(), animated:true, completion:nil)
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}

import UIKit

class MainTabViewController:UITabBarController
{
    override func viewDidLoad()
    {
        super.viewDidLoad()
        //一共包含了两个视图
        let viewMain = MainViewController()
        viewMain.title = "2048"
        let viewSetting = SettingViewController()
        viewSetting.title = "设置"
        
        //分别声明两个视图控制器
        let main = UINavigationController(rootViewController:viewMain)
        main.tabBarItem.image = UIImage(named:"first")
        //定义tab按钮添加个badge小红点值
        main.tabBarItem.badgeValue = "!"
        
        let setting = UINavigationController(rootViewController:viewSetting)
        setting.tabBarItem.image = UIImage(named:"second")
        self.viewControllers = [main,setting]
        
        //默认选中的是游戏主界面视图
        self.selectedIndex = 0
    }
}

import UIKit

class MainViewController: UIViewController {
    
    override func viewDidLoad() {
        
        super.viewDidLoad()
        //改成主视图背景白色背景
        self.view.backgroundColor = UIColor.white
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}

import UIKit

class SettingViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = UIColor(red:109/255, green:218/255,
                                            blue:255/255, alpha:1)
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}