iOS开发之07视图控制器与导航模式

模态视图

在导航过程中，有时候需要放弃主要任务而做其他次要任务，然后在返回到次要任务，这个次要任务就是在模态视图中完成的，如注册中主要任务是登录后进入主界面，如果用户没有注册，就要先去注册，注册是次要任务，当用户注册完成后，它会关闭注册视图，回到登录界面继续进行主要任务。

默认情况下，模态视图是从屏幕下方滑出来的。

负责控制器模态视图的控制器称为模态视图控制器，它并不是一个专门的类，它可以是前面提到的控制器的子类。负责主要任务视图的控制器称为主视图控制器。在UICOntrollerView中，主要有如下两个方法：

• -present():呈现视图
• -dismiss()：关闭视图

在呈现模态视图时有两种方式：一是通过使用UIViewController的present方法实现；二是通过故事板的“过渡”（Segue）实现。

下面我们通过登录案例来介绍模态视图

步骤

1. 创建一个iOS工程，将当前控制器嵌入到一个导航控制器中，具体步骤是：在故事板中选择View Controller，然后点击Xcode菜单栏Editor-Embed In-Navigation Controller菜单就会自动创建一个导航视图
2. 点击导航栏，将导航栏的标题设为登录，然后从对象库中拖入Lable、TextField、Button等控件
3. 接下来设计第二个界面，先从对象库中拖入一个View Controller到设计界面中，然后参考步骤1将该视图控制器嵌入到导航控制器中，修改该导航栏标题为注册，然后从对象库中拖入两个Bar Button Item到导航栏两边，分别设置identifier属性为Cancel和Save
4. 接下来需要在登录场景和注册场景创建一个过渡，按住control键，从登录界面的注册按钮拖鼠标到注册导航控制器，然后松开鼠标，在弹出的视图框中选择Present Modally菜单；它是模态类型的过渡
5. 最后，添加注册控制器类，创建一个类RegisterViewController集成UIViewController，然后回到故事板中将注册视图的Class选择为RegisterViewController

代码实现

ViewController.swift

//
//  ViewController.swift
//  ModalViewSample
//
//  Created by Michael on 2016/11/9.
//  Copyright © 2016年 Michael. All rights reserved.
//

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var mUserName: UITextField!
    override func viewDidLoad() {
        super.viewDidLoad()
        // 注册消息
        NotificationCenter.default.addObserver(self, selector: #selector(self.register(_ :)), name: NSNotification.Name(rawValue: "RegisterCompletion"), object: nil)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
        NotificationCenter.default.removeObserver(self, name: NSNotification.Name.init(rawValue: "RegisterCompletion"), object: nil)
    }
    
    func register(_ notification : Notification) {
        
        let text = notification.userInfo?["username"] as? String
        mUserName.text = text!
        NSLog("%@",text!)
        
    }
}

RegisterViewController.swift

//
//  RegisterViewController.swift
//  ModalViewSample
//
//  Created by Michael on 2016/11/9.
//  Copyright © 2016年 Michael. All rights reserved.
//

import UIKit

class RegisterViewController: UIViewController {

    @IBOutlet weak var mName: UITextField!
    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    @IBAction func save(_ sender: Any) {
        let userInfo = ["username":self.mName.text!]
        //发送消息
        NotificationCenter.default.post(name: NSNotification.Name.init(rawValue: "RegisterCompletion"), object: nil, userInfo: userInfo)
        self.dismiss(animated: true, completion: {
        })
    }
    @IBOutlet weak var save: UIBarButtonItem!
    
    @IBAction func cancel(_ sender: Any) {
        self.dismiss(animated: true, completion: {
        })
    }

}

效果图

分屏导航

基于分屏导航是平铺导航的主要实现方式，涉及的主要控件有分屏控件UIPageControll和屏幕滚动视图UIScrollView,一般不超过10屏

步骤

1. 创建iOS工程，从对象库中拖入UIPageControll和UIScrollView到故事板中，并将其放到合适的位置，UIPageControll放在靠底部，UIScrollView全屏显示，将视图的背景设为黑色
2. 选中UIScrollView的属性检查器，设置不显示Scroll View的Indicator，同时选择滚动Scrolling Enable和分屏Paging Enable。分屏属性是Scroll View每次滑动时翻一屏
3. 选择Page Controll的属性检查器，设置Pages中的of pages总屏数为3，Current当前位置为0，并修改其宽度为300，它的高度是不能修改的。
4. 最后为这两个控件定义输出口并连接注册到ViewController类中，为Page Controll控件定义响应屏幕变化事件的方法。-changPage

代码实现

//
//  ViewController.swift
//  PageControlNavigation
//
//  Created by Michael on 2016/11/10.
//  Copyright © 2016年 Michael. All rights reserved.
//

import UIKit

class ViewController: UIViewController,UIScrollViewDelegate {

    @IBOutlet weak var mScrollView: UIScrollView!
    @IBOutlet weak var mPageControl: UIPageControl!
    
    var mImage1: UIImageView!
    var mImage2: UIImageView!
    var mImage3: UIImageView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        self.mScrollView.delegate = self
        self.mScrollView.contentSize = CGSize(width: self.view.frame.size.width * 3, height: self.mScrollView.frame.size.height)
        self.mScrollView.frame = self.view.frame
        
        self.mImage1 = UIImageView(frame: CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: 480))
        self.mImage1.image = UIImage(named: "达芬奇-蒙娜丽莎")
        self.mScrollView.addSubview(mImage1)
        
        self.mImage2 = UIImageView(frame: CGRect(x: self.view.frame.size.width, y: 0, width: self.view.frame.size.width, height: 480))
        self.mImage2.image = UIImage(named: "罗丹-思想者")
        self.mScrollView.addSubview(mImage2)

        
        self.mImage3 = UIImageView(frame: CGRect(x: self.view.frame.size.width * 2, y: 0, width: self.view.frame.size.width, height: 480))
        self.mImage3.image = UIImage(named: "保罗克利-肖像")
        self.mScrollView.addSubview(mImage3)

        
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    //UIPageControll事件处理
    @IBAction func changePage(_ sender: Any) {
        UIView.animate(withDuration: 0.3, animations: {
            let whichPage = self.mPageControl.currentPage
            //设置内容视图坐标原点与屏幕滚动视图坐原点的偏移量
            self.mScrollView.contentOffset = CGPoint(x: 320 * whichPage, y: 0)
        })
    }
    
    //屏幕滚动视图事件处理方法å
    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        let offset = scrollView.contentOffset
        
        self.mPageControl.currentPage = Int(offset.x) / 320
    }

    

}

效果图

分页控制器

在iOS5以后，我们可以使用分页控制器UIPageViewController构建类似于电子书效果的应用。

分页控制器需要放置在一个父视图控制器中，在分页控制器下面还要有子视图控制器，每个子视图控制器对应一个页面。

UIPageViewController没有对应的视图，我们需要使用代码来实现；需要在UIPageViewController所在的控制器实现UIPageViewControllerDelegate和UIPageViewControllerDataSource协议，UIPageViewControllerDataSource数据源协议必须要实现的方法有以下两个：

• func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController)
• func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController)

UIPageViewControllerDelegate委托协议中一般实现的方法是：

• func pageViewController(_ pageViewController: UIPageViewController, spineLocationFor orientation: UIInterfaceOrientation)
• func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool)

步骤

1. 创建一个iOS工程
2. 代码实现UIPageViewController

代码实现

//
//  ViewController.swift
//  PageNavigation
//
//  Created by Michael on 2016/11/10.
//  Copyright © 2016年 Michael. All rights reserved.
//

import UIKit

enum DirectionFroward : Int {
    
    case Before = 1 //向前
    case After = 2 //向后
    
}

class ViewController: UIViewController,UIPageViewControllerDelegate,UIPageViewControllerDataSource {

    //当前Page的索引
    var mPageIndex = 0
    
    var direct = DirectionFroward.After
    
    var mPageViewController : UIPageViewController!
    var mViewControllers : [UIViewController]!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let pageViewController1 = UIViewController()
        let pageViewController2 = UIViewController()
        let pageViewController3 = UIViewController()
        
        self.mViewControllers = [pageViewController1,pageViewController2,pageViewController3]
        
        let mImage1 = UIImageView(frame: self.view.frame)
        mImage1.image = UIImage(named: "达芬奇-蒙娜丽莎")
        pageViewController1.view.addSubview(mImage1)
        
        let mImage2 = UIImageView(frame: self.view.frame)
        mImage2.image = UIImage(named: "罗丹-思想者")
        pageViewController2.view.addSubview(mImage2)
        
        
        let mImage3 = UIImageView(frame: self.view.frame)
        mImage3.image = UIImage(named: "保罗克利-肖像")
        pageViewController3.view.addSubview(mImage3)
        
        //transitionStyle: pageCurl表示翻书效果样式 scroll 滑屏效果样式
        //navigationOrientation 水平和垂直方向
        self.mPageViewController = UIPageViewController(transitionStyle: .pageCurl, navigationOrientation: .horizontal, options: nil)

        self.mPageViewController.delegate = self
        self.mPageViewController.dataSource = self
        
        //设置首页
        //direction forward向前 reverse向后
        self.mPageViewController.setViewControllers([pageViewController1], direction: .forward, animated: true, completion: nil)
        
        self.view.addSubview(self.mPageViewController.view)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    //DataSource协议
    func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
        NSLog("向前翻")
        mPageIndex -= 1
        
        if mPageIndex < 0 {
            mPageIndex = 0;
            return nil
        }
        
        direct = .Before
        return self.mViewControllers[mPageIndex]
        
    }

    func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
        NSLog("向后翻")

        mPageIndex += 1
        
        if mPageIndex > 2 {
            mPageIndex = 2
            return nil
        }
        
        direct = .After
        return self.mViewControllers[mPageIndex]
        
    }
    
    //Delegate协议
    func pageViewController(_ pageViewController: UIPageViewController, spineLocationFor orientation: UIInterfaceOrientation) -> UIPageViewControllerSpineLocation {
        self.mPageViewController.isDoubleSided = false
        //min和max 首页显示一个视图  mid首页显示两个视图
        return .min
    }


    func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
        
        //翻页未成功
        if completed == false {
            if direct == .After {
                mPageIndex -= 1
            }
            
            if direct == .Before {
                mPageIndex += 1
            }
        }
    }
}

效果图

标签导航

使用标签栏时有一定的指导原则：标签栏位于屏幕下方，占有49个像素屏幕空间，有时可以隐藏起来；标签栏中的标签不能超过5个，如果超过5个则最后一个显示为更多，点击更多标签会出现更多的列表。

步骤

在开发具体应用的时候，标签导航的各个标签分别代表一个功能模块，各功能模块之间相对独立。

1. 创建一个iOS工程模板Tabbed Application应用，默认创建两个标签
2. 从对象库中拖入一个ViewController到故事板中
3. 添加ViewController和Tab Controller Scene的连线，具体操作是：按住control键从Tab Controller Scene拖曳鼠标到ViewController，释放鼠标，从弹出窗口中选择view controllers项即可
4. 设置三个场景的标题
5. 分别为三个场景创建三个视图类

代码实现

//
//  HeiViewController.swift
//  TabNavigation
//
//  Created by Michael on 2016/11/15.
//  Copyright © 2016年 Michael. All rights reserved.
//

import UIKit

class HeiViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}

//
//  JiViewController.swift
//  TabNavigation
//
//  Created by Michael on 2016/11/15.
//  Copyright © 2016年 Michael. All rights reserved.
//

import UIKit

class JiViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}

//
//  LiaoViewController.swift
//  TabNavigation
//
//  Created by Michael on 2016/11/15.
//  Copyright © 2016年 Michael. All rights reserved.
//

import UIKit

class LiaoViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}

效果图

树形导航

树形导航模式是将导航控制器UINavigationController与表视图结使用，主要用于构建从属关系的导航。下面我们创建一个三级视图的树形导航示例。

步骤

1. 创建iOS工程，使用UINavigationController创建以及表视图
2. 创建二级表视图CitiesViewController
   • 从对象库中拖入一个Table View Controller到对象库中作为二级视图控制器
   • 按住control键，从上一个Root View Controller的单元格中拖动鼠标到当前添加的Table View Controller中，释放鼠标，在弹出窗口中选择Show选项
   • 选择连接线中的过渡Segue，打开其属性检查器，然后在Indentifier属性中输入ShowCities
3. 创建三级视图DetailViewController
   • 从对象库中拖入一个View Controller到对象库中作为三级视图控制器
   • 按住control键，从上一个Table View Controller的单元格中拖动鼠标到当前添加的View Controller中，释放鼠标，在弹出窗口中选择Show选项
   • 选择连接线中的过渡Segue，打开其属性检查器，然后在Indentifier属性中输入ShowDetail
4. 设置各级视图的Table View Cell的属性

代码实现

一级视图

//
//  ViewController.swift
//  TreeNavigation
//
//  Created by Michael on 2016/11/15.
//  Copyright © 2016年 Michael. All rights reserved.
//

import UIKit

class ViewController: UITableViewController {
    
    var dictData:NSDictionary!
    var listData:NSArray!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        self.tableView.delegate = self
        self.tableView.dataSource = self
        
        let path = Bundle.main.path(forResource: "provinces_cities", ofType: "plist")
        
        self.dictData = NSDictionary(contentsOfFile: path!)
        self.listData = self.dictData.allKeys as NSArray
        self.title = "省份信息"
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.listData.count
    }
    
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        
        let cell:UITableViewCell! = tableView.dequeueReusableCell(withIdentifier: "Custom", for: indexPath)
        
        let row = indexPath.row
        
        cell.textLabel?.text = self.listData[row] as? String
        
        return cell
    }
    
    //场景过渡之前的处理 点击表视图的单元格触发
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "ShowCities" {
            let indexPath = self.tableView.indexPathForSelectedRow! as IndexPath
            let selectedIndex = indexPath.row
            //获取要跳转到的视图控制器对象
            let controller = segue.destination as! CitiesTableViewController
            let selectName = self.listData[selectedIndex] as! String
            controller.listData = self.dictData[selectName] as! NSArray
            controller.title = selectName
            
        }
    }

}

二级视图

//
//  CitiesTableViewController.swift
//  TreeNavigation
//
//  Created by Michael on 2016/11/15.
//  Copyright © 2016年 Michael. All rights reserved.
//

import UIKit

class CitiesTableViewController: UITableViewController {
    
    var listData:NSArray!

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of rows
        return self.listData.count
    }

    
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell:UITableViewCell! = tableView.dequeueReusableCell(withIdentifier: "CityCell", for: indexPath)
        
        let row = indexPath.row
        let dict = self.listData[row] as! NSDictionary
        cell.textLabel?.text = dict["name"] as? String

        return cell
    }

    //场景过渡之前的与处理
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "ShowDetail" {
            let indexPath = self.tableView.indexPathForSelectedRow! as IndexPath
            let selectIndex = indexPath.row
            let dict = self.listData[selectIndex] as! NSDictionary
            //获取要跳转到的视图控制器对象
            let controller = segue.destination as! DetailViewController
            controller.url = dict["url"] as! String
            controller.title = dict["name"] as? String
        }
    }
}

三级视图

//
//  DetailViewController.swift
//  TreeNavigation
//
//  Created by Michael on 2016/11/15.
//  Copyright © 2016年 Michael. All rights reserved.
//

import UIKit
import WebKit

class DetailViewController: UIViewController,WKNavigationDelegate {
    
    var url:String!
    var webView: WKWebView!

    override func viewDidLoad() {
        super.viewDidLoad()
        NSLog(url)
        self.webView = WKWebView(frame: self.view.frame)
        view.addSubview(webView)
        webView.navigationDelegate = self
        //let nUrl = URL(string: "https://baike.baidu.com/view/2172.htm")
        let mUrl = URL(string: url)
        let request = URLRequest(url: mUrl!)
        webView.load(request)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
        NSLog("开始加载")
    }
    
    func webView(_ webView: WKWebView, didCommit navigation: WKNavigation!) {
        NSLog("内容开始返回时回调")
    }
    
    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        NSLog("加载完成")
    }
    
    func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) {
        NSLog("加载失败")
    }
}

效果图