swift-MVVM设计模式

mvvm设计模式之前在oc中有讲过，现在就不在介绍了。
现在用swift语法直接上代码。

首先看下架构情况,model-View-viewModel-controller。

1. model:->GameModel

import UIKit
class GameModel: NSObject,NSCoding {

var cname: String = ""
var ename: String = ""
var img: String = ""
var ext: String = ""
var status: Int?
var cdn_rate: Int?

init(dict: [String: Any]) {
    super.init()
    setValuesForKeys(dict)
}

override func setValue(_ value: Any?, forUndefinedKey key: String) {}

// MARK:- 处理需要归档的字段
func encode(with aCoder:NSCoder) {
    aCoder.encode(cname, forKey:"cname")
    aCoder.encode(ename, forKey:"ename")
    aCoder.encode(img, forKey:"img")
    aCoder.encode(ext, forKey:"ext")
    aCoder.encode(status, forKey:"status")
    aCoder.encode(cdn_rate, forKey:"cdn_rate")
}

// MARK:- 处理需要解档的字段
required init(coder aDecoder:NSCoder) {
    super.init()
    cname = (aDecoder.decodeObject(forKey:"cname")as? String)!
    ename = (aDecoder.decodeObject(forKey:"ename")as? String)!
    img = (aDecoder.decodeObject(forKey:"img")as? String)!
    ext = (aDecoder.decodeObject(forKey:"ext")as? String)!
    status = aDecoder.decodeObject(forKey:"status")as? Int
    cdn_rate = aDecoder.decodeObject(forKey:"cdn_rate")as? Int
}

override init() {
    super.init()
}
}

2. view->CollectionGameCell.swift

     import UIKit
    class CollectionGameCell: UICollectionViewCell {
   
    @IBOutlet weak var imageView: UIImageView!
   
    @IBOutlet weak var nameLabel: UILabel!
   
      var gameModel: GameModel? {
   
    didSet {
    
        guard let iconURL = URL(string: gameModel?.img ?? "") else {
            return
        }
        imageView.kf.setImage(with: iconURL)
        nameLabel.text = gameModel?.cname
    }
    }
   
   }
   

---> CollectionGameCell.xib

1.png

3. viewModel->GameVM
   一般来说，在创建viewmodel时会先给一个基础的baseViewModel，与网络请求连用.这里的数据类型简单，就直接用GameVM了。
   import UIKit
   class GameVM: NSObject {
   lazy var gameArray: [GameModel] = GameModel

     func loadGameData(finishedCallback : @escaping () -> ()) {
    NetworkTool.request(type: .GET, urlString: "http://api.m.panda.tv/index.php", paramters: ["method":"category.list", "type":"game", "__version":"1.1.7.1305", "__plat":"ios", "__channel":"appstore"]) { (result) in
        guard let resultDict = result as? [String: NSObject] else { return }
        guard let dataArray = resultDict["data"] as? [[String: NSObject]] else { return }
        for dict in dataArray {
            self.gameArray.append(GameModel(dict: dict))
        }
        finishedCallback()
    }
    }
   }
   

当然除了这些还需要有网络请求模块.

这里我是用pod导入第三方框架。pod 'Alamofire'
封装了一个网络请求的类
NetworkTool.swift
import UIKit
import Alamofire

enum MethodType {
case GET
case POST
 }


class NetworkTool {

class func request(type: MethodType, urlString: String, paramters: [String: Any]? = nil, finishedCallback: @escaping (_ result: Any) -> ()) {
    // 获取类型
    let method = type == .GET ? HTTPMethod.get : HTTPMethod.post
    // 发送网络请求
    Alamofire.request(urlString, method: method, parameters: paramters).responseJSON { (response) in
        guard let result = response.result.value else {
            print(response.result.error)
            return
        }
        // 回调
        finishedCallback(result as AnyObject)
    }
}
}

4. controller ->GameVC.swift

   import UIKit
   private let kGameItemMargin : CGFloat = 4
   private let kItemW = (kScreenW - kGameItemMargin * 4) / 3
   private let kItemH = kScreenW / 2
   private let kGameCellID = "kGameCellID"
   
    class GameVC: UIViewController {
   
     fileprivate lazy var gameArray = [GameModel]()
     fileprivate lazy var gameVM:GameVM = {
   
    let model = GameVM()
    return model
    }()
    //懒加载属性
   
      fileprivate lazy var collectionView:UICollectionView = {
   
    [unowned self] in
    
    let layout = UICollectionViewFlowLayout()
    layout.itemSize = CGSize(width: kItemW, height:kItemH)
    layout.minimumLineSpacing = kGameItemMargin
    layout.minimumInteritemSpacing = kGameItemMargin
    layout.sectionInset = UIEdgeInsets(top: kGameItemMargin, left:kGameItemMargin,bottom:kGameItemMargin,right:kGameItemMargin)
    let collectionView = UICollectionView(frame:self.view.bounds,collectionViewLayout:layout)
    collectionView.backgroundColor = BGCOLOR
    collectionView.dataSource = self
    collectionView.delegate = self
    collectionView.autoresizingMask = [.flexibleHeight, .flexibleWidth]
    collectionView.register(UINib(nibName: "CollectionGameCell", bundle: nil), forCellWithReuseIdentifier: kGameCellID)
    return collectionView
    
    }()
   
    override func viewDidLoad() {
    super.viewDidLoad()
   
    view.backgroundColor = UIColor.white
    self.title = "游戏"
    setupUI()
    requestData()
   }
   }
   //遵循协议(用扩展方式分类出来)
   extension GameVC: UICollectionViewDataSource,UICollectionViewDelegate {
   
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return gameVM.gameArray.count
    }
   
   func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: kGameCellID, for: indexPath) as! CollectionGameCell
    cell.backgroundColor = UIColor.white
    cell.gameModel = gameVM.gameArray[indexPath.item]
    return cell
    }
   
    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    
    //点击cell 跳转控制器
    let moreVC = MoreLivingVC()
    let model = gameVM.gameArray[indexPath.item]
    moreVC.cateName = model.ename
    moreVC.title = model.cname
    self.navigationController?.pushViewController(moreVC, animated: true)
    }
   }
   

   //创建UI和请求数据
   extension GameVC {

   //MARK 设置UI
   fileprivate func setupUI() {

    view.addSubview(collectionView)
   

   }

   //MARK 发送网络请求
   fileprivate func requestData() {

    //mvc模式请求数据成功
   

   // NetworkTool.request(type: .GET, urlString: "http://api.m.panda.tv/index.php", paramters: ["method":"category.list", "type":"game", "__version":"1.1.7.1305", "__plat":"ios", "__channel":"appstore"]) { (result) in
   // guard let resultDict = result as? [String: NSObject] else { return }
   // guard let dataArray = resultDict["data"] as? [[String: NSObject]] else { return }
   // for dict in dataArray {
   // self.gameArray.append(GameModel(dict: dict))
   // }
   // self.collectionView.reloadData()
   // }

    //mvvm模式,回调刷新成功
    gameVM.loadGameData() {
        
        self.collectionView.reloadData()
       
    }
   

   }
   }
   运行结果如图:

2.png

在这里我用了mvc和mvvm两种模式做比较，在网络请求上区别不大,mvvm较mvc模式而言，将model层和数据请求封装到一个类中，在controller看不到请求数据，直接调用返回数据类型得到数据.