iOS MVVM模式
MVVM如图，是为了解决MVC在大项目里VC变得臃肿的模式
典型的MVC就如写个简单的TableView，逻辑都扔到VC里
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| class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
let tableView: UITableView = {
let tableView = UITableView()
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
return tableView
}()
let data = ["1", "2", "3"]
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(tableView)
tableView.delegate = self
tableView.dataSource = self
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
tableView.frame = view.bounds
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = data[indexPath.row]
return cell
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
data.count
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
}
}
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随着Data的变化，抽取出ViewModel这一概念，使得cell的数据和视图的更新多了一层
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| struct User {
let name: String
let nation: String
}
struct CellViewModel {
let name: String
let nation: String
}
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
let tableView: UITableView = {
let tableView = UITableView()
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
return tableView
}()
let data = [
User(name: "haoboxuxu", nation: "China"),
User(name: "Batman", nation: "Gotham"),
User(name: "Hopper X", nation: "Space"),
]
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(tableView)
tableView.delegate = self
tableView.dataSource = self
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
tableView.frame = view.bounds
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
let model = data[indexPath.row]
let viewModel = CellViewModel(name: model.name, nation: model.nation)
cell.textLabel?.text = "\(viewModel.name) \(viewModel.nation)"
return cell
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
data.count
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
}
}
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你可能觉得这样和MVC没什么大区别，但是到了如果要自定义cell或者其他自定义视图的场景就更加展现出用途
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|
class CustomCell: UITableViewCell {
@IBOutlet weak var nameLabel: UILabel!
@IBOutlet weak var nationLabel: UILabel!
static let cellID = "CustomCell"
static func nib() -> UINib {
return UINib(nibName: "CustomCell", bundle: nil)
}
override func awakeFromNib() {
super.awakeFromNib()
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
}
func configWith(_ vm: CellViewModel) {
nameLabel.text = vm.name
nationLabel.text = vm.nation
}
}
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
let tableView: UITableView = {
let tableView = UITableView()
tableView.register(CustomCell.nib(), forCellReuseIdentifier: CustomCell.cellID)
return tableView
}()
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: CustomCell.cellID, for: indexPath) as! CustomCell
let model = data[indexPath.row]
let viewModel = CellViewModel(name: model.name, nation: model.nation)
cell.configWith(viewModel)
return cell
}
}
|
当当！
