Swift实现前缀功能

1. 需要先定义一个 泛型结构体;用来存储传入的值
2. 定义RouterCompatible接口，并给这个接口扩展默认实现,使不论是类还是对象,只要遵守了这个接口，那么都能够获取到Router示例
3. 在给任何类添加前缀的时候，只需要遵守这个接口，拓展自己想要实现的逻辑即可。

struct Router<T> {
    var base: T
    init(_ base:T) {
        self.base = base
    }
}

protocol RouterCompatible {}

extension RouterCompatible {
    var router: Router<Self> {
        get { Router(self) }
        set {} /* 规定: 必须写*/
    }
    static var router:Router<Self>.Type {
        get {Router<Self>.self}
        set {}
    }
}

假设给NSViewController 添加Route 功能：

enum RouterType {
    case normal // via windowCtl
    case modalWindow
    case sheet
}
extension NSViewController: RouterCompatible {}

//extension Router where T == NSViewController { //不要约定死,否则其子类不能调用
extension Router where T: NSViewController {
    func show(ctrl: NSViewController, type routerType: RouterType = .normal){
        switch routerType {
        case .normal:
            let vc = ctrl
            let window = NSWindow(contentViewController: vc)
            window.styleMask = [.titled, .closable, .resizable]
            window.setContentSize(.init(width: Helper.ui.app_width, height: Helper.ui.app_height))
    //        window.setFrame(.init(x: 0, y: 0, width: Helper.ui.app_width, height: Helper.ui.app_height), display: true)
//            window.title = title
            let windowCtl = NSWindowController(window: window)
            windowCtl.showWindow(self.base)
        case .modalWindow:
//            ctrl.title = "DDDD"
            self.base.presentAsModalWindow(ctrl)
        case .sheet:
            self.base.presentAsSheet(ctrl)
        } 
    }
}

使用流程如下: 在ViewController 中调用

@IBAction func ctl_transfrom(_ sender: Any) {
    let btn = sender as! NSButton
    
    let tag = btn.tag
    
    switch tag {
    case 0:
        let vc = NormalCtl()
        vc.title = "Normal Ctl"
        self.router.show(ctrl: vc)
        
    case 1:

        let vc = ModalCtl()
        vc.title = "Modal Ctl 1"
        self.router.show(ctrl: vc, type: .modalWindow)
        
    case 2:
        let vc = ModalCtl()
        vc.title = "Modal Ctl 2"
        self.router.show(ctrl: vc, type: .sheet)
        
    case 3:
        
        let vc = TableViewCtl()
        vc.title = "TableViewCtl"
        self.router.show(ctrl: vc)
    default:
        break
    }
}