ios - 创建一种更简洁的方法来设置具有多个 init 的结构？

Question

我目前有一个结构体，有多种初始化方法。目前它有效，我只是想知道是否有更干净的方法来创建结构？在这里:

    struct Destination {
    var name: String? = "Unkown"
    var waypoint: JMapWaypoint?

    init(destination: JMapDestination) {
        self.name = destination.name
        self.waypoint = destination.waypoints?.first
    }


    init (waypoint: JMapWaypoint) {
        self.waypoint = waypoint
        self.name = "Shared Location"

    }


    init(point: CGPoint, name: String, mapController: JMapController){
        self.name = name
        let pointToJMapPoint = JMapPoint.init(x: Float(point.x),
                                                  y: Float(point.y),
                                                  z: Float(mapController.userLocation.mapId))


        self.waypoint = mapController.getNearestWaypoint(with: pointToJMapPoint ?? JMapPoint())
    }
}

Answer 1

我不知道你理解的清洁是什么意思。有很多方法可以减少代码中的 init。您可以给它们一个默认值，例如，或者创建一些名为 DestinationParams 的其他结构，其中将包含您需要的所有参数。

struct Destination {
    private (set) var name: String
    private (set) var waypoint: JMapWaypoint?

    init(destination: JMapDestination? = nil) {
        self.init(name: destination?.name ?? "Shared Location",
                  waypoint: destination?.waypoints?.first)
    }

    init(name: String, point: JMapPoint? = JMapPoint(), mapController: JMapController) {
        let waypoint = mapController.getNearestWaypoint(with: point)
        self.init(name: name,
                  waypoint: waypoint)
    }

    private init(name: String, waypoint: JMapWaypoint?) {
        self.waypoint = waypoint
        self.name = name
    }
}

或者，您可以通过将所有计算移到 init 之外来修改它，如下所示:

...
let pointToJMapPoint = JMapPoint.init(x: Float(point.x),
                                      y: Float(point.y),
                                      z: Float(mapController.userLocation.mapId))
let point = mapController.getNearestWaypoint(with: pointToJMapPoint ?? JMapPoint())
let x = Destination(name: "Some name", waypoint: point)
...
struct Destination {
    private (set) var name: String
    private (set) var waypoint: JMapWaypoint?

    init(destination: JMapDestination? = nil) {
        self.init(name: destination?.name ?? "Shared Location",
                  waypoint: destination?.waypoints?.first)
    }

    init(name: String, waypoint: JMapWaypoint?) {
        self.waypoint = waypoint
        self.name = name
    }
}

这一切都取决于您，取决于您想要什么。