ios - 循环以获取自定义 NSObject 类 swift 中的数据

Question

嗨，我只是想知道如何从自定义 NSObject 类中提取数据，下面的位置 NSObject 类是我的 NSObject 类(假设数据已经从其他类填充)

import Foundation


class LocationModel: NSObject {

//properties

var name: String?
var address: String?
var latitude: String?
var longitude: String?


//empty constructor

override init()
{

}

//construct with @name, @address, @latitude, and @longitude parameters

init(name: String, address: String, latitude: String, longitude: String) {

    self.name = name
    self.address = address
    self.latitude = latitude
    self.longitude = longitude

}


//prints object's current state

override var description: String {
    return "Name: \(name), Address: \(address), Latitude: \(latitude), Longitude: \(longitude)"

}

}

这是我的循环提取数据(我不知道)

let MapPoint : LocationModel = LocationModel()
for item in MapPoint {

 let name = MapPoint.name
 let latitude = MapPoint.latitude
 let longitude = MapPoint.longitude

print(name, latitude, longtitude)
}

Answer 1

首先，删除默认的初始值设定项并将属性声明为常量和非可选值。好处是编译器将帮助您防止空数据。

class LocationModel: NSObject {

//properties

let name, address, latitude, longitude: String

// construct with @name, @address, @latitude, and @longitude parameters

init(name: String, address: String, latitude: String, longitude: String) {

    self.name = name
    self.address = address
    self.latitude = latitude
    self.longitude = longitude

}

//prints object's current state

override var description: String {
    return "Name: \(name), Address: \(address), Latitude: \(latitude), Longitude: \(longitude)"

}

现在要迭代的对象必须是[LocationModel]类型的数组

let mapPoints = [LocationModel(name:"name1", address:"address1", latitude:"latitude1", longitude:"longitude1"),
                 LocationModel(name:"name2", address:"address2", latitude:"latitude2", longitude:"longitude2"),
                 LocationModel(name:"name3", address:"address3", latitude:"latitude3", longitude:"longitude3")]

for item in mapPoints {

   let name = item.name
   let latitude = item.latitude
   let longitude = item.longitude
   print(name, latitude, longitude)

}

如果地址属性可能丢失，请使用默认值声明初始值设定项并将空字符串视为无值

init(name: String, address: String = "", latitude: String, longitude: String) {...