Swift-CLLocation数组的可编码Decode数组

问题描述

我有一个包含CLLocations数组数组的结构。这是为了支持多折线（换句话说，是一串潜在的不连续线）。我希望对该数据进行编码和解码。我在编写编码和解码方法时遇到了麻烦，因为默认情况下CLLocation无法编码。

    struct MyTrack {
      let coords: [[CLLocation]]?
    
      enum CodingKeys: String,CodingKey {
        case coords
      }
    }

    extension MyTrack: Decodable {
      init(from decoder: Decoder) throws {
        let values = try decoder.container(keyedBy: CodingKeys.self)
        
        coords = try values.decodeIfPresent([[CLLocation]].self,forKey: .coords)?
            .map { ($0 as AnyObject).map { CLLocation(model: $0) } }
    }
}

它当前在Xcode中引发两个错误：

无法将类型“ [[CLLocation]]。Type”的值转换为预期的参数类型“ [Any？]。Type”

“ AnyObject”类型的值没有成员“地图”

任何帮助，不胜感激！

---

---

因为默认情况下CLLocation是不可编码的，所以我按照一个教程在其周围创建包装器结构，代码如下：

extension CLLocation: encodable {
    enum CodingKeys: String,CodingKey {
        case latitude
        case longitude
        case altitude
        case horizontalAccuracy
        case verticalAccuracy
        case speed
        case course
        case timestamp
    }
    public func encode(to encoder: Encoder) throws {
        var container = encoder.container(keyedBy: CodingKeys.self)
        try container.encode(coordinate.latitude,forKey: .latitude)
        try container.encode(coordinate.longitude,forKey: .longitude)
        try container.encode(altitude,forKey: .altitude)
        try container.encode(horizontalAccuracy,forKey: .horizontalAccuracy)
        try container.encode(verticalAccuracy,forKey: .verticalAccuracy)
        try container.encode(speed,forKey: .speed)
        try container.encode(course,forKey: .course)
        try container.encode(timestamp,forKey: .timestamp)
    }
}

struct Location: Codable {
    let latitude: CLLocationdegrees
    let longitude: CLLocationdegrees
    let altitude: CLLocationdistance
    let horizontalAccuracy: CLLocationAccuracy
    let verticalAccuracy: CLLocationAccuracy
    let speed: CLLocationSpeed
    let course: CLLocationDirection
    let timestamp: Date
}

extension CLLocation {
    convenience init(model: Location) {
      self.init(coordinate: CLLocationCoordinate2DMake(model.latitude,model.longitude),altitude: model.altitude,horizontalAccuracy: model.horizontalAccuracy,verticalAccuracy: model.verticalAccuracy,course: model.course,speed: model.speed,timestamp: model.timestamp)
     }
}

解决方法

您正在解码CLLocation，而不是包装器结构。您应该改为解码包装器结构。另外，您不应该投射到AnyObject。

extension MyTrack: Decodable {
    init(from decoder: Decoder) throws {
        let values = try decoder.container(keyedBy: CodingKeys.self)
    
        coords = try values.decodeIfPresent([[Location]].self,forKey: .coords)?
            .map { $0.map(CLLocation.init) }
    }
}