Question

任何人都可以建议清洁工是从CLPlacemark创建一个地址字符串。

目前我正在使用此扩展程序

extension CLPlacemark {

    func makeAddressString() -> String {
        var address = ""
        if subThoroughfare != nil { address = address + " " + subThoroughfare! }
        if thoroughfare != nil { address = address + " " + thoroughfare! }
        if locality != nil { address = address + " " + locality! }
        if administrativeArea != nil { address = address + " " + administrativeArea! }
        if postalCode != nil { address = address + " " + postalCode! }
        if country != nil { address = address + " " + country! }
        return address
    }
}

所有实例变量都是可选项，因此检查为nil，我想按街道号，街道等的顺序排列。

Answer 1

你现在可以在一个Optionals数组上进行flatMap以过滤掉nil值（我认为这可以从Swift 2开始）。您的示例现在基本上是单行（如果您删除我为了可读性而插入的换行符）：

extension CLPlacemark {

    func makeAddressString() -> String {
        return [subThoroughfare, thoroughfare, locality, administrativeArea, postalCode, country]
            .flatMap({ $0 })
            .joined(separator: " ")
    }
}

您可以更进一步，并使用嵌套数组来实现更复杂的样式。以下是德语缩写地址（MyStreet 1, 1030 City）的示例：

extension CLPlacemark {

    var customAddress: String {
        get {
            return [[thoroughfare, subThoroughfare], [postalCode, locality]]
                .map { (subComponents) -> String in
                    // Combine subcomponents with spaces (e.g. 1030 + City),
                    subComponents.flatMap({ $0 }).joined(separator: " ")
                }
                .filter({ return !$0.isEmpty }) // e.g. no street available
                .joined(separator: ", ") // e.g. "MyStreet 1" + ", " + "1030 City"
        }
    }
}

Answer 2

这也应该有用。

extension CLPlacemark {

  func makeAddressString() -> String {
    // Unwrapping the optionals using switch statement
    switch (self.subThoroughfare, self.thoroughfare, self.locality, self.administrativeArea, self.postalCode, self.country) {
    case let (.Some(subThoroughfare), .Some(thoroughfare), .Some(locality), .Some(administrativeArea), .Some(postalCode), .Some(country)):
        return "\(subThoroughfare), \(thoroughfare), \(locality), \(administrativeArea), \(postalCode), \(country)"
    default:
        return ""
    }
  }
}

查看此帖子以供参考： http://natashatherobot.com/swift-unwrap-multiple-optionals/

编辑 - 这只有在没有任何选项为零时才有效，如果一个是零，则情况不匹配。检查参考链接，了解如何检测可能为零的情况。

从CLPlacemark创建地址字符串

2 个答案: