如何在swift 3中使用URL構造url（string：，relativeTo :)

Question

我想在swift 3中構造一個url，但我不明白爲什麼它不會將字符串附加到baseURL正確的輸出不是我所期望的。在swift 2中，它工作正常。

let token = "12token34" 

let baseURL = URL(string: "https://api.mysite.net/map/\(token)/") 

let desiredURL = URL(string: "37.8267,-122.4233", relativeTo: baseURL as URL?) 

結果

37.8267,-122.4233 -- https://api.mysite.net/map/12token34/ 

我期待下面：

https://api.mysite.net/map/12token34/37.8267,-122.4233 

Answer 1

let token = "12token34" 
let baseURL = URL(string: "https://api.mysite.net/map/\(token)/") 
let desiredURL = URL(string: "37.8267,-122.4233", relativeTo: baseURL as URL?) 

這是錯誤的原因：

/// Initialize with string, relative to another URL. 
/// 
/// Returns `nil` if a `URL` cannot be formed with the string (for example, if the string contains characters that are illegal in a URL, or is an empty string). 
public init?(string: String, relativeTo url: URL?) 

所以，如果你想添加的url，輸出應該是這樣的：

let output = URL(string: baseURL!.absoluteString) 
output?.appendingPathComponent("37.8267,-122.4233") 

這樣你就可以直接使用：

baseURL!.appendingPathComponent("37.8267,-122.4233")