ios – 在Swift中使用URLComponents编码”

这是我如何将查询参数添加到基本URL：

let baseURL: URL = ...
let queryParams: [AnyHashable: Any] = ...
var components = URLComponents(url: baseURL,resolvingAgainstBaseURL: false)
components?.queryItems = queryParams.map { URLQueryItem(name: $0,value: "\($1)") }
let finalURL = components?.url

当其中一个值包含符号时​​,就会出现问题.由于某种原因,它在最终的URL中没有编码为+,而是保留.如果我自己编码并传递+,则NSURL编码％,’plus’变为％2B.

问题是我如何在NSURL的实例中拥有+？

附：我知道,如果我自己构造一个查询字符串,然后简单地将结果传递给NSURL的构造函数init？(字符串:),我甚至不会遇到这个问题.

解决方法

正如在其他答案中指出的那样,“”字符在
一个查询字符串,这也在
query​Items文档.

另一方面,
W3C recommendations for URI addressing
说明

Within the query string,the plus sign is reserved as shorthand notation for a space. Therefore,real plus signs must be encoded. This method was used to make query URIs easier to pass in systems which did not allow spaces.

这可以通过“手动”构建来实现
百分比编码的查询字符串,使用自定义字符集：

let queryParams = ["foo":"a+b","bar": "a-b","baz": "a b"]
var components = URLComponents()

var cs = CharacterSet.urlQueryAllowed
cs.remove("+")

components.scheme = "http"
components.host = "www.example.com"
components.path = "/somepath"
components.percentEncodedQuery = queryParams.map {
    $0.addingPercentEncoding(withAllowedCharacters: cs)!
    + "=" + $1.addingPercentEncoding(withAllowedCharacters: cs)!
}.joined(separator: "&")

let finalURL = components.url
// http://www.example.com/somepath?bar=a-b&baz=a%20b&foo=a%2Bb

另一种选择是对生成的加号进行“后编码”
百分比编码的查询字符串：

let queryParams = ["foo":"a+b","baz": "a b"]
var components = URLComponents()
components.scheme = "http"
components.host = "www.example.com"
components.path = "/somepath"
components.queryItems = queryParams.map { URLQueryItem(name: $0,value: $1) }
components.percentEncodedQuery = components.percentEncodedQuery?
    .replacingOccurrences(of: "+",with: "%2B")

let finalURL = components.url
print(finalURL!)
// http://www.example.com/somepath?bar=a-b&baz=a%20b&foo=a%2Bb