获取URL参数的值

我正在尝试使用Swift从URL获取参数。假设我有以下网址：

http://mysite3994.com?test1=blah&test2=blahblah

如何获取test1和test2的值？

您可以使用以下代码获取参数

func getQueryStringParameter(url: String, param: String) -> String? {
  guard let url = URLComponents(string: url) else { return nil }
  return url.queryItems?.first(where: { $0.name == param })?.value
}

像这样调用方法 let test1 = getQueryStringParameter(url, param: "test1")

其他扩展方法：

extension URL {
    public var queryParameters: [String: String]? {
        guard
            let components = URLComponents(url: self, resolvingAgainstBaseURL: true),
            let queryItems = components.queryItems else { return nil }
        return queryItems.reduce(into: [String: String]()) { (result, item) in
            result[item.name] = item.value
        }
    }
}

第1步：创建URL扩展

extension URL {
    func valueOf(_ queryParamaterName: String) -> String? {
        guard let url = URLComponents(string: self.absoluteString) else { return nil }
        return url.queryItems?.first(where: { $0.name == queryParamaterName })?.value
    }
}

步骤2：如何使用扩充功能

let newURL = URL(string: "http://mysite3994.com?test1=blah&test2=blahblah")!

newURL.valueOf("test1") // Output i.e "blah"
newURL.valueOf("test2") // Output i.e "blahblah"

我还做了一个URL扩展，但是将查询参数查找放入下标中。

extension URL {
    subscript(queryParam:String) -> String? {
        guard let url = URLComponents(string: self.absoluteString) else { return nil }
        return url.queryItems?.first(where: { $0.name == queryParam })?.value
    }
}

用法：

let url = URL(string: "http://some-website.com/documents/127/?referrer=147&mode=open")!

let referrer = url["referrer"]  // "147"
let mode     = url["mode"]      // "open"

链接指向在Angular上创建的网站时，似乎没有现有答案可用。这是因为Angular的路径通常#在所有链接中都包含一个（哈希）符号，这将导致url.queryItems始终返回nil。

如果链接看起来像这样： http://example.com/path/#/morepath/aaa?test1=blah&test2=blahblah

然后只能从中获取参数url.fragment。在@Matt的扩展中添加了一些附加的解析逻辑后，通用代码将如下所示：

extension URL {
    subscript(queryParam: String) -> String? {
        guard let url = URLComponents(string: self.absoluteString) else { return nil }
        if let parameters = url.queryItems {
            return parameters.first(where: { $0.name == queryParam })?.value
        } else if let paramPairs = url.fragment?.components(separatedBy: "?").last?.components(separatedBy: "&") {
            for pair in paramPairs where pair.contains(queryParam) {
                return pair.components(separatedBy: "=").last
            }
            return nil
        } else {
            return nil
        }
    }
}

用法保持不变：

let url = URL(string: "http://example.com/path/#/morepath/aaa?test1=blah&test2=blahblah")!

let referrer = url["test1"]  // "blah"
let mode     = url["test2"]  // "blahblah"

这样做的另一种方法是在URL上创建扩展名以返回组件，然后在[URLQueryItem]上创建扩展名以从queryItems中检索值。

extension URL {
    var components: URLComponents? {
        return URLComponents(url: self, resolvingAgainstBaseURL: false)
    }
}

extension Array where Iterator.Element == URLQueryItem {
    subscript(_ key: String) -> String? {
        return first(where: { $0.name == key })?.value
    }
}

这是如何使用它的一个示例：

if let urlComponents = URL(string: "http://mysite3994.com?test1=blah&test2=blahblah")?.components,
    let test1Value = urlComponents.queryItems?["test1"] {
    print(test1Value)
}