带有url参数的Swift GET请求

我正在构建一个调查，当用户回答一个问题时，我会将答案附加到带有参数的url字符串中，并向我的服务器发送get请求。因此，对于每个答案，都有一个由所选答案、时间戳和调查的唯一id组成的记录

我不确定做这件事的最佳方式，但这就是我目前所拥有的

我创建url和查询项

var urlComponents: URLComponents {

    let resultID = surveyQuestions.resultId
    print("\(String(describing: resultID))")

    let resultResponseID = surveyQuestions.questions[surveyResultResponseId]
    print("\(String(describing: resultResponseID))")

    let questionIndex = questionNumbers
    print("\(String(describing: questionIndex))")

    var urlComponents = URLComponents(string: "My String URL")

    urlComponents?.queryItems = [
        URLQueryItem(name: "surveyResultsId", value: "\(String(describing: resultID))"),
        URLQueryItem(name: "surveyResultsResponseId", value: "\(String(describing: resultResponseID))"),
        URLQueryItem(name: "questions", value: "\(questionIndex)"),
        URLQueryItem(name: "selectedAnswer", value: "\(storedAnswer)")

    ] 

    let url = urlComponents?.url

    print(url!.absoluteString as Any)

    return urlComponents!
}

然后我构建发送请求

func sendRequest(_ url: String, parameters: [String: String], completion: @escaping ([String: Any]?, Error?) -> Void) {

    var components = URLComponents(string: url)!
    components.queryItems = parameters.map { (key, value) in
        URLQueryItem(name: key, value: value)
    }

    components.percentEncodedQuery = components.percentEncodedQuery?.replacingOccurrences(of: "+", with: "%2B")
    let request = URLRequest(url: components.url!)

    let task = URLSession.shared.dataTask(with: request) { data, response, error in
        guard let data = data, // is there data
            let response = response as? HTTPURLResponse, // is there HTTP response
            (200 ..< 300) ~= response.statusCode, // is statusCode 2XX
            error == nil else { // was there no error, otherwise ...
                completion(nil, error)
                return
        }

        let responseObject = (try? JSONSerialization.jsonObject(with: data)) as? [String: Any]
        completion(responseObject, nil)
        print("This is the \(responseObject!)")
    }
    task.resume()
}

---

现在，当我运行此命令时，我会返回带有查询项的字符串，但当我运行send请求时，我会得到未知错误。我觉得我好像做错了什么事。对于“use responseObject here”区域，我应该在其中添加什么内容。我有点困惑。另外，当我调用send请求时，我应该在参数值中输入什么。现在，它们只是参数：[“”：“”]。我觉得我好像很亲近。非常感谢您的帮助。

首先，您所做的工作比可能需要的多得多。您正在将查询字符串参数编码为

URLComponents

，这是正确的。然后，在发送中，您将分解URL并解析出组件，然后对其重新编码。你也在做大量的强制展开，这是脆弱的，隐藏了问题

下面是你在操场上简化的代码，对我来说很有用：

import UIKit
import PlaygroundSupport

PlaygroundPage.current.needsIndefiniteExecution = true

let sampleURL = "https://someserver.com/somepath"

func sendRequest(_ url: URL, completion: @escaping ([String: Any]?, Error?) -> Void) {

    let task = URLSession.shared.dataTask(with: url) { data, response, error in
        guard let data = data, // is there data
            let response = response as? HTTPURLResponse, // is there HTTP response
            (200 ..< 300) ~= response.statusCode, // is statusCode 2XX
            error == nil else { // was there no error, otherwise ...
                completion(nil, error)
                return
        }
        let responseObject = (try? JSONSerialization.jsonObject(with: data)) as? [String: Any]
        completion(responseObject, nil)
    }
    task.resume()
}

var urlComponents: URLComponents? {

    let resultID = "resultID123"
    let resultResponseID = "responseID456"
    let questionIndex = "questionNumbers1"

    var urlComponents = URLComponents(string: sampleURL)
    urlComponents?.queryItems = [
        URLQueryItem(name: "surveyResultsId", value: "\(String(describing: resultID))"),
        URLQueryItem(name: "surveyResultsResponseId", value: "\(String(describing: resultResponseID))"),
        URLQueryItem(name: "questions", value: "\(questionIndex)"),
        URLQueryItem(name: "selectedAnswer", value: "\("storedAnswer1")")

    ]
    return urlComponents
}

if let urlComponents = urlComponents, let url = urlComponents.url?.absoluteURL {
    sendRequest(url) { (result, error) in
        print("Got an answer: \(String(describing: result))")
    }
}

---

谢谢你的快速回复。对于if let urlcomponents=urlcomponents，我发现这个错误“let”不能嵌套在另一个“var”或“let”模式中。不知道为什么。当我将if let urlComponents=urlComponents，let url=urlComponents.url？.absoluteURL{sendRequest（url）{（result，error）打印（“获得答案：（String（description:result））”）}放在我的answerPressed按钮中时，它工作正常。我还注意到发送请求时得到的响应不包括url和urlqueryitems。它只返回一个可选响应，不包含urlcomponents.URLQueryItems只是一个用于将参数编码到查询字符串中的构造。当您在URL组件上调用“absoluteURL”时，它会将所有组件编码到URL本身（例如）。如果需要，您可以随时恢复它们，但它们都在那里。有没有办法删除它们？在queryitems之前？我尝试在sampleUrl上使用replacingOccurrences（of:“？”，with:”），但这不起作用。您是否错过了

~=

重载的代码，或者它本身可以工作？

import UIKit
import PlaygroundSupport

PlaygroundPage.current.needsIndefiniteExecution = true

let sampleURL = "https://someserver.com/somepath"

func sendRequest(_ url: URL, completion: @escaping ([String: Any]?, Error?) -> Void) {

    let task = URLSession.shared.dataTask(with: url) { data, response, error in
        guard let data = data, // is there data
            let response = response as? HTTPURLResponse, // is there HTTP response
            (200 ..< 300) ~= response.statusCode, // is statusCode 2XX
            error == nil else { // was there no error, otherwise ...
                completion(nil, error)
                return
        }
        let responseObject = (try? JSONSerialization.jsonObject(with: data)) as? [String: Any]
        completion(responseObject, nil)
    }
    task.resume()
}

var urlComponents: URLComponents? {

    let resultID = "resultID123"
    let resultResponseID = "responseID456"
    let questionIndex = "questionNumbers1"

    var urlComponents = URLComponents(string: sampleURL)
    urlComponents?.queryItems = [
        URLQueryItem(name: "surveyResultsId", value: "\(String(describing: resultID))"),
        URLQueryItem(name: "surveyResultsResponseId", value: "\(String(describing: resultResponseID))"),
        URLQueryItem(name: "questions", value: "\(questionIndex)"),
        URLQueryItem(name: "selectedAnswer", value: "\("storedAnswer1")")

    ]
    return urlComponents
}

if let urlComponents = urlComponents, let url = urlComponents.url?.absoluteURL {
    sendRequest(url) { (result, error) in
        print("Got an answer: \(String(describing: result))")
    }
}

Got an answer: Optional(["image": {
    href = "https://example.com";
}, "object_types": {
    card =     {
        fields =         {
        };
        pollable = 1;
    };
}])