以下 curl 有效

curl -G -H "api_key: MYAPIKEY" https://api.semantics3.com/test/v1/products -d 'q={"upc":"70411576937"}'

但是，在尝试将其转换为 iOS 时出现以下错误:

Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost." {NSErrorFailingURLStringKey=https://api.semantics3.com/test/v1/products,...}

我在下面附上了我的代码，但我认为我的问题是在提交到 URL 的 json 数据之前的“q=”。如果是这样，这叫什么以及如何在我的 json 数据之前放置“q=”？不过，由于 iOS 始终如一地向我们提供不相关的错误消息，我无法准确判断。谢谢。

    var urlString = "https://api.semantics3.com/test/v1/products"
    var request = NSMutableURLRequest(URL: NSURL(string: urlString)!)
    var response: NSURLResponse?
    var error: NSErrorPointer = nil
    var reqText = ["upc": "70411576937"]
    var err: NSError?

    request.HTTPBody = NSJSONSerialization.dataWithJSONObject(reqText, options: nil, error: &err)
    request.HTTPMethod = "GET"
    request.addValue("MYAPIKEY", forHTTPHeaderField: "api_key")
    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")
    var session = NSURLSession.sharedSession()

    var task = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in
        var strData = NSString(data: data, encoding: NSUTF8StringEncoding)
        if(err != nil) {
            println(err!.localizedDescription)
        }
        else {
            //this is where the error is printed
            println(error)
            var parseError : NSError?
            // parse data
            let unparsedArray: AnyObject? = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.AllowFragments, error: &parseError)
            println(parseError)
            if let resp = unparsedArray as? NSDictionary {
                println(resp)
            }
        }
    })
    task.resume()

最佳答案

正文不用于 GET http 方法。使用以下代码连接您的参数:

extension String {

    /// Percent escape value to be added to a URL query value as specified in RFC 3986
    ///
    /// This percent-escapes all characters besize the alphanumeric character set and "-", ".", "_", and "~".
    ///
    /// http://www.ietf.org/rfc/rfc3986.txt
    ///
    /// :returns: Return precent escaped string.

    func stringByAddingPercentEncodingForURLQueryValue() -> String? {
        let characterSet = NSMutableCharacterSet.alphanumericCharacterSet()
        characterSet.addCharactersInString("-._~")

        return self.stringByAddingPercentEncodingWithAllowedCharacters(characterSet)
    }

}

extension Dictionary {

    /// Build string representation of HTTP parameter dictionary of keys and objects
    ///
    /// This percent escapes in compliance with RFC 3986
    ///
    /// http://www.ietf.org/rfc/rfc3986.txt
    ///
    /// :returns: String representation in the form of key1=value1&key2=value2 where the keys and values are percent escaped

    func stringFromHttpParameters() -> String {
        let parameterArray = map(self) { (key, value) -> String in
            let percentEscapedKey = (key as! String).stringByAddingPercentEncodingForURLQueryValue()!
            let percentEscapedValue = (value as! String).stringByAddingPercentEncodingForURLQueryValue()!
            return "\(percentEscapedKey)=\(percentEscapedValue)"
        }

        return join("&", parameterArray)
    }

}


var urlString = "https://api.semantics3.com/test/v1/products"
var reqText = ["upc": "70411576937"]
var err: NSError?

let parameterString = reqText.stringFromHttpParameters()
let requestURL = NSURL(string:"\(urlString)?\(parameterString)")!

var request = NSMutableURLRequest(URL: NSURL(string: urlString)!)
var response: NSURLResponse?
var error: NSError?

request.HTTPMethod = "GET"
request.addValue("MYAPIKEY", forHTTPHeaderField: "api_key")
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
var session = NSURLSession.sharedSession()

部分编辑:SWIFT 2.1(更新)

extension Dictionary {

    func stringFromHttpParameters() -> String {
        let parameterArray = self.map { (key, value) -> String in
            let percentEscapedKey = (key as! String).stringByAddingPercentEncodingForURLQueryValue()!
            let percentEscapedValue = (value as! String).stringByAddingPercentEncodingForURLQueryValue()!
            return "\(percentEscapedKey)=\(percentEscapedValue)"
        }

        return parameterArray.joinWithSeparator("&")
    }

}

关于ios - 将 curl 命令转换为 iOS，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/30720714/