如何将原始字典转换为 JSON 字符串？

Question

我有这种类型的字典：

{
    “event”: {
        “type”: “message_create”, “message_create”: {
            “target”: {
                “recipient_id”: “RECIPIENT_USER_ID”
            }, “message_data”: {
                “text”: “Hello World!”,
            }
        }
}

我想将此字典转换为 JSON 字符串格式，但无法做到。请任何人指导我。

这是代码，直到我在发送消息后尝试我从服务器收到错误的身份验证数据消息 -

 func sendMessage(_ userInfo: String) {

        let requestURL = URL(string: "https://api.twitter.com/1.1/direct_messages/events/new.json")
        Alamofire.request(requestURL!, method: .post,
                          encoding: URLEncoding.default,
                          headers: getRequestHeader()).responseJSON { (response) in
                            print(response)

                            switch response.result {
                            case .success:
                                print("Validation Successful")
                            case .failure(let error):
                                print("FAILURE ERROR : \(error.localizedDescription)")
                                print("ERROR : \(error)")
                                if let data = response.data {
                                    print("Print Server Error: " + String(data: data, encoding: String.Encoding.utf8)!)
                                }
                            }

        }
    }

    // MARK: - Get Request Header
    func getRequestHeader() -> ([String: String]) {

        return ["authorization": "","CONSUMER_KEY":"",
                "CONSUMER_SECRET":"",
                "oauth_secret":"7W2Gx4KEjz7d164NPvJaOktzhaSPpV3VNjvyjpIqaDc02",
                "oauth_token":"2605063830-IffuOmn2tEajFXY6khbzmeMwNoUvGkQ8qrYonzw",
                "oauth_version":"1.0",
                "oauth_signature_method":"HMAC-SHA1",
                "Content-Type": "application/json"
        ]
    }

Answer 1

为了专注于获取 json 字符串（而不关心您如何获得字典），我假设您的 myDict 是您要转换为 json 字符串的字典：

let json = """
{
    "event": {
        "type": "message_create", "message_create": {
            "target": {
                "recipient_id": "RECIPIENT_USER_ID"
            },
            "message_data": {
                "text": "Hello World!"
            }
        }
    }
}
""".data(using: .utf8)

var myDict: [String: Any] = [: ]

do {
    if let dict = try JSONSerialization.jsonObject(with: json!, options: []) as? [String: Any] {
        myDict = dict
    }
} catch {
    print(error)
}

所以现在我们要将myDict转换为json字符串：

do {
    // converting `myDict` to Json Data, and then
    // getting our json as string from the `jsonData`:
    if let jsonData = try JSONSerialization.data(withJSONObject: myDict, options: []) as? Data,
       let jsonString = String(data: jsonData, encoding: .utf8) {
        print(jsonString)
    }
} catch {
    print(error)
}

jsonString 现在就是你要找的东西！你应该在日志上看到：

{"event":{"type":"message_create","message_create":{"target":{"recipient_id":"RECIPIENT_USER_ID"},"message_data":{"text":"你好 世界！"}}}}

这是完全有效的 json。

Answer 2

public extension NSDictionary{

    public func toJSONString() -> String{
        if JSONSerialization.isValidJSONObject(self) {
            do{
                let data = try JSONSerialization.data(withJSONObject: self, options: JSONSerialization.WritingOptions(rawValue: 0))

                if let string = NSString(data: data, encoding: String.Encoding.utf8.rawValue) {
                    return string as String
                }
            }catch {
                print("error")
            }
        }
        return ""
    }
}