使用 Swift 发布 JSON

Question

我使用这个代码，

let username = usernameText.text
let pass = passTxt.text
let pass2 = pass2Txt.text

let myUrl = NSURL(string: "http://192.168.1.6/ff/jsonsignup.php");
let request = NSMutableURLRequest(URL:myUrl!);
request.HTTPMethod = "POST";
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
request.setValue("application/json", forHTTPHeaderField: "Accept")
let postString = "username=\(username)&password=\(pass)&c_password=\(pass2)";

request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding);

let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
    data, response, error in

    if error != nil
    {
        print("error=\(error)")
        return
    }

   print("response = \(response)")

    let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
    print("responseString = \(responseString)")


           let myJSON = try!NSJSONSerialization.JSONObjectWithData(data!, options: .MutableContainers) as! NSDictionary

        if let parseJSON = myJSON as NSDictionary! {

        var firstNameValue = parseJSON["username"] as? String
        print("Username: \(firstNameValue)")
    }

}

task.resume()

响应字符串

Username: {"username":"Optional(\"ttttt\")"}

可选的额外添加短语

但是

我去了，因为我想被派去

{"username":"ttttt"}

不知道哪里出错了？

Answer 1

您获得了 Optional 关键字，因为当您从字典中获取任何数据时，它总是会给您一个 Optional。

Optional 表示它可能包含对象，也可能包含 nil。只是一种更安全的编程方式

使用 if let 语句打开可选的包装

   if let firstNameValue = parseJSON["username"] as? String
   {
      print("Username: \(firstNameValue)")
   }