php - 发布请求总是由可选文本包裹

Question

我有一个与 Why the http post request body always wrapped by Optional text in the Swift app 非常相似的问题但我无法将此线程中的解决方案应用到我的代码中，因为我没有 request.setValue。有谁知道我需要做什么才能摆脱 Optional？我的代码:

 @IBAction func LoginButtonTapped(sender: UIButton) {

    let username = UsernameTextField.text
    let password = PasswordTextField.text

    if(username!.isEmpty || password!.isEmpty) {return; }



    let request = NSMutableURLRequest (URL: NSURL(string: "http://myip/loginregister.php")!)
    request.HTTPMethod = "POST"
    let postString = "username=\(username)&password=\(password)"
    request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)
    let task = NSURLSession.sharedSession().dataTaskWithRequest(request) { data, response, error in
        guard error == nil && data != nil else {
            // check for fundamental networking error
            print("error=\(error)")
            return
        }

        let data = postString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!



        do {
            if let json = try NSJSONSerialization.JSONObjectWithData(data, options: []) as? NSDictionary {
                let success = json["success"] as? Int                                  // Okay, the `json` is here, let's get the value for 'success' out of it
                print("Success: \(success)")
            } else {
                let jsonStr = NSString(data: data, encoding: NSUTF8StringEncoding)    // No error thrown, but not NSDictionary
                print("Error could not parse JSON: \(jsonStr)")
            }
        } catch let parseError {
            print(parseError)                                                          // Log the error thrown by `JSONObjectWithData`
            let jsonStr = NSString(data: data, encoding: NSUTF8StringEncoding)
            print("Error could not parse JSON: '\(jsonStr)'")
        }
    }

    task.resume()

Answer 1

首先从 UITextField 获取文本时必须解包值，因为 UITextField 的 text 属性允许 nil

let username = UsernameTextField.text!
let password = PasswordTextField.text!

解释更多

当您打开 UITextField 的 text 时，username 和 password 将是 not nil 变量。比较空的代码应该是:

if(username.isEmpty || password.isEmpty) {return }

如果你不解包，当你使用这个"\(username)"时，你试图将一个nil对象转换成字符串，所以字符串结果将附加“可选”文本。

解决请求的Content-Type问题

将此行粘贴到您的代码中。我不相信你没有 setValue 方法。

request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField:"Content-Type")