在swift中将php文件中的字符串分配给UIlabel

Question

我有一个响应字符串从服务器上的php文件返回到我的xcode应用程序。反正我是否可以将响应字符串的文本分配给UIlabel的文本？

我的代码是：

@IBOutlet weak var usernameTxt: UITextField!
@IBOutlet weak var passwordTxt: UITextField!
@IBOutlet weak var emailTxt: UITextField!
@IBOutlet weak var firstnameTxt: UITextField!
@IBOutlet weak var lastnameTxt: UITextField!
@IBOutlet weak var usernameLbl: UILabel!


@IBAction func TextFieldEditingDidChange(_ sender: Any) {
    let request = NSMutableURLRequest(url: NSURL(string: "usernamecheck.php")! as URL)
    request.httpMethod = "POST"
    print("Request: \(request)")
    let postString = "username=\(usernameTxt.text!)"
    request.httpBody = postString.data(using: String.Encoding.utf8)
    let task = URLSession.shared.dataTask(with: request as URLRequest) {
        data, response, error in
        if error != nil {
            print("error=\(error)")
            return
        } // Ends errror If statements
        print("response = \(response)")
        let responseString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue)
        print("responseString = \(responseString)")

    } // Ends let task
    task.resume()

}