如何將文本字段的值傳遞給Swift中的按鈕單擊函數？

Question

我需要在按下登錄按鈕時執行用戶名和登錄檢查。 我需要在沒有故事板的情況下完成所有這些工作。 但是，我的問題是，當我創建一個連接到函數的按鈕時，文本字段就超出了范圍。

override func viewDidLoad（）{super.viewDidLoad（）

        let Login = UIButton()
        makeButton(Login, name: "Login", location: CGRectMake((screenSize.width-120)/2, 5*screenSize.width/6, 120, 30))
        Login.addTarget(self, action: "loginChecks", forControlEvents: .TouchUpInside)


        // Makes Text Fields
        let usernameField: UITextField = UITextField()
        makeTextField(usernameField, frame: CGRectMake((screenSize.width-300)/2 + 300, 175, 300, 35))

        let passwordField: UITextField = UITextField()
        makeTextField(passwordField, frame: CGRectMake((screenSize.width-300)/2 + 300, 350, 300, 35))

        // Makes Text Labels
        let usernameLabel: UILabel = UILabel()
        makeLabel(usernameLabel, name: "Username", frame: CGRectMake((screenSize.width-300)/2 - 300, 175, 300, 55))

        let passwordLabel: UILabel = UILabel()
        makeLabel(passwordLabel, name: "Password", frame: CGRectMake((screenSize.width-300)/2 - 300, 350, 300, 55))

        self.configureView()

    }

**這是ViewDidLoad **之外的單獨功能**

func loginChecks(){
            // Checks login logic

inputsPassword和inputsUsername都顯示在范圍之外

            var inputtedPassword = passwordField.text
            var inputtedUsername = usernameField.text
            print(inputtedUsername)
            print(inputtedPassword)

            if (inputtedUsername == ""){
                makeAlert("No Username", message: "Please input a username.", printStatement: "No username")
                return
            } else if(inputtedPassword == ""){
                makeAlert("No Password", message: "Please input a password.", printStatement: "No password")
                return
            } else {

            }

        }

Answer 1

您應該將usernameField和passwordField聲明為類中的屬性，這樣您就可以從多個方法訪問它們。 例如：

class ViewController: UIViewController {

let usernameField: UITextField = UITextField()
let passwordField: UITextField = UITextField()

override func viewDidLoad() {
    super.viewDidLoad()

    let Login = UIButton()
    makeButton(Login, name: "Login", location: CGRectMake((screenSize.width-120)/2, 5*screenSize.width/6, 120, 30))
    Login.addTarget(self, action: "loginChecks", forControlEvents: .TouchUpInside)


    // Makes Text Fields
    makeTextField(usernameField, frame: CGRectMake((screenSize.width-300)/2 + 300, 175, 300, 35))

    makeTextField(passwordField, frame: CGRectMake((screenSize.width-300)/2 + 300, 350, 300, 35))

    // Makes Text Labels
    let usernameLabel: UILabel = UILabel()
    makeLabel(usernameLabel, name: "Username", frame: CGRectMake((screenSize.width-300)/2 - 300, 175, 300, 55))

    let passwordLabel: UILabel = UILabel()
    makeLabel(passwordLabel, name: "Password", frame: CGRectMake((screenSize.width-300)/2 - 300, 350, 300, 55))

    self.configureView()
}

func loginChecks(){
    // Checks login logic
    var inputtedPassword = passwordField.text
    var inputtedUsername = usernameField.text
    print(inputtedUsername)
    print(inputtedPassword)

    if (inputtedUsername == ""){
        makeAlert("No Username", message: "Please input a username.", printStatement: "No username")
        return
    } else if(inputtedPassword == ""){
        makeAlert("No Password", message: "Please input a password.", printStatement: "No password")
        return
    } else {

    }
}

}