swift - 不满足条件时停止按钮

Question

使用 Swift，如果用户输入不正确，我会尝试停止执行按钮？此类的硬编码登录屏幕。有谁可以帮忙吗？

@IBOutlet weak var errorMessage: UILabel!

@IBOutlet weak var user_name: UITextField!

@IBOutlet weak var password: UITextField!


@IBAction func logIn(_ sender: Any, forEvent event: UIEvent) {
    if  user_name.text != "admin" {

        errorMessage.text = "Incorrect username or password"
        print(errorMessage)

    }

Answer 1

只需在显示 errorMessage 后添加 return – 它将立即退出该函数:

@IBAction func logIn(_ sender: Any, forEvent event: UIEvent) {
  if user_name.text != "admin" {
    errorMessage.text = "Incorrect username or password"
    print(errorMessage)
    return
  }
  //...
}