访问按钮目标抛出错误

Accessing Button Target Throwing Error

使用下面的代码,当我按下按钮时出现错误。我不确定 why.The 错误是无法识别的选择器发送到实例并以 "terminating with uncaught exception of type NSException." 终止任何帮助肯定会受到赞赏。 谢谢

class WordSearchWindow: UIViewController {

let boardsize = 10

override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(false)
    buttonGridder()
}

func buttonGridder() {
    for x in 0..<self.boardsize {
        for y in 0..<self.boardsize{
            let sizer = ButtonGrid.frame.width
            let buttonSize:CGFloat = sizer / CGFloat(self.boardsize)
            let letterButton = WordButton(column: x, row: y, buttonSize: buttonSize, buttonMargin: 0)
            letterButton.addTarget(self, action: "letterFirst", forControlEvents: .TouchDown)
            letterButton.addTarget(self, action: "letterSecond", forControlEvents: .TouchUpInside)
            self.ButtonGrid.addSubview(letterButton)
        }
    }
}

func letterFirst(sender: WordButton) {
    print("hello1")
}

func letterSecond(sender: WordButton) {
    print("hello2")
}
}

试试这个:

letterButton.addTarget(self, action: "letterFirst:", forControlEvents: .TouchDown)
letterButton.addTarget(self, action: "letterSecond:", forControlEvents: .TouchUpInside)

在动作中添加: