当我触摸任何按钮时，我的应用程序崩溃了

Question

How to use the selector in Utility Class and there definition? My code create some error. PLease tell me how to resolve this error?

Error : My app crashed when I touched on any button.

class BarButton{
    static func items(navigationItem: UINavigationItem) {
        //Hide Back Button
        navigationItem.hidesBackButton = true

        //Add Label to Left of NavigationBar
        let leftLabel = UIBarButtonItem(title: "", style: .plain, target: self, action: nil)
        leftLabel.tintColor = UIColor.init(red: 30/255, green: 104/255, blue: 140/255, alpha: 1)
        navigationItem.setLeftBarButton(leftLabel, animated: false)

        //List Button
        let btnList = UIButton(frame: CGRect(x: 0, y: 0, width: 35, height: 22))
        btnList.setImage(UIImage(named:"list-icn"), for: .normal)
        btnList.addTarget(self, action: #selector(listBtn), for: .touchUpInside)
        let rightBarBtn1 = UIBarButtonItem.init(customView: btnList)
        rightBarBtn1.tintColor = UIColor(red: 30/255, green: 104/255, blue: 140/255, alpha: 1)

        //Notification Button
        let btnList2 = UIButton(frame: CGRect(x: 0, y: 0, width: 22, height: 22))
        btnList2.setImage(UIImage(named:"notification-icn"), for: .normal)
        btnList2.addTarget(self, action: #selector(notificationBtn), for: .touchUpInside)
        let rightBarBtn2 = UIBarButtonItem.init(customView: btnList2)
        rightBarBtn2.tintColor = UIColor(red: 30/255, green: 104/255, blue: 140/255, alpha: 1)
        navigationItem.setRightBarButtonItems([rightBarBtn1, rightBarBtn2], animated: true)
    }

    @objc func listBtn() {
        print("List Btn")
    }

    @objc func notificationBtn() {
        print("Notification Btn")
    }
}

Answer 1

Try this and see:

let btnList = UIButton(frame: CGRect(x: 0, y: 0, width: 35, height: 22))
btnList.setImage(UIImage(named:"list-icn"), for: .normal)

// Update selector
btnList.addTarget(self, action: #selector(BarButton.listBtn(sender:)), for: .touchUpInside)
let rightBarBtn1 = UIBarButtonItem.init(customView: btnList)
rightBarBtn1.tintColor = UIColor(red: 30/255, green: 104/255, blue: 140/255, alpha: 1)


//Notification Button
let btnList2 = UIButton(frame: CGRect(x: 0, y: 0, width: 22, height: 22))
btnList2.setImage(UIImage(named:"notification-icn"), for: .normal)

// Update selector
btnList2.addTarget(self, action: #selector(BarButton.notificationBtn(sender:)), for: .touchUpInside)
let rightBarBtn2 = UIBarButtonItem.init(customView: btnList2)
rightBarBtn2.tintColor = UIColor(red: 30/255, green: 104/255, blue: 140/255, alpha: 1)
navigationItem.setRightBarButtonItems([rightBarBtn1, rightBarBtn2], animated: true)


// Try using static
@objc static func listBtn(sender: Any)
{
    print("List Btn")
}

// Try using static
@objc static func notificationBtn(sender: Any)
{
    print("Notification Btn")
}

Answer 2

Your listBtn and notificationBtn methods are instance methods, but you try to invoke them on a class, not class instance - your items method is static , so self inside of it is of AnyObject.Type type.

To fix it, make listBtn and notificationBtn methods static.