iOS -错误类型“ViewController”不符合“UIPickerViewDataSource”协议

Question

我做了很多研究，但找不到解决问题的办法。这是我第一年的斯威夫特，所以请不要“太先进”。

这是我的密码：

class SecondViewController: UIViewController, UITextFieldDelegate, UIPickerViewDataSource, UIPickerViewDelegate {
    // Properties
    @IBOutlet weak var name_tf: UITextField!
    @IBOutlet weak var artist_tf: UITextField!
    @IBOutlet weak var sort_pkr: UIPickerView!
    @IBOutlet weak var sort_lbl: UILabel!
    @IBOutlet weak var sorted_lbl: UILabel!
    @IBOutlet weak var next_lbl: UILabel!

    let pickerData = ["Song name","Artist"]

    func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
        return 1
    }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return pickerData.count
    }

    func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return pickerData[row]
    }

    func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        sort_lbl.text = pickerData[row]
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        let pickerView = UIPickerView()
        pickerView.delegate = self
        pickerView.dataSource = self
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

我有一种感觉，我没有把我的功能放在正确的位置。

Answer 1

对于Swift 3，请使用以下函数：

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {

   }
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {

   }