问Swift:点击UITextField时如何显示UIPickerView

EN

import Foundation
import UIKit

class PickerCell: UITableViewCell, UIPickerViewDataSource,UIPickerViewDelegate, UITextFieldDelegate {
@IBOutlet weak var label : UILabel!
@IBOutlet var myPicker: UIPickerView! = UIPickerView()
@IBOutlet weak var selectedData: UITextField!

var pickerData:[String]!

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) {
    self.selectedData.text = self.pickerData[row]
    self.myPicker.hidden = true;
}


func configurePickerCell(labelText:String, enabled:Bool, defaultValueIndex:Int) {
    self.label.text = labelText

    var labelFrame:CGRect = self.label.frame
    labelFrame.size.height = Settings.labelHeight
    self.label.frame = labelFrame

    self.myPicker.delegate = self
    self.myPicker.dataSource = self
    self.selectedData.delegate = self

    self.setEditable(enabled)

}

func setEditable(canEdit:Bool) {

    if (canEdit) {
        self.selectedData.userInteractionEnabled = true
        self.label.highlighted = false
        self.selectedData.layer.borderColor = UIColor(red: 0/255, green: 0/255, blue: 0/255, alpha: 1).CGColor

    }
    else {
        self.selectedData.userInteractionEnabled = false
        self.label.highlighted = true
        self.selectedData.layer.borderColor = UIColor(red: 176/255, green: 176/255, blue: 176/255, alpha: 1).CGColor
    }

}

func textFieldShouldBeginEditing(textField: UITextField) -> Bool {
    self.myPicker.hidden = false
    return false
}


}