如何在UIPickerView的每个组件上方设置标题？

Question

我实现了一个带有2个组件的UIPickerview。我想在每个上面设置一个标题。我怎样才能做到这一点？

我不想在拾取器上方放置单独的标签。

Answer 1

 func setHeadersForPickerView() {
    let labelWidth = deliveryPicker.frame.width / CGFloat(deliveryPicker.numberOfComponents)
    for index in 0..<pickerHeaders.count {
        let label: UILabel = UILabel(frame: CGRect(x: deliveryPicker.frame.origin.x + (labelWidth * CGFloat(index)), y: 10, width: labelWidth + 40, height: 20))
        label.text = pickerHeaders[index]
        label.textAlignment = .center
        deliveryPicker.addSubview(label)
    }
}