更改选取器视图中的字体颜色

Question

我正在创建货币转换器应用程序。应该使用选择器视图选择货币，所有数据都已经在里面。我的选择器视图字体当前是黑色的，但我想让它变成白色。如何更改字体的颜色（不是背景）？

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

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

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

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

    price_kind = pickerViewSource[row]
    switch price_kind {
    case "USD":
        label.text = "$  " + price_kind
        rate = 1.0
    case "EUR":
        label.text = "€  " + price_kind
        rate = 0.9461
    case "GBP":
        label.text = "£  " + price_kind
        rate = 0.8017
    case "RUB":
        label.text = "₽  " + price_kind
        rate = 64.3435
    case "CNY":
        label.text = "¥  " + price_kind
        rate = 6.9137
    case "YEN":
        label.text = "¥  " + price_kind
        rate = 6.26
    case "AUD":
        label.text = "$  " + price_kind
        rate = 1.3498
    case "CAD":
        label.text = "$  " + price_kind
        rate = 1.3483
    default:
        label.text = "$  " + price_kind
        rate = 1.0


    }

Answer 1

要更改UIPickerView 中的文本，请使用NSAttributedString：

func pickerView(_ pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {
    let str = pickerData[row]
    return NSAttributedString(string: str, attributes: [NSForegroundColorAttributeName:UIColor.white])
}

Answer 2

你可以使用 attributesTitleForRow 和 NSAttributedString

请参考以下代码。

func pickerView(pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {
    let attributedString = NSAttributedString(string: "some string", attributes: [NSForegroundColorAttributeName : UIColor.redColor()])
    return attributedString
}

如果您希望每行具有不同的颜色，请使用以下代码。

func pickerView(pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {
        var attributedString: NSAttributedString!

        switch component {
        case 0:
            attributedString = NSAttributedString(string: "Zero", attributes: [NSForegroundColorAttributeName : UIColor.redColor()])
        case 1:
            attributedString = NSAttributedString(string: "One", attributes: [NSForegroundColorAttributeName : UIColor.redColor()])
        case 2:
            attributedString = NSAttributedString(string: "Two"), attributes: [NSForegroundColorAttributeName : UIColor.redColor()])
        default:
            attributedString = nil
        }

        return attributedString
    }