UIPickerView 不允许通过委托的 `attributedTitleForRow...` 更改字体名称和大小答案

【问题标题】：UIPickerView won't allow changing font name and size via delegate's `attributedTitleForRow...`UIPickerView 不允许通过委托的 `attributedTitleForRow...` 更改字体名称和大小
【发布时间】：2015-02-11 20:31:07
【问题描述】：

我使用以下函数来更改字体颜色和字体大小，颜色有效，但字体名称和字体大小拒绝工作。

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

var myTitle = NSAttributedString(string: titleData, attributes: [NSFontAttributeName:UIFont(name: "Arial-BoldMT", size: 45)!, NSForegroundColorAttributeName:UIColor.whiteColor()])

有什么帮助吗？

谢谢。

【问题讨论】：

不只是在 Swift 中...
iOS 9 beta 5 上的同样问题
在带有 Swift 4.1 和 Xcode 9.4.1 的 iOS 11.4 中仍然无法使用。也许是时候提交错误了。
iOS 12 也不行。
iOS 15 签入；还是不行。

标签： cocoa fonts size uipickerview nsattributedstring

【解决方案1】：

我有另一个选择可能对你有帮助..

完成正常选择器视图所需的所有工作：获取更多帮助UIPickerView make in Swift iOS

现在按照这个步骤： - 你可以像这样使用 viewForRow 的方法

func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView!) -> UIView
{
    var pickerLabel = UILabel()
    pickerLabel.textColor = UIColor.blackColor()
    pickerLabel.text = "PickerView Cell Title"
   // pickerLabel.font = UIFont(name: pickerLabel.font.fontName, size: 15)
    pickerLabel.font = UIFont(name: "Arial-BoldMT", size: 15) // In this use your custom font
    pickerLabel.textAlignment = NSTextAlignment.Center
    return pickerLabel
}

更新了 Swift 3

func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView!) -> UIView
{
    let pickerLabel = UILabel()
    pickerLabel.textColor = UIColor.black
    pickerLabel.text = "PickerView Cell Title"
    // pickerLabel.font = UIFont(name: pickerLabel.font.fontName, size: 15)
    pickerLabel.font = UIFont(name: "Arial-BoldMT", size: 15) // In this use your custom font
    pickerLabel.textAlignment = NSTextAlignment.center
    return pickerLabel
}

更新了 Swift 5

func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView
    {
        let pickerLabel = UILabel()
        pickerLabel.textColor = UIColor.white
        pickerLabel.text = "PickerView Cell Title"
        // pickerLabel.font = UIFont(name: pickerLabel.font.fontName, size: 15)
        pickerLabel.font = UIFont.boldSystemFont(ofSize: 20) // In this use your custom font
        pickerLabel.textAlignment = NSTextAlignment.center
        return pickerLabel
    }

可能对你有帮助，我在我的项目中也使用了它。

【讨论】：

是的，您的代码有效。但我需要从 pickerView(pickerView, titleForRow: row, forComponent: component) 中获取重新计算的标题数据。顺便问一下，我如何在评论中发布代码？
pickerView(_:titleForRow:forComponent:)
pickerView(_:attributedTitleForRow:forComponent:)
pickerView(_:viewForRow:forComponent:reusingView:)
以上三个也可以显示pickerview的内容，但不要同时使用，我以某种方式使用其中两个。现在只使用最后一个，问题就解决了。
谢谢大家。

【解决方案2】：

你可以为pickerview声明数据源

let arrDataSource:[String] = ["row 1","row 2","row 3"]

然后使用这个字符串数组作为下面函数中行的标题

func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView!) -> UIView

{
    let pickerLabel = UILabel()
    pickerLabel.textColor = UIColor.blackColor()
    pickerLabel.text = arrDataSource[row]
     pickerLabel.font = UIFont(name: pickerLabel.font.fontName, size: 15)
    //pickerLabel.font = UIFont(name: "Arial-BoldMT", size: 15) // In this use your custom font
    pickerLabel.textAlignment = NSTextAlignment.Center
    return pickerLabel
 }

【讨论】：

【解决方案3】：

SWIFT 3

func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView {

    var string = ""

    let pickerLabel = UILabel()
    pickerLabel.textColor = UIColor.white
    pickerLabel.text = string
    pickerLabel.font = UIFont(name: "Rubik-Regular", size: 22) // In this use your custom font
    pickerLabel.textAlignment = .center

    return pickerLabel

}

【讨论】：

【解决方案4】：

要进一步详细说明 https://stackoverflow.com/users/4020910/bennythenerd 对 UILabel 的回答，我会采用更多内存优化的解决方案来重用标签：

func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView {
    let pickerLabel: UILabel
    if let label = view as? UILabel {
        pickerLabel = label
    } else {
        pickerLabel = UILabel()
        pickerLabel.font = UIFont(name: "Rubik-Regular", size: 22)
        pickerLabel.textAlignment = .center
    }
    pickerLabel.text = pickerData[row] //This is your string
    return pickerLabel
}

【讨论】：

这是正确的方法。

【解决方案5】：

Swift 4.1 / Xcode 9.4.1

显然您可以选择自己的字体，但这里我使用的是 System Bold 13。

func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView {
    let pickerLabel = UILabel()
    pickerLabel.font = UIFont.boldSystemFont(ofSize: 13)
    pickerLabel.textColor = UIColor.black
    pickerLabel.textAlignment = .center
    pickerLabel.text = "PickerView Cell Title"

    return pickerLabel
}

【讨论】：