Swift - 水平 UIPickerView

Posted 2023-02-24

【中文标题】Swift - 水平 UIPickerView

【英文标题】：Swift - Horizontal UIPickerView

【发布时间】：2020-05-01 18:14:11

【问题描述】：

我正在尝试通过旋转 UIPickerView 然后旋转其中的标签来使用 Swift 制作一个水平选择器，我还尝试旋转其中的视图，而不是标签。

但是在这两种方法中，我得到的结果与图片中显示的相同，选择器内的标签仍未按预期显示。

请看照片和代码， 有关如何解决此问题的任何想法？

@IBOutlet weak var myPicker: UIPickerView!
var rotationAngle: CGFloat!
var pickerArray: [String] = [String]()

override func viewDidLoad() 
    super.viewDidLoad()

    rotationAngle = -90 * (.pi/180)
    myPicker.transform = CGAffineTransform(rotationAngle: rotationAngle)

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

    pickerArray = ["Hello", "World", "What", "Where", "When", "How", "Hey", "Welcome", "Good", "Ok", "Bye", "World!"]

    rotatePickerView(pickerView: myPicker)


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


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


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


func rotatePickerView(pickerView : UIPickerView) 

    myPicker.transform = CGAffineTransform(rotationAngle: rotationAngle)
    myPicker.frame = CGRect(x: -150, y: myPicker.frame.origin.y, width: view.frame.width + 300, height: 200)


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

    let label = UILabel()
    label.font = UIFont(name: "Helvetica", size: 24)
    label.font = UIFont.systemFont(ofSize: 24, weight: .regular)
    label.minimumScaleFactor = 0.5
    label.textAlignment = .center
    label.textColor = UIColor.black
    label.transform = CGAffineTransform(rotationAngle: 90 * (.pi / 180 ))

    label.text = pickerArray[row]

    return label

【问题讨论】：

通过减小字体大小来检查

这不是字体大小问题。

【参考方案1】：

您没有为标签指定框架，即它的宽度和高度。 初始化时需要指定label的frame，通过delegate函数指定view的高度。

func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView 
    
    let pickerRow = UIView()
    pickerRow.frame = CGRect(x: 0, y: 0, width: 100, height: 100)
    let rowLabel = UILabel(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
    rowLabel.textColor = .black
    rowLabel.text = yourData[row]
    rowLabel.textAlignment = .center
    pickerRow.addSubview(rowLabel)
    pickerRow.transform = CGAffineTransform(rotationAngle: 90 * (.pi/180))
    return pickerRow



func pickerView(_ pickerView: UIPickerView, rowHeightForComponent component: Int) -> CGFloat 
    return 100