Question

我正在尝试制作一个水平的UIPickerView。但我的宽度有问题。您可以在

上方的图片顶部找到它

我希望PickerView的宽度为= view.frame.size.width，但由于某种原因，它保持非常小。在我的代码中我有：

let cityPicker = UIPickerView()
var rotationAngle: CGFloat!
let width:CGFloat = 100
let height:CGFloat = 100

override func viewDidLoad() {
        super.viewDidLoad()
cityPicker.delegate = self
        cityPicker.dataSource = self
        cityPicker.frame = CGRect(x: 0, y: 0, width: view.frame.width, height: 50)
        self.view.addSubview(cityPicker)
        rotationAngle = -90 * (.pi/180)
        cityPicker.transform = CGAffineTransform(rotationAngle: rotationAngle)

        }

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

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

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

    func pickerView(_ pickerView: UIPickerView, widthForComponent component: Int) -> CGFloat {
        return 100
    }

    func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView {
        let view = UIView()
        view.frame = CGRect(x: 0, y: 0, width: width, height: height)

        let label = UILabel()
        label.frame = CGRect(x: 0, y: 0, width: width, height: height)
        label.textAlignment = .center
        label.font = UIFont (name: "Baskerville-Bold", size: 30)
        label.text = byer[row]
        view.addSubview(label)

        view.transform = CGAffineTransform(rotationAngle: 90 * (.pi/180))
        return view
    }

谁能看到我做错了什么？

Answer 1

你应该使用autolayout，但是如果你想要手动布局，你就无法在viewDidLoad中使用你的视图框架。此时，框架将与storyboard或nib文件中的框架相同，并且不会反映实际的设备或视图层次结构。您应该将手动调整大小逻辑放在viewDidLayoutSubviews中。调用此函数时，您的视图大小正确，您可以使用它来设置子视图。

Answer 2

var rotationAngle : CGFloat!

在您的ViewDidLoad

rotationAngle = -90 * (.pi / 180 )

在您的课堂上编写此函数

   func rotatePickerView(pickerView : UIPickerView) {
    let y = pickerView.frame.origin.y
    let x = pickerView.frame.origin.x

    pickerView.transform = CGAffineTransform(rotationAngle: rotationAngle)
    pickerView.frame = CGRect(x: x, y: y, width: pickerView.frame.height , height: pickerView.frame.width)
}

此外，我们还需要在旋转pickerview时旋转标签，现在在viewForRow方法中。（这些是Pickerview委托方法。）

let label = UILabel()
    label.font = UIFont(name: "Helvetica", size: 40)
    label.font = UIFont.systemFont(ofSize: 40, weight: .bold)
    label.minimumScaleFactor = 0.5
    label.textAlignment = .center
    label.textColor = UIColor.white
    label.transform = CGAffineTransform(rotationAngle: 90 * (.pi / 180 ))

    //Put your values in an array like Minutes,Temperature etc.
    label.text = minutes[row]

    return label

在viewDidLoad中调用rotatePickerView函数，并将您的pickerview作为参数输入完成，谢谢;）

Answer 3

我不知道@Josh Homann“只使用自动布局”的意思，但是我不得不创建一个旋转的选择器

private let horizontalPickerView: UIPickerView = {
    let view = UIPickerView()
    view.translatesAutoresizingMaskIntoConstraints = false
    view.showsSelectionIndicator = false
    view.transform = CGAffineTransform(rotationAngle: -90 * (.pi / 180))
    return view
}()

然后将其约束设置为凭经验计算

horizontalPickerView.widthAnchor.constraint(equalToConstant: screenWidth),
horizontalPickerView.heightAnchor.constraint(equalToConstant: 300),
horizontalPickerView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
horizontalPickerView.centerYAnchor.constraint(equalTo: mainButton.topAnchor, constant: -32)

，并在UIPickerViewDelegate方法中设置项目的宽度（实际上是高度）

public func pickerView(_ pickerView: UIPickerView, rowHeightForComponent component: Int) -> CGFloat {
    100
}

得到这个

制作水平UIPickerView

3 个答案: