如何调整 iOS 选择器轮以生成随机索引

Posted 2023-02-24

【中文标题】如何调整 iOS 选择器轮以生成随机索引

【英文标题】：How to adjust iOS picker wheel to generated random Index

【发布时间】：2016-11-28 11:29:16

【问题描述】：

使用 XCode UI 测试有什么方法可以调整 ios 选择轮以生成索引值或获取索引值的文本并调整选择轮。我能够使用以下代码获取索引值。但无法获取索引值的值。

let picker = app.pickerWheels.element(boundBy: 1).otherElements.count
print(picker)
let randomNumber = arc4random_uniform((UInt32(picker)))
print(randomNumber)

使用选择轮的计数，我从中生成一个随机值。使用 randomNumber 的索引号，我试图获取该值。 有什么方法可以获取索引的值并将选择器轮调整为该值。

【参考方案1】：

这就是我在 XCTest UI 测试框架中处理选择器的方式。

我有一个对象 (PickerState)，它可以表示选择轮的状态，它使用选择轮的值填充，格式为 "Some value, 4 of 5"。 getPickerState 方法将值 String 转换为 PickerState 对象。

generateRandomNewPickerPosition 生成一个随机索引供选取器移动到，确保不返回选取器的当前位置。

然后我使用 XCUIElement 上的扩展方法移动到 changePickerSelection 中随机生成的值。

/// Object to represent the state of a picker wheel.
class PickerState 
    let selectedValue: String
    let currentPosition: UInt
    let maximumPosition: UInt

    init(selectedValue: String, currentPosition: UInt, maximumPosition: UInt) 
        self.selectedValue = selectedValue
        self.currentPosition = currentPosition
        self.maximumPosition = maximumPosition
    


/// Retrieve a PickerState object, given the value of a picker wheel.
func getPickerState(_ text: String) 
    // Separate value
    let splitText = text.componentsSeparatedByString(",")
    let selectedValue = splitText[0]

    // Extract numbers
    var numbers = splitText[1].componentsSeparatedByCharactersInSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet)
    numbers = numbers.filter  $0 != "" 
    let currentPosition = UInt(numbers[0])!
    let maximumPosition = UInt(numbers[1])!

    return PickerState(selectedValue: selectedValue, currentPosition: currentPosition, maximumPosition: maximumPosition)


/// Generate a new position (1-indexed) for the picker.
func generateRandomNewPickerPosition(pickerState: PickerState) -> UInt 
    let valueCount = pickerState.maximumPosition
    let random = UInt(arc4random_uniform(UInt32(valueCount - 1)))
    let newPosition = ((pickerState.currentPosition + random) % valueCount) + 1

    return newPosition


/// Move up/down the picker options until the given `selectionPosition` is reached.
func changePickerSelection(pickerWheel: XCUIElement, selectionPosition: UInt) 
    // Select the new value
    var valueSelected = false
    while !valueSelected 
        // Get the picker wheel's current position
        if let pickerValue = pickerWheel.value 
            let currentPosition = UInt(getPickerState(String(pickerValue)).currentPosition)
            switch currentPosition.compared(to: selectionPosition) 
            case .GreaterThan:
                pickerWheel.selectPreviousOption()
            case .LessThan:
                pickerWheel.selectNextOption()
            case .Equal:
                valueSelected = true
            
        
    


/// Extend XCUIElement to contain methods for moving to the next/previous value of a picker.
extension XCUIElement 
    /// Scrolls a picker wheel up by one option.
    func selectNextOption() 
        let startCoord = self.coordinateWithNormalizedOffset(CGVector(dx: 0.5, dy: 0.5))
        let endCoord = startCoord.coordinateWithOffset(CGVector(dx: 0.0, dy: 30.0))
        endCoord.tap()
    

    /// Scrolls a picker wheel down by one option.
    func selectPreviousOption() 
        let startCoord = self.coordinateWithNormalizedOffset(CGVector(dx: 0.5, dy: 0.5))
        let endCoord = startCoord.coordinateWithOffset(CGVector(dx: 0.0, dy: -30.0))
        endCoord.tap()
    


let pickerWheel = app.pickerWheels.element(boundBy: 0)
let newPosition = generateRandomNewPickerPosition(getPickerState(pickerWheel.value))
changePickerSelection(pickerWheel, selectionPosition: newIndex)