我有一個作為引數傳入的 ClosedRange，現在我需要將其轉換為 ClosedRange：
let range: ClosedRange<Int>
init(range: ClosedRange<Int>) {
self.range = range
}
var body: some View {
Slider(value: doubleBinding, in: range.startIndex...range.endIndex, step: 1)
}
Slider init 函式采用 ClosedRange 引數。所以我得到了這個錯誤：
Cannot convert value of type 'ClosedRange<Int>.Index' to expected argument type 'Double'
所以我嘗試了這個：
let min = Double(Int(range.startIndex))
let max = Double(Int(range.endIndex))
Slider(value: doubleBinding, in: min...max, step: 1)
但是得到了這個錯誤：
Initializer 'init(_:)' requires that 'ClosedRange<Int>.Index' conform to 'BinaryInteger'
uj5u.com熱心網友回復：
您使用了錯誤的屬性。不是startIndex和endIndex。它是lowerBound和upperBound：
Slider(value: doubleBinding,
in: Double(range.lowerBound)...Double(range.upperBound),
step: 1)
您可以撰寫一個ClosedRange方便地執行此操作的初始化程式：
extension ClosedRange {
init<Other: Comparable>(_ other: ClosedRange<Other>, _ transform: (Other) -> Bound) {
self = transform(other.lowerBound)...transform(other.upperBound)
}
}
用法：
Slider(value: doubleBinding,
in: ClosedRange(range, Double.init),
step: 1)
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