Swift: 如何删除最后一个字符

Question

我正在做一个带有 eureka 表单（costum 行）的应用程序，问题是当我想用 percentageField 计算 firstValue 时计算不正确，因为当我尝试转换为 double 时无法转换 % in double例如：
第一个值 = 34
百分比字段 = 9%
问题是“9%”无法转换为双精度值，值为 0
percentageField*firstValue = 0 因为无法转换 %

代码：

func eingabessumeBruttoCalc(forPercentage isPercentage: Bool){
        let rowEingabessumeBrutto: KalkulationRow = (formViewController()?.form.rowBy(tag:"eingabessumeBrutto"))!
       let rowRabatt: KalkulationRow = (formViewController()?.form.rowBy(tag:"rabatt"))!
        let rowSkonto: KalkulationRow = (formViewController()?.form.rowBy(tag:"skonto"))!
        let rowDiverse: KalkulationRow = (formViewController()?.form.rowBy(tag:"diverse"))!
        let rowZielBrutto:KalkulationRow = (formViewController()?.form.rowBy(tag:"zielBrutto"))!
        let rowZielNetto:KalkulationRow = (formViewController()?.form.rowBy(tag:"zielNetto"))!
        let rowEingabessumeNetto:KalkulationRow = (formViewController()?.form.rowBy(tag:"result"))!

        let ValueEingabessumeBrutto = Double(rowEingabessumeBrutto.cell.valueField.text ?? "") ?? 00
        let ValueEingabessumeNetto = Double(rowEingabessumeNetto.cell.valueField.text ?? "") ?? 00


        let ValueZielBrutto = Double(rowZielBrutto.cell.percentageField.text ?? "")  ?? 00
        let totalZielBrutto = ValueEingabessumeBrutto * ValueZielBrutto * 0.01
        rowZielBrutto.cell.valueField.text = total.description

        let ValueRabatt = Double(rowRabatt.cell.percentageField.text ?? "")  ?? 00
        let totalRabatt = ValueEingabessumeBrutto * ValueRabatt * 0.01
        rowRabatt.cell.valueField.text = total.description

        let SkontoValue = Double(rowSkonto.cell.percentageField.text ?? "")  ?? 00
        let rowsSkonto = Double(rowEingabessumeBrutto)-Double(rowRabatt)
        let totalSkonto = rowSkonto * SkontoValue * 0.01
        rowSkonto.cell.valueField.text = total.description

        let ValueDiverse = Double(rowDiverse.cell.percentageField.text ?? "")  ?? 00
        let totalDierse = ValueEingabessumeBrutto * ValueDiverse * 0.01
        rowDiverse.cell.valueField.text = total.description

        let ValueZielNetto = Double(rowZielNetto.cell.percentageField.text ?? "")  ?? 00
        let totalDierse = ValueEingabessumeNetto * ValueZielNetto * 0.01
        rowZielNetto.cell.valueField.text = total.description

      if let text = percentageField.text,
            !text.isEmpty {
            percentageField.text?.removeLast()

        }

This is what i try.

我想检查最后一个字符是否是 % 删除它。

Answer 1

if let text = textField.text, let lastChar = text.last, lastChar == "%" {
    textField.text = String(text.dropLast())
}

Swift: 如何删除最后一个字符

Swift: How to remove last character

ios

swift

eureka-forms