1、直接通過String的format格式化
val formatString = "%.2f"
2、通過DecimalFormat格式化
val decimal = DecimalFormat("#.##")
decimal.format(processingFeePer)
3、通過NumberFormat
val numberFormat = NumberFormat.getInstance().apply {
maximumFractionDigits = 2
roundingMode = RoundingMode.UNNECESSARY
}
val format = numberFormat.format(processingFee)