Ios 如何使用NSNumberFormatter仅显示前两位数字?
我有一个数字,例如1329094。我只想得到我的前两个数字,见13 我创建Ios 如何使用NSNumberFormatter仅显示前两位数字?,ios,swift,swift2,nsnumber,nsnumberformatter,Ios,Swift,Swift2,Nsnumber,Nsnumberformatter,我有一个数字,例如1329094。我只想得到我的前两个数字,见13 我创建NSNumberFormatterlike func setReceivedChart(description: [String], value: [Double]) { var descriptionString: String! var formatterNumber: NSNumber! var chartDataEntryArray = [ChartDataEntr
NSNumberFormatter
like
func setReceivedChart(description: [String], value: [Double]) {
var descriptionString: String!
var formatterNumber: NSNumber!
var chartDataEntryArray = [ChartDataEntry]()
for item in 0..<description.count {
let chartEntry = ChartDataEntry(value: value[item], xIndex: item)
chartDataEntryArray.append(chartEntry)
descriptionString = description[item]
formatterNumber = value[item]
}
let dataSet = LineChartDataSet(yVals: chartDataEntryArray, label: "")
dataSet.drawCircleHoleEnabled = false
dataSet.drawCirclesEnabled = true // change
dataSet.drawCubicEnabled = true
dataSet.drawFilledEnabled = true
dataSet.circleRadius = 3.0 // for iphone
dataSet.drawValuesEnabled = true
print(descriptionString)
let numberFormatter = NSNumberFormatter()
numberFormatter.numberStyle = .NoStyle
numberFormatter.usesSignificantDigits = true
numberFormatter.maximumSignificantDigits = 2
dataSet.valueFormatter = numberFormatter
// set color 47 206 255
dataSet.fillColor = UIColor(red: 47/255, green: 206/255, blue: 255/255, alpha: 1.0)
let chartData = LineChartData(xVals: description, dataSet: dataSet)
receivedChartView.data = chartData
}
func setReceivedChart(说明:[字符串],值:[双精度]){
变量描述字符串:字符串!
var formatterNumber:NSNumber!
var chartDataEntryArray=[ChartDataEntry]()
对于0..中的项,除了NSByteCountFormatter
之外,我不知道有一个数字格式化程序会缩放数字(删除尾随的零)。因此,在将循环中的每个数据点添加到图表数组之前,您需要缩放它。可能是这样的
注意:
仅使用非零有效数字绘制图表似乎非常危险。绘制12、120、1200、12000和120000000000000图表将显示相同的值。
func setReceivedChart(description: [String], value: [Double]) {
let significantFigures = NSNumberFormatter()
significantFigures.usesSignificantDigits = true
significantFigures.maximumSignificantDigits = 2
var chartDataEntryArray = [ChartDataEntry]()
for item in 0..<description.count {
if let datum = significantFigures.stringFromNumber(value[item]) {
datum.stringByReplacingOccurrencesOfString("0", withString: "", options: .LiteralSearch, range: nil)
let chartEntry = ChartDataEntry(value: Double(datum), xIndex: item)
chartDataEntryArray.append(chartEntry)
}
else {
// handle error, keep charDataEntryArray in sync with description[]
}
}
let dataSet = LineChartDataSet(yVals: chartDataEntryArray, label: "")
dataSet.drawCircleHoleEnabled = false
dataSet.drawCirclesEnabled = true // change
dataSet.drawCubicEnabled = true
dataSet.drawFilledEnabled = true
dataSet.circleRadius = 3.0 // for iphone
dataSet.drawValuesEnabled = true
let numberFormatter = NSNumberFormatter()
numberFormatter.numberStyle = .NoStyle
dataSet.valueFormatter = numberFormatter
// set color 47 206 255
dataSet.fillColor = UIColor(red: 47/255, green: 206/255, blue: 255/255, alpha: 1.0)
let chartData = LineChartData(xVals: description, dataSet: dataSet)
receivedChartView.data = chartData
}
func setReceivedChart(说明:[字符串],值:[双精度]){
设有效数字=NSNumberFormatter()
有效数字Figures.usesSignificantDigits=真
有效数字。最大有效数字=2
var chartDataEntryArray=[ChartDataEntry]()
对于0..中的项,除了NSByteCountFormatter
之外,我不知道有一个数字格式化程序会缩放数字(删除尾随的零)。因此,在将循环中的每个数据点添加到图表数组之前,您需要缩放它。可能是这样的
注意:
仅使用非零有效数字绘制图表似乎非常危险。绘制12、120、1200、12000和120000000000000图表将显示相同的值。
func setReceivedChart(description: [String], value: [Double]) {
let significantFigures = NSNumberFormatter()
significantFigures.usesSignificantDigits = true
significantFigures.maximumSignificantDigits = 2
var chartDataEntryArray = [ChartDataEntry]()
for item in 0..<description.count {
if let datum = significantFigures.stringFromNumber(value[item]) {
datum.stringByReplacingOccurrencesOfString("0", withString: "", options: .LiteralSearch, range: nil)
let chartEntry = ChartDataEntry(value: Double(datum), xIndex: item)
chartDataEntryArray.append(chartEntry)
}
else {
// handle error, keep charDataEntryArray in sync with description[]
}
}
let dataSet = LineChartDataSet(yVals: chartDataEntryArray, label: "")
dataSet.drawCircleHoleEnabled = false
dataSet.drawCirclesEnabled = true // change
dataSet.drawCubicEnabled = true
dataSet.drawFilledEnabled = true
dataSet.circleRadius = 3.0 // for iphone
dataSet.drawValuesEnabled = true
let numberFormatter = NSNumberFormatter()
numberFormatter.numberStyle = .NoStyle
dataSet.valueFormatter = numberFormatter
// set color 47 206 255
dataSet.fillColor = UIColor(red: 47/255, green: 206/255, blue: 255/255, alpha: 1.0)
let chartData = LineChartData(xVals: description, dataSet: dataSet)
receivedChartView.data = chartData
}
func setReceivedChart(说明:[字符串],值:[双精度]){
设有效数字=NSNumberFormatter()
有效数字Figures.usesSignificantDigits=真
有效数字。最大有效数字=2
var chartDataEntryArray=[ChartDataEntry]()
对于0..中的项目,为什么不将数字转换为字符串
,去掉不需要的数字并将其转换回去
let number = 1329094
let numberAsString = String(number)
let subString = numberAsString.substringToIndex(numberAsString.startIndex.advancedBy(2))
let trimmedNumber = Int(subString)
或
为什么不将数字转换为字符串
,去掉不需要的数字并将其转换回来呢
let number = 1329094
let numberAsString = String(number)
let subString = numberAsString.substringToIndex(numberAsString.startIndex.advancedBy(2))
let trimmedNumber = Int(subString)
或
请不要包含与您询问的主题不相关的代码。这只会降低相关代码的可视性。请不要包含与您询问的主题不相关的代码。这只会降低相关代码的可视性。请查看请查看,因为图形需要数据,我会测量它们用于构建良好计划的字节数。如果我最初将其转换为不同的值,例如兆字节和字节,则图表中的704字节将超过1.5兆字节。然后您可能需要类似于NSByteCountFormatter
。我无法使用NSByteCountFormatter。我也尝试了它。因为iOS图表库仅支持y NSNumberFormatter我不知道那个库,你在问题中没有提到它。基本上,你不能用NSNumberFormatter从一个数字中去掉最重要的数字。PS:NSValueTransformer
可能会帮助你,因为图形需要数据,我会用字节来测量它们,以构建一个好的时间表。如果我初始化将704字节转换为不同的值,如MB和字节,图表中的704字节将超过1.5 MB。然后您可能需要类似于NSByteCountFormatter
。我无法使用NSByteCountFormatter。我也尝试过。因为iOS图表库只支持NSNumberFormatter,我不知道该库,您也不知道在你的问题中要注意这一点。基本上,你不能用NSNumberFormatter从数字中去掉最重要的数字。PS:NSValueTransformer
可能会对你有所帮助