[英]How to use a NumberFormatter in SwiftUI?
I'm trying to use the below NumberFormatter
but can't figure out how to use it in a Text
view?我正在尝试使用下面的
NumberFormatter
但不知道如何在Text
视图中使用它? Everything online relates to a TextView
.网上的一切都与
TextView
。
static let numberFormat: NumberFormatter = {
let numberFormatter = NumberFormatter()
numberFormatter.numberStyle = .none
numberFormatter.positivePrefix = "+"
numberFormatter.negativePrefix = "-"
return numberFormatter
}()
My attempted usage: but I am getting the error Instance method 'appendInterpolation(_:formatter:)' requires that 'Int' inherit from 'NSObject'
我尝试的用法:但我收到错误
Instance method 'appendInterpolation(_:formatter:)' requires that 'Int' inherit from 'NSObject'
Text("\(450, formatter: Self.numberFormat)")
Here is a simple way:这是一个简单的方法:
With this way, you would keep your @State
as clean as possible.通过这种方式,您将尽可能保持
@State
干净。 Also, the formatterFunction(number: Int)
is reusable now and accessible from everywhere in comparison to your way, which would not be reusable or accessible.此外,与您的方式相比,
formatterFunction(number: Int)
现在是可重用的,并且可以从任何地方访问,而您的方式是不可重用或可访问的。
extension Formatter {
static let number: NumberFormatter = {
let formatter = NumberFormatter()
formatter.numberStyle = .none
formatter.positivePrefix = "+"
formatter.negativePrefix = "-"
return formatter
}()
}
func formatterFunction(number: Int) -> String {
Formatter.number.string(for: number) ?? ""
}
struct ContentView: View {
@State var number: Int = 450
var body: some View {
Text(formatterFunction(number: number))
}
}
If you just want to add + and - to your Text, then use simply this function below:如果您只想在文本中添加 + 和 -,那么只需使用下面的 function:
func formatterFunction(number: Int) -> String {
if number > 0 {
return "+" + String(number)
}
else if number < 0 {
return "-" + String(abs(number))
}
else {
return String(number)
}
}
Swift needs to be told to cast the Int to an NSNumber for the formatter.需要告知 Swift 将 Int 转换为格式化程序的 NSNumber。
Text("\(450as NSNumber, formatter: Self.numberFormat)")
No other changes to your code necessary.无需对您的代码进行其他更改。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.