xcode - 无法将 nsnumber 类型的值分配给值类型字符串

Question

我正在使用数字格式化程序将值数字从 JSON 更改为带逗号的数字(例如 500000 到 500,000)。我想我已经记下了，但我收到一条错误消息:

cannot assign a value of type nsnumber to a value type string

if let supply = json["supply"] as? NSNumber{
    var numberFormatter = NSNumberFormatter()
    numberFormatter.numberStyle = NSNumberFormatterStyle.DecimalStyle
    numberFormatter.stringFromNumber(supply)!
    totalXRP.text = supply

}

Answer 1

您必须将 numberFormatter.stringFromNumber 的结果分配给您的文本字段:

if let supply = json["supply"] as? NSNumber{
    var numberFormatter = NSNumberFormatter()
    numberFormatter.numberStyle = NSNumberFormatterStyle.DecimalStyle
    if let result = numberFormatter.stringFromNumber(supply) {
        totalXRP.text = result
    }
}