swift - 如何将函数返回到标签 StringValue

Question

func GetTheTime() {
    let calendar = NSCalendar.current
    let date = Date()
    _ = Calendar.current

    let hour = calendar.component(.hour, from: date)
    let minutes = calendar.component(.minute, from: date)
    let seconds = calendar.component(.second, from: date)
    print("\(hour):\(minutes):\(seconds)")
    var theTime = "\(hour):\(minutes):\(seconds)"

如何调用它并让它返回并显示到 label.StringValue 中？

Answer 1

要返回某些内容，您可以添加一个箭头以及您想要返回的数据类型。就像这样:

func getTheTime() -> String {
    let calendar = NSCalendar.current
    let date = Date()
    _ = Calendar.current
    let hour = calendar.component(.hour, from: date)
    let minutes = calendar.component(.minute, from: date)
    let seconds = calendar.component(.second, from: date)
    return "\(hour):\(minutes):\(seconds)"
}

然后您可以像使用字符串一样使用 getTheTime() 函数，这样您就可以执行以下操作:

myLabel.text = getTheTime()

如果您希望它始终显示以秒为单位的更新时间，则必须调用一个定时函数，您可以在堆栈溢出上找到该函数的答案。