Question

我有一些代码可以获得今天和另一个时间字符串之间的时间差异。

使用NSTimer.scheduledTimerWithTimeInterval每秒刷新一次显示。

除非计时器达到0，否则一切正常。0显示两次。

示例：

3,2,1,0,0,-1,-2

以下是我在游乐场完成的代码：

   //: Playground - Time Countdown
import UIKit
import XCPlayground
XCPSetExecutionShouldContinueIndefinitely()

class MyClass {

    var totalSecondsText = ""

    init(classSecondsText: String){
        totalSecondsText = classSecondsText
    }

    @objc func ontimer(timer:NSTimer!){

        let total = determineTimeDifference(totalSecondsText)

                let (hour,min,sec) = secondsConverter(total)

                if hour >= 1 {
                    if min >= 1 {
                        NSLog(String(hour)+"h "+String(min)+"m")
                    }else {
                        NSLog(String(hour)+"h")
                    }
                }else{
                    if min >= 1{
                        NSLog(String(min)+"m "+String(sec)+"s")
                    } else if min > -1 {
                        NSLog(String(sec)+"s")
                    } else if min <= -1 {
                        NSLog(String(min)+"m")
                    }
                }
    }

    func determineTimeDifference(timeInputed: String) -> Int {

         let dateFormat = NSDateFormatter()
         dateFormat.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
         let finalDate = dateFormat.dateFromString(raceTime)
         let differenceTimeInSeconds =  (finalDate?.timeIntervalSinceNow)!

    return differenceInSeconds

   }

    func secondsConverter (seconds : Int) -> (Int  , Int, Int){
        return (seconds / 3600, (seconds % 3600) / 60, (seconds % 3600) % 60)
    }

}

// Add +1 minute on time to test.
var dateString = "2016-08-31T6:49:00Z"

NSTimer.scheduledTimerWithTimeInterval(1, target: MyClass(classSecondsText: dateString), selector: #selector(MyClass.ontimer(_:)), userInfo: nil, repeats: true)

对于出了什么问题有什么想法吗？

更新

正如所承诺的，这是针对此问题的错误修复：

    func determineTimeDifference(timeInputed: String) -> Int {

             let dateFormat = NSDateFormatter()
             dateFormat.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
             let finalDate = dateFormat.dateFromString(raceTime)?.timeIntervalSince1970
             let dateNow = NSDate().timeIntervalSince1970
             let differenceTimeInSeconds = Int(finalDate) -  Int(dateNow)

     return differenceInSeconds
}

Answer 1

您的代码提供良好，条件正确。看起来Data.components没有正确处理计数差异。它可以由秒组件组成。

如果在此刻之前计算，当前时间和最终时间相等，（达到0,0），结果会出现错误-1 。

当我使用其他打印更新您的代码时，会显示：

CURRENT date: 2016-08-31 13:10:57 +0000 - FINAL date: 2016-08-31 13:11:00 +0000
-->> diff by DateComponents: 2s (BAD)
CURRENT unix: 1472649057.28685 - FINAL unix: 1472649060.0
--->>> Diff in UNIX:  -3.0s (counted as Rounded CURRENT UNIX - FINAL UNIX)
2s 

CURRENT date: 2016-08-31 13:10:58 +0000 - FINAL date: 2016-08-31 13:11:00 +0000
-->> diff by DateComponents: 1s (BAD)
CURRENT unix: 1472649058.28734 - FINAL unix: 1472649060.0
--->>> Diff in UNIX:  -2.0s (counted as Rounded CURRENT UNIX - FINAL UNIX)
1s 

CURRENT date: 2016-08-31 13:10:59 +0000 - FINAL date: 2016-08-31 13:11:00 +0000
-->> diff by DateComponents: 0s (BAD)
CURRENT unix: 1472649059.28731 - FINAL unix: 1472649060.0
--->>> Diff in UNIX:  -1.0s (counted as Rounded CURRENT UNIX - FINAL UNIX)
0s 

CURRENT date: 2016-08-31 13:11:00 +0000 - FINAL date: 2016-08-31 13:11:00 +0000
-->> diff by DateComponents: 0s (OK)
CURRENT unix: 1472649060.28731 - FINAL unix: 1472649060.0
--->>> Diff in UNIX:  0.0s (counted as Rounded CURRENT UNIX - FINAL UNIX)
0s 

CURRENT date: 2016-08-31 13:11:01 +0000 - FINAL date: 2016-08-31 13:11:00 +0000
-->> diff by DateComponents: -1s (OK)
CURRENT unix: 1472649061.28731 - FINAL unix: 1472649060.0
--->>> Diff in UNIX:  1.0s (counted as Rounded CURRENT UNIX - FINAL UNIX)
-1s 

CURRENT date: 2016-08-31 13:11:02 +0000 - FINAL date: 2016-08-31 13:11:00 +0000
-->> diff by DateComponents: -2s (OK)
CURRENT unix: 1472649062.28729 - FINAL unix: 1472649060.0
--->>> Diff in UNIX:  2.0s (counted as Rounded CURRENT UNIX - FINAL UNIX)
-2s

因此，如果使用舍入的unix时间之间的差值进行计数，则结果是正确的。

结论：错误有时会出现在等式之前，有时会出现。这取决于该脚本的发布时间。如果按数据组件计数以错误开始，则在0,0后清除。如果计数以正确的结果开始，则结果开始带来错误结果。这就是为什么零出现两次 - 在结果改变其精确状态的那一刻。

NSTimer倒计时产生0两次

1 个答案: