倒计时不起作用（使用秒表类 + 调度器定时器）

Question

我正在初始化小时、分钟和秒

然后将其转换为总毫秒数。

然后我正在做的是从 Elapsed MilliSeconds 中减去 Total MilliSeconds

即elms = cms - e.Milliseconds

（计算的毫秒数 = 计算的毫秒数。- Stopwatch.elapsedMilliseconds）

然后将评估的毫秒转换回 HH:MM:SS:MS 格式。

但由于某些逻辑错误，它无法正常工作，这就是为什么我需要一些帮助。请帮帮我 这是我的代码：

        Dim dd As Integer = 0
        Dim mm As Integer = 0
        Dim hh As Integer = 0
        Dim ss As Integer = 0
        Dim ms As Integer = 0
        Dim cms As Long = 0
        Dim elms As Long = 0

    Dim stopwatch As System.Diagnostics.Stopwatch = New System.Diagnostics.Stopwatch
    Dim dt As DispatcherTimer = New DispatcherTimer

    Private Sub StartButton_Click(sender As Object, e As RoutedEventArgs) Handles StartButton.Click

                hh = Hours.Text * 60 * 60 * 1000
                mm = Minutes.Text * 60 * 1000
                ss = Seconds.Text * 1000
                cms = hh + mm + ss
                hh = mm = ss = 0
                Start()
    End Sub

    Private Sub Start()

                dt.Interval = New TimeSpan(0, 0, 0, 0, 10)
                AddHandler dt.Tick, AddressOf ontimertick
                stopwatch.Start()
                dt.Start()

            End If
    End Sub

    Private Sub ontimertick()


            Dim e As New TimeSpan
            e = stopwatch.Elapsed

                elms = cms - e.Milliseconds
                ss = ((elms Mod (1000 * 60 * 60)) Mod (1000 * 60)) \ 1000
                mm = (elms Mod (1000 * 60 * 60)) \ (1000 * 60)
                hh = elms \ (1000 * 60 * 60)
                elms = elms Mod 1000

                MicroSeconds.Text = elms.ToString("00")
                Seconds.Text = ss.ToString("00")
                Minutes.Text = mm.ToString("00")
                Hours.Text = hh.ToString("00")
    End Sub

Answer 1

错误在这里：

ss = ((elms Mod (1000 * 60 * 60)) Mod (1000 * 60)) \ 1000
mm = (elms Mod (1000 * 60 * 60)) \ (1000 * 60)
hh = elms \ (1000 * 60 * 60)
elms = elms Mod 1000

一定是：

ss = ((elms Mod (1000 * 60 * 60)) Mod (1000 * 60)) \ 1000
 elms=elms-(ss*1000)
mm = (elms Mod (1000 * 60 * 60)) \ (1000 * 60)
 elms=elms-(mm*1000)
hh = elms \ (1000 * 60 * 60)
 elms=elms-(hh*1000)
elms = elms Mod 1000

好吗？

Answer 2

你把事情复杂化了。您需要做的就是将总时间存储为TimeSpan 对象。然后，您可以从中减去StopWatch.Elapsed 时间，因为它也是TimeSpan。然后，计算产生的TimeSpan 对象将包含剩余时间。例如：

' Get the total desired time for count down
Dim total As New TimeSpan(Integer.Parse(Hours.Text), Integer.Parse(Minutes.Text), Integer.Parse(Seconds.Text))

' Later, get the time left and display on screen
Dim timeLeft As TimeSpan = total - stopwatch.Elapsed
Hours.Text = timeLeft.TotalHours
Minutes.Text = timeLeft.TotalMinutes
Seconds.Text = timeLeft.TotalSeconds

显然，像这样调用Integer.Parse 并不安全，因为文本框可能包含非数字值。您将需要添加代码来处理它。例如，如果您只想在输入无效时默认为零，您可以执行以下操作：

Dim totalHours As Integer
Dim totalMinutes As Integer
Dim TotalSeconds As Integer
Integer.TryParse(Hours.Text, totalHours)
Integer.TryParse(Minutes.Text, totalMinutes)
Integer.TryParse(Seconds.Text, totalSeconds)
Dim total As New TimeSpan(totalHours, totalMinutes, totalSeconds)

或者，如果您想显示验证错误消息，您可以执行以下操作：

Dim total As TimeSpan
Try
    total = New TimeSpan(Integer.Parse(Hours.Text), Integer.Parse(Minutes.Text), Integer.Parse(Seconds.Text))
Catch ex As FormatException
    MessageBox.Show("Entries must be numeric.")
End Try