VB.Net Timer Pause/Stop

Question

please anyone help me on my problem on timer. I set my timer to 1minute. (60seconds). By clicking the start and pause button runs well but after click another button to resume the time it does not accurate on what time i pause. Example: I start my timer (1minute) and pause to 40seconds. After i resume, the time is not exactly on what my time pause. Instead of 40 seconds it starts in 30 like that depends on what time i click the resume button. It just like it continues in running even i stop the timer. Here is my code.

Private Sub Timer2_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer2.Tick

    If alarmTime < Date.Now Then
        ' Display the new time left 
        ' by updating the Time Left label.
        Timer2.Stop()
        MessageBox.Show("Times Up!.", "Thank you!")
        BtnBack.Enabled = True
        startButton.Enabled = False
        BtnSubmit.Enabled = False
        AnsA.Enabled = False
        AnsB.Enabled = False
        AnsC.Enabled = False
        AnsD.Enabled = False
        BtnNext.Enabled = False
        BtnPrev.Enabled = False
        BtnClose.Enabled = True
        Categoriess.lnkMathHS.Enabled = False
    Else
        Dim remainingtime As TimeSpan '= Me.alarmTime.Subtract(Date.Now)
        remainingtime = Me.alarmTime.Subtract(Date.Now)
        timeLabel.Text = String.Format("{0}:{1:d2}:{2:d2}", _
        remainingtime.Hours, _
        remainingtime.Minutes, _
        remainingtime.Seconds)
    End If

End Sub

Private Sub startButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles startButton.Click

    alarmTime = Date.Now.AddMinutes(TextBox1.Text)
    Timer2.Start()

End Sub


Private Sub resumeButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles resumeButton.Click

    Timer2.start()

End Sub

 Private Sub stopButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles stopButton.Click

    Timer2.stop()

End Sub

Joe Uhren Joe Uhren · Accepted Answer · 2015-01-26T06:17:50

The reason your timer seems to keep running while it is paused is because you are comparing the alartTime to the computer system time. Obviously the system time on a computer keeps changing every second and doesn't obey pauses. When you resume your timer it is still comparing to the current time which has inevitably changed since the pause.

To solve this issue I would store a copy of the current time when you press the start button and compare the alarm time to the saved start time which will no longer change:

Dim alarmTime As DateTime
Dim startTime As DateTime   ' New start time variable to save a copy of the current date/time when the start button is clicked

Private Sub Timer2_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer2.Tick
    Dim remainingtime As TimeSpan

    alarmTime = alarmTime.AddSeconds(-1)    ' subtract 1 second from the alarm time
    remainingtime = Me.alarmTime.Subtract(startTime)    ' get the amount of time between the saved start time and the current alarm time

    If alarmTime >= startTime Then
        ' There is still more time left on the alarm so we update the label with the subtracted time

        timeLabel.Text = String.Format("{0}:{1:d2}:{2:d2}", _
        remainingtime.Hours, _
        remainingtime.Minutes, _
        remainingtime.Seconds)
    End If

    If remainingtime.TotalSeconds = 0 Then
        ' The time has elapsed

        ' Display the new time left 
        ' by updating the Time Left label.
        Timer2.Stop()
        MessageBox.Show("Times Up!.", "Thank you!")
        BtnBack.Enabled = True
        startButton.Enabled = False
        BtnSubmit.Enabled = False
        AnsA.Enabled = False
        AnsB.Enabled = False
        AnsC.Enabled = False
        AnsD.Enabled = False
        BtnNext.Enabled = False
        BtnPrev.Enabled = False
        BtnClose.Enabled = True
        Categoriess.lnkMathHS.Enabled = False
    End If
End Sub

Private Sub startButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles startButton.Click

    Me.Timer2.Interval = 1000   ' Ensure that the timer is ticking once per second
    startTime = Date.Now    ' Save a copy of the current date/time
    alarmTime = Date.Now.AddMinutes(TextBox1.Text)
    Timer2.Start()

End Sub

Note: Only the Timer2_Tick and startButton_Click events need to be updated. You must also create the global startTime variable as well. Since you didn't show the code for how you created the alarmTime variable, I assumed it was a datetime variable that was global to your form. You can create the startTime variable the same way you created alarmTime.

VB.Net Timer Pause/Stop

1 Answers