[RESOLVED] a tale of two timers

Hi folks.

I have a form with a label. I want the form to display a message every 5 seconds, and the message to display for 700ms before closing. So I used timer1 with an interval of 5000ms, and timer2 with an interval of 700ms. But the message seems to be displaying every 5 seconds(what I want), but is displayed for 5 seconds(what I don't want). I want the message to display only for 700ms. Where is the problem in the code? Thanks in advance.

Code:

---

Public Class Form1

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Timer1.Start()
    End Sub

    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        Timer2.Start()
    End Sub

    Private Sub Timer2_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer2.Tick
        If Me.Visible = True Then
            Me.Visible = False
        Else
            Me.Visible = True
            Me.Label1.Text = "Test Message"
        End If
        Timer2.Stop()
    End Sub
End Class

---

Try using a single timer running often enough to do both jobs of turning on and turning off the message.

Retain the last time turned on so you can manage the on/off.

Thanks for your reply. I will give your suggestion a go, but before that, could you explain why my program displays the message for 5 seconds, instead of 7/10 of a second? I am looking at my code, and I just can't figure out this strange behaviour. Thank you.

It is because you have explicitly tied the speed to Timer1.

Each time Timer1 fires, you start Timer2. When Timer2 fires, you do the work and disable Timer2 - and then have to wait until Timer1 starts it again.

The simplest solution is to make two changes (add a line, and move one):

Code:

---

Public Class Form1

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Timer1.Start()
    End Sub

    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        Timer2.Start()
        Timer1.Stop()
    End Sub

    Private Sub Timer2_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer2.Tick
        If Me.Visible = True Then
            Me.Visible = False
            Timer2.Stop()
        Else
            Me.Visible = True
            Me.Label1.Text = "Test Message"
        End If
    End Sub
End Class

---

szlamany's suggestion is more elegant and self-contained, but takes a bit more code... this is one way it could be done (with just Timer1):

Code:

---

Public Class Form1

    Private TimerStartedAt as Date

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        TimerStartedAt = Now()
        Timer1.Interval = 100
        Timer1.Start()
    End Sub

    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        Select Case (Now - TimerStartedAt).TotalMilliseconds
        Case 5000 To 5700
            If Not Me.Visible Then
                Me.Visible = True
                Me.Label1.Text = "Test Message"
            End If
        Case > 5700
            Me.Visible = False
            Timer1.Stop()
        End Select
    End Sub
End Class

---