[RESOLVED] 9 Timers

[dbasnett]

What is the most timers you have used in an application? I think the most I have ever used is 2.


In another forum this question was asked. "I have a Timer ... I have a situation where I want to run the code in the Tick event ONLY ONCE not on the interval i have the timer set too."

I responded with
Timer1_Tick(New Object, New System.EventArgs)

Which led to this

"The 'sender' object is VERY important when you have more than one Timer being handled by the Tick event procedure. This is because in a multi-timer tick event procedure, the only way your program knows which timer just fired is by querying the 'sender' object.

When you use code like this you are putting nothing into the 'sender' object, so that if you were ever going to query it a 'kaboom' is going to happen."

"...this 9 timer Tick event handler job done. Remember, all that is required is the correct timer name gets put into the ListBox." "The need for multi-timers to be handled by a single Tick event handler happens all the time. How would a real life programmer handle this? "


Oh, to test the "kaboom" theory I wrote this and ran it overnight successfully:

Public Class Form1

    Dim run As Boolean = False
    Dim pickIT As Integer = 0
    Dim lock As New Object

    Private Sub Form1_FormClosing(ByVal sender As Object, _
                                  ByVal e As System.Windows.Forms.FormClosingEventArgs) _
                                  Handles Me.FormClosing

        run = False
        Threading.Thread.Sleep(1000)

    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, _
                           ByVal e As System.EventArgs) Handles MyBase.Load

        Timer1.Start()
        Timer2.Start()
        Timer3.Start()
        Timer4.Start()
        Timer5.Start()
        Timer6.Start()
        Timer7.Start()
        Timer8.Start()
        Timer9.Start()

        'lets make it interesting by breaking all of ash2's rules
        'shouldn't be hard to "Kaboom" according to him

        For x As Integer = 0 To 499
            Dim t As New Threading.Thread(AddressOf PointlessForest)
            t.IsBackground = True
            t.Start()
        Next

    End Sub

    Private Sub PointlessForest()
        Do While Not run
            Threading.Thread.Sleep(100)
        Loop
        Do
            'a little variety
            Threading.Monitor.Enter(lock)
            If pickIT > Integer.MaxValue \ 2 Then pickIT = 0
            pickIT += 1
            If (pickIT And 1) = 0 Then 'if pickit is even then
                Threading.Monitor.Exit(lock)
                _TickTock(New TextBox, New System.EventArgs)
            Else
                Dim foo As String = "For oblio " & pickIT.ToString
                Threading.Monitor.Exit(lock)
                _TickTock(foo, New System.EventArgs)
            End If
            Threading.Thread.Sleep(10)
        Loop While run
    End Sub

    Private Sub _TickTock(ByVal sender As System.Object, _
                            ByVal e As System.EventArgs) _
                            Handles Timer1.Tick, Timer2.Tick, Timer3.Tick, _
                            Timer4.Tick, Timer5.Tick, Timer6.Tick, _
                            Timer7.Tick, Timer8.Tick, Timer9.Tick

        Dim t As System.Windows.Forms.Timer
        If TypeOf sender Is System.Windows.Forms.Timer Then
            t = DirectCast(sender, System.Windows.Forms.Timer)
            If ReferenceEquals(t, Timer1) Then
                Debug.WriteLine("T1")
            ElseIf ReferenceEquals(t, Timer2) Then
                Debug.WriteLine("T2")
            ElseIf ReferenceEquals(t, Timer3) Then
                Debug.WriteLine("T3")
            ElseIf ReferenceEquals(t, Timer4) Then
                Debug.WriteLine("T4")
            ElseIf ReferenceEquals(t, Timer5) Then
                Debug.WriteLine("T5")
            ElseIf ReferenceEquals(t, Timer6) Then
                Debug.WriteLine("T6")
            ElseIf ReferenceEquals(t, Timer7) Then
                Debug.WriteLine("T7")
            ElseIf ReferenceEquals(t, Timer8) Then
                Debug.WriteLine("T8")
            ElseIf ReferenceEquals(t, Timer9) Then
                Debug.WriteLine("T9")
            Else
                Stop
            End If
        Else
            Debug.WriteLine(sender.ToString) 'uncomment to test
        End If

        'I am waiting on an answer?
        'Debug.WriteLine(sender.name) 'this doesn't work
        'Debug.WriteLine(t.name) 'name' is not a member of 'System.Windows.Forms.Timer'.

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, _
                              ByVal e As System.EventArgs) Handles Button1.Click
        run = True

    End Sub
End Class