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:
Code: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
