How to run multiple timer in a form? - vb.net

Question

I have a panel with 50 button and 1 label in my form
Private Sub flp_table_paint(sender As Object, e As PaintEventArgs) Handles flp_table.Paint
Dim i As Integer
For i = 1 To 50
Dim btn_tableNo As New Button
btn_tableNo.Width = 40
btn_tableNo.Height = 40
btn_tableNo.Text = i
AddHandler btn_tableNo.Click, AddressOf TableButtonClicked
Dim timer As New Timer
timer.Tag = i
Me.flp_table.Controls.Add(btn_tableNo)
Next
End Sub
What I try to do is, for every single button that i clicked they will start their own timer and show on the label.
Example:
11:00:00PM - Clicked on Button1 , lb_timer will show 1,2,3,4...
11:00:30PM - Clicked on Button2 , lb_timer will show 1,2,3,4...
11:00:45PM - Clicked on Button1 again, lb_timer will show 45,46,47,48...
11:00:50PM - Clicked on Button2 again, lb_timer will show 20,21,22,23...
Here is what i try so far, but fail...
Private Sub TableButtonClicked(ByVal sender As Object, ByVal e As EventArgs)
Dim currButton As Button = sender
selectedTable = currButton
For Each timer As Timer In Me.Controls
If timer.Tag = selectedTable.Text Then
timer.Start()
lb_timer.Text = timer.ToString
End If
Next
End Sub
I have no idea how to make it work, please help me...

Answer 1

Here asynchronous approach without Timer and one eventhandler for all buttons
' In constructor
AddHandler button1.Click, AddressOf Button_Click
AddHandler button2.Click, AddressOf Button_Click
AddHandler button3.Click, AddressOf Button_Click
' ... rest of buttons
' variable will keep name of the button which number is showing
Private _selectedButtonName As String
Private Async Sub Button_Click(sender As object, e As EventArgs)
Dim button As Button = DirectCast(sender, Button)
_selectedButtonName = button.Name
Dim isRunning As Boolean = (button.Tag IsNot Nothing)
If isRunning = True Then return
await StartCounterAsync(button)
End Sub
Private Async Function StartCounterAsync(Button button) As Task
button.Tag = new object()
Dim number As Integer = 0
While True
await Task.Delay(1000)
number += 1
If _selectedButtonName.Equals(button.Name)
lb_timer.Text = $"{button.Name}: {number}"
End If
End While
End Function
You can add CancellationToken in case you want reset counters.

Answer 2

Sadly the timer doesn't show elapsed time. An easier control to use for your purpose would be the StopWatch control. Its quite similar and will show a running time.
Dim StopWatchTest As New Stopwatch
StopWatchTest.Start()
Dim EllapsedTime As String = StopWatchTest.ElapsedMilliseconds / 1000
However since you want to continually update the label with the ellapsed time, you would need a timer to update the label at every tick.
Dim UpdateLabelTimer As New Timer()
UpdateLabelTimer.Interval = 1000 'How often to update your label (in milliseconds)
AddHandler UpdateLabelTimer.Tick, AddressOf Tick
UpdateLabelTimer.Start()
----------
Private Sub Tick()
lblLabel.text = StopWatchTest.ElapsedMilliseconds
End Sub