Question

Below is some code that I’m using to create objects with Visual Basic:

    For indexCounter As Integer = 1 To TotalParticipants Step 1

        participantClock = New Label
        participantClock.Size = New Size(100, 20)
        participantClock.Name = "participantClock" & indexCounter
        participantClock.Location = New Point(139, (5 + ((indexCounter - 1) * 26)))
        participantClock.BorderStyle = BorderStyle.Fixed3D
        participantClock.TextAlign = ContentAlignment.MiddleRight
        CenterPanel.Controls.Add(participantClock)

        participantStop = New Button
        participantStop.Size = New Size(58, 20)
        participantStop.Location = New Point(245, (5 + ((indexCounter - 1) * 26)))
        participantStop.BackColor = Color.Red
        participantStop.ForeColor = Color.White
        participantStop.Font = New Font(participantStop.Font, FontStyle.Bold)
        participantStop.Text = "Stop"
        CenterPanel.Controls.Add(participantStop)

        participantTimer = New Timer
        participantTimer.Start()
        participantTimer.Enabled = True
        participantTimer.Interval = 1

        participantStopwatch = New Stopwatch
        participantStopwatch.Start()
Next

I’m creating a label, a button, Timer, and Stopwatch. (Though I have sinking feeling I don’t need BOTH a timer and stopwatch since I’m counting time.)

What I would like to do, is create the label and set that label’s text to be the value from the stopwatch. The button that will be created will stop THAT stopwatch.

The problem that I’m having is that I cannot call the stopwatch by name since it wasn’t created yet and VB throws a hissy fit at me for it. (After all it wasn’t really declared.)

So the question becomes, how do you call the most recently dynamically created control and assign events using that control. If it’s not possible to do, I do not mind dumping the form and starting over creating 30 stopwatches instead (but I’d like to avoid that, if possible).

Thanks for any help.

Answer 1

I assume that you want the timer to update the label based on the value of the stopwatch. Is that right?

One thing that you might try that is a little hacky is this:
Define a storage class like so:

Public Class StopwatchStorage
    Public Property Stopwatch as Stopwatch
    Public Property Label as Label
    Public Property Timer as Timer
End Class

at the top of your form define a private list:

Private _storage as new List(Of StopwatchStorage)

at the end of your for loop do this

Dim storage As New StopwatchStorage()
storage.Label = participantClock
storage.Timer = participantTimer
storage.Stopwatch = participantStopwatch
_storage.Add(storage)
AddHandler participantTimer.Tick, AddressOf Timer_Tick

The above code would give you access to the three objects that you need in your tick function. You will have to loop through the _storage list to find the right “set” of objects but it should work:

Private Sub Timer_Tick(sender As Object, args As EventArgs)
    For Each storage As StopwatchStorage In _storage
        If storage.Timer Is sender Then
            storage.Label.Text = storage.Stopwatch.Elapsed
            Exit Sub
        End If
    Next
End Sub

I didn’t try to compile that code so I’m sure there are a few typos but I think that should give you an idea of how to refer to the object without needing to use the object’s name.