I am getting this error "InvalidOperationException was unhandled" when switching from Form6 to my Main Form with a Form change button. It does not happen every time. Sometimes I can change 5 times in a row and other times I can't change once without the error.
My Form6 is opened by clicking any selection button on Forms 1 through 4. This action also transfers the name of the selection to a BasicLabel on From6. I don't know if the error is happening because the original form is still open in the background when I leave Form6 or if something else is going on.
This is what I'm using for Forms1-4
Public Class Form1
Private Sub Form_VisibleChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.VisibleChanged
If components IsNot Nothing Then
Dim drv As AdvancedHMIDrivers.IComComponent
'*****************************
'* Search for comm components
'*****************************
For i As Integer = 0 To components.Components.Count - 1
If components.Components(i).GetType.GetInterface("AdvancedHMIDrivers.IComComponent") IsNot Nothing Then
drv = components.Components.Item(i)
'* Stop/Start polling based on form visibility
drv.DisableSubscriptions = Not Me.Visible
End If
Next
End If
End Sub
Private DrinkName As String
Private Sub LongIsland_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LongIsland.Click
DrinkName = "Long Island"
LoadForm6(DrinkName)
End Sub
Private Sub LongBeach_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LongBeach.Click
DrinkName = "Long Beach"
LoadForm6(DrinkName)
End Sub
Private Sub LoadForm6(ByVal DrinkName As String)
Dim oForm As New Form6
oForm.SetDrinkName = DrinkName
oForm.Selection.Text = DrinkName
oForm.ShowDialog()
Me.Close()
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
End Sub
End ClassI tried adding in the Me.Close() because the Form was staying open in the background but it doesn't seem to work.
My Form6 code
Public Class Form6
Private Sub Form_VisibleChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.VisibleChanged
If components IsNot Nothing Then
Dim drv As AdvancedHMIDrivers.IComComponent
'*****************************
'* Search for comm components
'*****************************
For i As Integer = 0 To components.Components.Count - 1
If components.Components(i).GetType.GetInterface("AdvancedHMIDrivers.IComComponent") IsNot Nothing Then
drv = components.Components.Item(i)
'* Stop/Start polling based on form visibility
drv.DisableSubscriptions = Not Me.Visible
End If
Next
End If
End Sub
Private DrinkName As String = ""
Public WriteOnly Property SetDrinkName As String
Set(ByVal value As String)
DrinkName = value
End Set
End Property
Private Sub Form6_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
End Sub
End Class
Any suggestions? I'm down to the wire on getting this project done on time.
