Handling form in multiple forms created -Addressing the sender form

Hi,

I am new to vb.net.I have three form.
The first one is MDIparent form (Mainform) which will created unlimited MDIchild form of (Mpfform).Mpfform contain Data Grid View.
Each Mpfform can create only one (Dmfform -non MDI).
Dmfform contain one "Start" button.

My problem is, how can i address the specific Mpfform created by Mainform or
Dmfform created from specific Mpfform?

Ive tried using my code below with no success. Please help me.

1) code in Mainform : to create Mpfform

Public mpf(50) As Mpfform()
Public num As Integer = 0
 
Private Sub NewMenuItem_File_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles NewMenuItem_File.Click
 
        num += 1
        mpf(num) = New Mpfform()
 
'creating Mpfform

        mpf(num).Text = "ModbusPoll:" & CStr(num)
        mpf(num).Name = "ModbusPollFormFull" & num

'creating Dmfform
        mpf(num).dmf.Text = "Display Mode:" & CStr(num)
        mpf(num).dmf.Name = "Display Mode:" & num
 
'showing only Mpfform
        mpf(num).TopLevel = False
        mpf(num).BringToFront()
        mpf(num).Show()
  
 
End Sub

2) code in Mpfform - Showing Dmfform

Public dmf As New Dmfform

Private Sub DataDisplayModeMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DataDisplayModeMenuItem.Click
 
        dmf.Show()
        
End Sub

3)code in Dmfform - addressing problem

Private Sub Start_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Start.Click
        
        If Mainform.mpf(Mainform.num).Datagridview.RowCount <> Nothing Then
        
            Me.mytimer3.Interval = 1000
            Me.mytimer3.Start()
        Else
            MsgBox("Definition of the modbus properties is currently not available." & vbNewLine & "Please define the properties in the Measurement window : Communication >> Modbus Properties")

        End If
       
End Sub

How can i address the correct DGV of Mpfform to this code?

"Mainform.mpf(Mainform.num).Datagridview.RowCount" ?

Tags: Visual Basic