How to Trigger button click from another form VB Net - vb.net

Question

I have three forms in total and i want to trigger one of the button on form 3 to be triggered automatically when form 1 loaded
Form 1
Public Class frmIOMain
' In This Form load I want to trigger the above mentioned button
Private Sub IOMain_Load(sender As Object, e As System.EventArgs) Handles Me.Load
' I want to Trigger the Above mentioned button here when my form is loaded
' But it is not working for me
frmUpdateDueDates.cmdUpdate_Click(Nothing, Nothing)
End Sub
End Class
Form 2
Public Class TestEquipmentManagement
Public EquipementTable As New DataTable("EquipmentTable")
Public EquiTypeSelection As String
Public EquiManufacturerSelection As String
Public EquiList_PK As New List(Of Integer)
Dim targetEquipmentList As New List(Of Model.equipment)
Private equipDB As Model.Entities = Nothing
Public Shared viewManager As ViewManager
Private equipment As New List(Of Model.equipment)
'Dim WithEvents excNewPFM As New VBACom
Public EquipCalTable As New DataTable("EquipCalTable")
Public Sub New()
Dim todayplusoneyear As Date
todayplusoneyear = Date.Today
todayplusoneyear = todayplusoneyear.AddYears(1)
'Assign current db
equipDB = frmIOMain.db
End Sub
End Class
Form 3
Public Class frmUpdateDueDates
Private EquipmentUpdates As UpdateCalibrationsViewModel
Private _success As Boolean = False
Public Sub New(db As Entities)
' Dieser Aufruf ist für den Designer erforderlich.
InitializeComponent()
EquipmentUpdates = New UpdateCalibrationsViewModel(db, New CAQ23(), False)
'Add Handlers
AddHandler EquipmentUpdates.OnProgressChanged, AddressOf progressChangedHandler
AddHandler EquipmentUpdates.OnInfotextChanged, AddressOf infoTextChangedHandler
prgUpdates.Maximum = EquipmentUpdates.intProgressMax
End Sub
Public Sub cmdUpdate_Click(sender As Object, e As EventArgs) Handles cmdUpdate.Click
cmdUpdate.Enabled = False
_success = EquipmentUpdates.startUpdating()
cmdCancel.Text = "Close"
End Sub
End Class
I want "cmdUpdate_Click" Button which is on form 3 to be triggered when my form 1 is loaded
Can Anyone tell me how i can do that?

Answer 1

Firstly, create an instance of the form, instead of using its default form instance. Calling a click handler across forms isn't a good idea. The handler may use the arguments sender As Object, e As EventArgs and from outside of the containing class, you can't assume you know that. Better practice would be to create a method which performs the click within the form, such as
Public Class frmUpdateDueDates
Public Sub cmdUpdateClick()
cmdUpdate.PerformClick()
End Sub
Private Sub cmdUpdate_Click(sender As Object, e As EventArgs) Handles cmdUpdate.Click
cmdUpdate.Enabled = False
_success = EquipmentUpdates.startUpdating()
cmdCancel.Text = "Close"
End Sub
End Class
Public Class frmIOMain
Private myFrmUpdateDueDates As frmUpdateDueDates
Private Sub IOMain_Load(sender As Object, e As System.EventArgs) Handles Me.Load
myFrmUpdateDueDates = New FrmUpdateDueDates()
myFrmUpdateDueDates.Show()
'myFrmUpdateDueDates.cmdUpdate_Click(Nothing, Nothing)
myFrmUpdateDueDates.cmdUpdateClick()
End Sub
End Class
And you can change the access modifier of the click handler back to Private
Even better would be to put the work into a different method which the click handler calls. Then the other form doesn't even need to know the button exists. Such as
Public Class frmUpdateDueDates
Public Sub DoUpdating()
cmdUpdate.Enabled = False
_success = EquipmentUpdates.startUpdating()
cmdCancel.Text = "Close"
End Sub
Private Sub cmdUpdate_Click(sender As Object, e As EventArgs) Handles cmdUpdate.Click
DoUpdating()
End Sub
End Class
Public Class frmIOMain
Private myFrmUpdateDueDates As frmUpdateDueDates
Private Sub IOMain_Load(sender As Object, e As System.EventArgs) Handles Me.Load
myFrmUpdateDueDates = New FrmUpdateDueDates()
myFrmUpdateDueDates.Show()
'myFrmUpdateDueDates.cmdUpdate_Click(Nothing, Nothing)
myFrmUpdateDueDates.DoUpdating()
End Sub
End Class