How to access parent form properties from a child form in vb.net-CodePudding

I have pretty much the same problem as described in this, but using VB.NET. There is a Form1 which is opened automatically as start window, so I cannot find the instance to use for accessing it. There is a Form2 opened from within Form1. I try to pass the instance of Form1 using keyword "Me":

Private Sub Button1_click(...) Handles Button1.Click
 Dim childform as new Form2(Me)
 childform.show()
End Sub

In Form2 I have:

Public Sub New(parentform As System.Windows.Forms.Form)
 InitializeComponents()
 MessageBox.Show(parentform.Button1.Text)
End Sub

Upon compiling I get the error: "Button1 is not a member of Form". So how to pass the Form1 instance correctly to Form2?

Also I want to change some properties of the Button1 of Form1 from Form2. Button1 is declared in a Private Sub, will I nevertheless be able to access it from Form2 if I pass the instance correctly? If not, can I declaring a sub in Form1, e.g.

Public Shared Sub ChangeText(newtext As Sting)
 Me.Button1.Text=newtext
End Sub

that will do the job?

CodePudding user response：

I'm not 100% sure about what you are trying to achieve, but, you can pass data between forms. So for example you can do something like:

Public Class Form1
   Private Sub Button1_click(...) Handles Button1.Click
      Dim newForm2 as New Form2()
      newForm2.stringText = ""
      If newForm2.ShowDialog() = DialogResult.OK Then
         Button1.Text = newForm2.stringText
      End If
   End Sub
End Class

And in Form2 you have

Public Class Form2
   Dim stringText as string

   Private Sub changeStringText()
      'your method to change your data
      Me.DialogResult = DialogResult.OK 'this will close form2
   End Sub
   
End Class

I hope this is what you need, if not let me know

CodePudding user response：

Thanks for your answer and comment. So I declared the wrong class for the parentform, means in Form2 it needs to be "parentform as Form1":

Public Sub New(parentform As Form1)
 InitializeComponents()
 MessageBox.Show(parentform.Button1.Text)
End Sub

and yes, I need to skip the "shared" in the ChangeText:

Public Sub ChangeText(newtext As Sting)
 Me.Button1.Text=newtext
End Sub

This way it worked for me.