Passing data from one form to another form's textboxes - vb.net

Question

I am trying to pass the selected nodes from a treeview to another form that is displayed in the text boxes.
this is my code in TreeView1_NodeMouseDoubleClick event
the code works fine when the data from the selected treeview is shown in the same form, but the problem is when I want to pass it to the other form 4 nothing is shown and the debug shows me that if it receives the values ​​but they are not reflected, maybe my code to refer to the other form is wrong I would like a support with this case.
Private Sub TreeView1_NodeMouseDoubleClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TreeNodeMouseClickEventArgs) Handles TreeView1.NodeMouseDoubleClick
Dim nodeKey As String = TryCast(e.Node.Tag, String)
Dim form4 As New Form4
' Dim nodetext As String = TryCast(e.Node.Tag, String)
'Dim nodeKey As String = DirectCast(e.Node.Tag, String)
If nodeKey IsNot Nothing AndAlso nodeKey.StartsWith("DIST") Then
'You have double clicked a district node
Dim IDDISTRITO As Integer = Integer.Parse(nodeKey.Substring(4))
form4.lblco.Text = IDDISTRITO
'Do something with the district id here
'...
form4.txtdis.Text = e.Node.Text
form4.txtpro.Text = e.Node.Parent.Text
form4.txtdepa.Text = e.Node.Parent.Parent.Text
End If
End Sub
so I call form 3 where is the treeview
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim for3 As New Form3
for3.Show()
End Sub

Answer 1

As you assumed, yes you are referencing the forms incorrectly. Please follow this technique. In form3 class, declare a public variable Public Dim form4 As New Form4.
Then modify the form3 calling procedure like this:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim for3 As New Form3
for3.form4 = Me
for3.Show()
End Sub
Now modify your existing code to this :
Private Sub TreeView1_NodeMouseDoubleClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TreeNodeMouseClickEventArgs) Handles TreeView1.NodeMouseDoubleClick
Dim nodeKey As String = TryCast(e.Node.Tag, String)
' Dim nodetext As String = TryCast(e.Node.Tag, String)
'Dim nodeKey As String = DirectCast(e.Node.Tag, String)
If nodeKey IsNot Nothing AndAlso nodeKey.StartsWith("DIST") Then
'You have double clicked a district node
Dim IDDISTRITO As Integer = Integer.Parse(nodeKey.Substring(4))
form4.lblco.Text = IDDISTRITO
'Do something with the district id here
'...
form4.txtdis.Text = e.Node.Text
form4.txtpro.Text = e.Node.Parent.Text
form4.txtdepa.Text = e.Node.Parent.Parent.Text
End If
End Sub
I have not tested the above code, but I believe you have got the idea.

Answer 2

Well I managed to solve it, the simplest thing was complicated, I publish the solution.
form 4 by calling 3
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim for3 As New Form3
AddOwnedForm(for3)
for3.ShowDialog()
End Sub
just add this code and voila
Dim form4 As Form4 = CType(Owner, Form4)