Passing data through form with showdialog but without closing event - vb.net

Question

I have a first form (form_notice_hashtag) called like this:
Public Sub afficher_hashtag(hashtag As String, plateforme_hashtag As String)
Dim form_notice_hashtag_1 As New form_notice_hashtag
form_notice_hashtag_1.StartPosition = FormStartPosition.CenterScreen
form_notice_hashtag_1.Show()
End Sub
In form_notice_hashtag_1, i have a button calling a 2nd form (form_recherche_thesaurus) like this:
Private Sub hashtag_thesaurus_search_button_Click(sender As Object, e As EventArgs) Handles hashtag_thesaurus_search_button.Click
Dim form_recherche_thesaurus_1 As New form_recherche_thesaurus With {
.StartPosition = FormStartPosition.Manual,
.Location = New Point(Me.Left + Me.Width, Me.Top)
}
form_recherche_thesaurus_1.ShowDialog(Me)
End Sub
In form_recherche_thesaurus, i have a datagridview listing some words. The user can select one word, then by clicking a button in form_recherche_thesaurus, the word which will be added to a textbox in form_notice_hashtag
Private Sub thesaurus_ok_button_Click(sender As Object, e As EventArgs) Handles thesaurus_ok_button.Click
Dim list_terms_array As String()
Select Case Owner.Name.ToString
Case "form_notice_hashtag"
list_terms_array = Split(Remove_Duplicates_From_Strings_With_SemiColon(form_notice_hashtag.hashtag_descripteurs_txtbox.Text & ";" & selected_term), ";")
form_notice_hashtag.hashtag_descripteurs_txtbox.Text = (String.Join(";", list_terms_array.Where(Function(s) Not String.IsNullOrEmpty(s))))
End Select
End Sub
I used a select because this mechanism would be used in the same way with other forms than form_notice_hashtag.
Problem: the textbox in form_notice_hashtag is not filled with the selected keywords. I guess it's because of the way form_notice_hashtag is called.
I can't use the solution as explained here Send values from one form to another form because i understood (maybe badly) that this solution works only if the 2nd form (form_recherche_thesaurus in my case) is closed (i.e closing was the trigger) which i don't want.
How can I proceed?

Answer 1

Thanks to jmcilhinney and this page of his blog, here is the solution that allows to transfer several data from a called form (form_recherche_thesaurus) to a calling form (form_notice_hashtag) without closing the called form .
Public Class form_notice_hashtag
Private WithEvents form_recherche_thesaurus_1 As form_recherche_thesaurus
Private selected_thesaurus_term As String
Private Sub form_recherche_thesaurus_1_TextBoxTextChanged(sender As Object, e As EventArgs) Handles form_recherche_thesaurus_1.TextBoxTextChanged
Dim list_terms_array As String() = Split(Remove_Duplicates_From_Strings_With_SemiColon(Me.hashtag_descripteurs_txtbox.Text & ";" & form_recherche_thesaurus_1.selected_term), ";")
Me.hashtag_descripteurs_txtbox.Text = (String.Join(";", list_terms_array.Where(Function(s) Not String.IsNullOrEmpty(s))))
End Sub
Private Sub hashtag_thesaurus_search_button_Click(sender As Object, e As EventArgs) Handles hashtag_thesaurus_search_button.Click
Dim form_recherche_thesaurus_1 As New form_recherche_thesaurus With {
.StartPosition = FormStartPosition.Manual,
.Location = New Point(Me.Left + Me.Width, Me.Top)
}
If Me.form_recherche_thesaurus_1 Is Nothing OrElse Me.form_recherche_thesaurus_1.IsDisposed Then
Me.form_recherche_thesaurus_1 = New form_recherche_thesaurus With {
.StartPosition = FormStartPosition.Manual,
.Location = New Point(Me.Left + Me.Width, Me.Top)
}
Me.form_recherche_thesaurus_1.Show()
End If
Me.form_recherche_thesaurus_1.Activate()
End Sub
End Class
Public Class form_recherche_thesaurus
Public Event TextBoxTextChanged As EventHandler
Private term_thesaurus As String
Public Property selected_term() As String
Get
Return term_thesaurus
End Get
Set(ByVal value As String)
term_thesaurus = value
End Set
End Property
Private Sub thesaurus_ok_button_Click(sender As Object, e As EventArgs) Handles thesaurus_ok_button.Click
Dim list_terms_array As String()
Me.selected_term = Me.thesaurus_search_results_datagrid.Item(0, Me.thesaurus_search_results_datagrid.CurrentRow.Index).Value
Me.DialogResult = DialogResult.OK
RaiseEvent TextBoxTextChanged(Me, EventArgs.Empty)
End Sub