How do I access a property from a dialog form before it gets closed, VB.NET winforms

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Hi,
Hope all of you are well and settling into 2018 :)

I'll break this down into some simple terms as the project is quite complicated to describe, so here's the basics.

Form1 creates a new instance of Form2 and shows it as showdialog - I cannot access the List declaration from Form2, into Form1.

I cannot have global declarations or variables - explained further, below.

What I have tried:

I have two forms, both created in the designer.
Form1 creates a new instance/copy of Form 2 via

Dim NewForm As New Form2
                NewForm.ShowDialog()

I am using showdialog but I am happy to use just show but that gives me a new set of problems, which is to find out from Form2, that calling Form, that is creating a new instance/copy of Form2, has been closed.

The project will contain many more forms i.e. Form3, Form4, Form5....Form20, all creating a new copy of Form2 and need to access "that copy of List(of String)" from Form2, so a global declaration of the List(of String) is not possible.

Those calling forms, to Form2 - may also be created via a new form command, from other forms. So keeping track via variables of whether that form has been closed, is no good to me.

On Form2, I have some data that I am storing in a

List(Of String)

In Form2, I have declared at the top of the class:

Dim _Keywords As New List(Of String)

   Friend ReadOnly Property Keywords() As List(Of String)
       Get
           Return _Keywords
       End Get

   End Property

I need to access (from Form1 ,3,4,5,6....20) the List(Of String) on Form2 before it gets disposed/closed/set to nothing and not any sooner.

At the moment I do this in Form1 after the showdialog:

 Dim Kwords As List(Of String) = GlobalFind.Keywords
NewFrm.Dispose
NewFrm=Nothing

in Form1, Kwords list its always empty, I get a count=0 when I look. Hope that makes sense and Thank you for giving me your time (and hopefully a solution I have overlooked).

Posted 5-Jan-18 20:36pm

Member 12561559

Updated 5-Jan-18 21:15pm

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Graeme_Grant · Accepted Answer · 2018-01-05T21:15:00

Expose a property on Form2, then get the results in Form1:

Form2

VB

Public Class Form2

    Private mResults As List(Of String)
    Public Property Results() As List(Of String)
        Get
            Return mResults
        End Get
        Set(ByVal value As List(Of String))
            mResults = value
        End Set
    End Property

    Private Sub butSave_Click(sender As Object, e As EventArgs) Handles butSave.Click

        ' set results here
        Results = New List(Of String) From {"111", "222", "333"}

        Close()

    End Sub

End Class

Form1

VB

Public Class Form1

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        Dim NewForm As New Form2
        NewForm.ShowDialog()

        Dim results As List(Of String) = NewForm.Results

    End Sub

End Class