Question

I’m trying to show multiple forms equal, first declare a variable of type Form, then set the variable a name, then display it but I can not have success.

It dont show any new window.

Dim from_var As New Form
from_var = inventory_stat_item

With from_var
    .MdiParent = main
    .StartPosition = FormStartPosition.CenterScreen
    .Show()
End With

UPDATE:
The variable from_var shall have the following forms names: (inventory_stat_item | inventory_edit_item | inventory_new_item)

Answer 1

You should be able to do what you want as long as you are creating and newing the Forms before hand. Something like this quick and dirty example.

Public Class Form1
    Dim inventory_stat_item As Form2 = New Form2
    Dim inventory_edit_item As Form3 = New Form3
    Dim inventory_new_item As Form4 = New Form4
    Public Sub New()

        ' This call is required by the designer.
        InitializeComponent()

        ' Add any initialization after the InitializeComponent() call.

        showForms(inventory_edit_item)
        showForms(inventory_new_item)
        showForms(inventory_stat_item)

    End Sub

    Private Sub showForms(from_var As Form)
        With from_var
            .MdiParent = Me
            .StartPosition = FormStartPosition.CenterScreen
            .Show()

        End With
    End Sub
End Class