WindowsFormsApplicationBase.OpenForms Property

The My.Application.OpenForms property gets a collection of all the application's open forms. The behavior is identical to the Application.OpenForms property.

Note
The My.Application.OpenForms property returns all open forms, regardless of which thread opened them. You should check the InvokeRequired property of each form before accessing it; otherwise, it might throw an InvalidOperationException exception. For more information, see How to: Access All Open Forms of an Application (Visual Basic).

The following table lists examples of tasks involving the My.Application.OpenForms property.

Availability by Project Type

This example loops over the application's open forms, selects the ones directly accessible by the current thread, and displays their titles in a ListBox control. To access the open forms, see How to: Access All Open Forms of an Application (Visual Basic).

Private Sub GetOpenFormTitles()
    Dim formTitles As New Collection

    Try
        For Each f As Form In My.Application.OpenForms
            If Not f.InvokeRequired Then
                ' Can access the form directly.
                formTitles.Add(f.Text)
            End If
        Next
    Catch ex As Exception
        formTitles.Add("Error: " & ex.Message)
    End Try

    Form1.ListBox1.DataSource = formTitles
End Sub

This example requires that your Windows Forms application have a form named Form1 that contains a list box named ListBox1.

.NET Framework

.NET Framework Client Profile

• UIPermission  

  Controls the permissions that are related to user interfaces and the Clipboard. Associated enumeration: AllWindows.

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

Other Resources