My.Application.OpenForms Property

Gets a collection of all the application's open forms.

' Usage
Dim value As System.Windows.Forms.FormCollection = My.Application.OpenForms
' Declaration
Public ReadOnly Property OpenForms As System.Windows.Forms.FormCollection

Property Value

A FormCollection object that contains all of the application's open forms.

Remarks

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.

Tasks

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

To

See

Display the titles of all the application's open forms

How to: Access All Open Forms of an Application

Example

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.

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.

Requirements

Namespace:Microsoft.VisualBasic.ApplicationServices

Class:WindowsFormsApplicationBase

Assembly: Visual Basic Runtime Library (in Microsoft.VisualBasic.dll)

Availability by Project Type

Project type

Available

Windows Application

Yes

Class Library

No

Console Application

No

Windows Control Library

No

Web Control Library

No

Windows Service

No

Web Site

No

Permissions

The following permission may be necessary:

Permission

Description

UIPermission

Controls the permissions related to user interfaces and the clipboard. Associated enumeration: AllWindows.

For more information, see Code Access Security and Requesting Permissions.

See Also

Reference

My.Application Object

System.Windows.Forms.FormCollection

WindowsFormsApplicationBase.OpenForms

Application.OpenForms