Application.OpenForms Property (System.Windows.Forms)

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OpenForms Property

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This page is specific to

Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

Application..::.OpenForms Property

Gets a collection of open forms owned by the application.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)

Syntax

Visual Basic (Declaration)

Public Shared ReadOnly Property OpenForms As FormCollection

Visual Basic (Usage)

Dim value As FormCollection

value = Application.OpenForms

public static FormCollection OpenForms { get; }

Visual C++

public:
static property FormCollection^ OpenForms {
    FormCollection^ get ();
}

JScript

public static function get OpenForms () : FormCollection

Property Value

Type: System.Windows.Forms..::.FormCollection
A FormCollection containing all the currently open forms owned by this application.

Remarks

The OpenForms property represents a read-only collection of forms owned by the application. This collection can be searched by index position or by the Name of the Form.

.NET Framework Security

UIPermission
Caller must have permission to access all windows, as defined by the AllWindows value of the UIPermissionWindow enumeration.

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0

Reference

Application Class

Application Members

System.Windows.Forms Namespace

Exit

FormCollection

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Possible Bug Associated with Application.OpenForms

Rudedog2 | Edit | Show History

There is a nasty bug in the implementation of Application.OpenForms, you should avoid relying on it. This code shows the bug at work:

public partial class Form1 : Form {
public Form1() {
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e) {
this.ShowInTaskbar = !this.ShowInTaskbar;
MessageBox.Show("Number of open forms: " + Application.OpenForms.Count);
}
}

This info is courtesy of

Hans Passant.