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Form.TopLevel Property

Gets or sets a value indicating whether to display the form as a top-level window.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

public bool TopLevel { get; set; }
/** @property */
public boolean get_TopLevel ()

/** @property */
public void set_TopLevel (boolean value)

public function get TopLevel () : boolean

public function set TopLevel (value : boolean)

Not applicable.

Property Value

true to display the form as a top-level window; otherwise, false. The default is true.

Exception typeCondition

Exception

A Multiple-document interface (MDI) parent form must be a top-level window.

A top-level form is a window that has no parent form, or whose parent form is the desktop window. Top-level windows are typically used as the main form in an application.

The following code example use the Modal property to determine if a form is displayed as a modal form. If it is not the FormBorderStyle and TopLevel properties are changed to make the form non-top-level form with a tool window border.

private void ShowMyNonModalForm()
{
    Form myForm = new Form();
    myForm.Text = "My Form";
    myForm.SetBounds(10,10,200,200);

    myForm.Show();
    // Determine if the form is modal.
    if(myForm.Modal == false)
    {
        // Change borderstyle and make it not a top level window.
        myForm.FormBorderStyle = FormBorderStyle.FixedToolWindow;
        myForm.TopLevel = false;
    }
}

private void ShowMyNonModalForm()
{
    Form myForm = new Form();
    myForm.set_Text("My Form");
    myForm.SetBounds(10, 10, 200, 200);
    myForm.Show();

    // Determine if the form is modal.
    if (myForm.get_Modal() == false) {
        // Change borderstyle and make it not a top level window.
        myForm.set_FormBorderStyle(get_FormBorderStyle().FixedToolWindow);
        myForm.set_TopLevel(false);
    }
} //ShowMyNonModalForm

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0
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