Form.TopLevel Property

Reference

Definition

Namespace:: System.Windows.Forms

Assembly:: System.Windows.Forms.dll

Source:: Form.cs

Source:: Form.cs

Source:: Form.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

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

public:
 property bool TopLevel { bool get(); void set(bool value); };

[System.ComponentModel.Browsable(false)]
public bool TopLevel { get; set; }

[<System.ComponentModel.Browsable(false)>]
member this.TopLevel : bool with get, set

Public Property TopLevel As Boolean

Property Value

Boolean

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

Attributes: BrowsableAttribute

Exceptions

Exception

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

Examples

The following 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 = gcnew Form;
      myForm->Text = "My Form";
      myForm->SetBounds( 10, 10, 200, 200 );
      myForm->Show();

      // Determine if the form is modal.
      if ( !myForm->Modal )
      {
         // 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.Text = "My Form";
    myForm.SetBounds(10,10,200,200);

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

Private Sub ShowMyNonModalForm()
    Dim myForm As New Form()
    myForm.Text = "My Form"
    myForm.SetBounds(10, 10, 200, 200)

    myForm.Show()
    ' Determine if the form is modal.
    If myForm.Modal = False Then
        ' Change borderstyle and make it not a top level window.
        myForm.FormBorderStyle = FormBorderStyle.FixedToolWindow
        myForm.TopLevel = False
    End If
End Sub

Remarks

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.

Applies to

Partilhar via