TControl.Visible Property

Determines whether the component appears onscreen.

Pascal

property Visible: Boolean;

C++

__property Boolean Visible;

Description

Use the Visible property to control the visibility of the control at runtime. If Visible is true, the control appears. If Visible is false, the control is not visible.

Calling the Show method sets the control's Visible property to true. Calling the Hide method sets it to false.

C++ Examples:

Copy Code

/*
This examples requires a TPageControl and a TCheckBox.  The
form OnCreate event handler populates each sheet with an
edit control placed somewhere on the client area of the
sheet.  Unchecking the checkbox will cause the client area
(not the tab area) of the Tab Control to become invisible.
*/
void __fastcall TForm1::PageControl1Change(TObject *Sender)
{
  CheckBox1->Checked = PageControl1->ActivePage->Visible;
}

void __fastcall TForm1::CheckBox1Click(TObject *Sender)
{
  PageControl1->ActivePage->Visible = CheckBox1->Checked;
}

void __fastcall TForm1::FormCreate(TObject *Sender)
{
  for (int i = 0; i < 10; i++)
  {
    TTabSheet *pPage = new TTabSheet(this);
    pPage->PageControl = PageControl1;
    pPage->Caption = AnsiString("Page") + IntToStr(i);
    TEdit *pEdit = new TEdit(this);
    pEdit->Parent = pPage;
    pEdit->Left = random(pPage->ClientWidth - pEdit->Width);
    pEdit->Top = random(pPage->ClientHeight - pEdit->Height);
  }
  PageControl1Change(Sender);
}

Delphi Examples:

Copy Code

{
This examples requires a TPageControl and a TCheckBox.  The
form OnCreate event handler populates each sheet with an
edit control placed somewhere on the client area of the
sheet.  Unchecking the checkbox will cause the client area
(not the tab area) of the Tab Control to become invisible.
}
procedure TForm1.CheckBox1Click(Sender: TObject);
begin
  PageControl1.ActivePage.Visible := CheckBox1.Checked;
end;

procedure TForm1.PageControl1Change(Sender: TObject);
begin
  CheckBox1.Checked := PageControl1.ActivePage.Visible;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  i: Integer;
begin
  for i := 0 to 9 do
    with TTabSheet.Create(Self) do
    begin
      PageControl := PageControl1;
      Caption := 'TabSheet' + IntToStr(i);
      with TEdit.Create(Self) do
      begin
        Parent := PageControl1.Pages[i];
        Left := Random(PageControl1.ActivePage.ClientWidth - Width);
        Top := Random(PageControl1.ActivePage.ClientHeight - Height);
      end;
    end;
    PageControl1Change(Sender);
end;