TCustomStatusBar.Canvas Property

Provides runtime access to the status bar's drawing surface.

Pascal

property Canvas: TCanvas;

C++

__property TCanvas Canvas;

Description

The read-only Canvas property provides access to the status bar's drawing surface that you can use when implementing a handler for the OnDrawPanel event.

C++ Examples:

Copy Code

/*
The following code is the OnDrawPanel event handler of a
status bar.  It draws each panel of the status bar, adding
text and icons stored in ImageList1. The image list contains
as many icons as there are header sections.  This example
requires a populated image list and a statusbar with several
panels added to the Panels property.  Select each panel and
set the Style property to psOwnerDraw.
*/
void __fastcall TForm1::StatusBar1DrawPanel(TStatusBar *StatusBar,
        TStatusPanel *Panel, const TRect &Rect)
{
  TCanvas *canvas = StatusBar->Canvas;
  canvas->Brush->Color = clRed;
  canvas->FillRect(Rect);
  canvas->Font->Color = clYellow;
  ImageList1->Draw(canvas,Rect.Left,Rect.Top, Panel->Index, true);
  canvas->TextOut(Rect.left + 30, Rect.top + 2, "Panel" + IntToStr(Panel->Index));
}

Copy Code

/*
The following code uses ClientRect to find and draw a line
from the top left to the bottom right of the current
control.  Select a TControl in the ListBox list.  This
example assumes that the current object is a descendent of
TControl and has a public Canvas property.
*/
{
  TPoint APoint = Point(X, Y);
  int Index = ListBox1->ItemAtPos(APoint, True);
  TStatusBar *myStatusBar;
  TClass ClassRef = ListBox1->Items->Objects[Index]->ClassType();
  if (String(ClassRef->ClassName()) == "TStatusBar")
  {
    myStatusBar = dynamic_cast<TStatusBar *>(ListBox1->Items->Objects[Index]);
    // make sure we are using the TControls canvas and not the from's!
    myStatusBar->Canvas->MoveTo(myStatusBar->ClientRect.Left, myStatusBar->ClientRect.Top);
    myStatusBar->Canvas->LineTo(myStatusBar->ClientRect.Right, myStatusBar->ClientRect.Bottom);
    myStatusBar = NULL;
  }
}

Delphi Examples:

Copy Code

{
The following code is the OnDrawPanel event handler of a
status bar.  It draws each panel of the status bar, adding
text and icons stored in ImageList1. The image list contains
as many icons as there are header sections.  This example
requires a populated image list and a statusbar with several
panels added to the Panels property.  Select each panel and
set the Style property to psOwnerDraw.
}
procedure TForm1.StatusBar1DrawPanel(StatusBar: TStatusBar;
  Panel: TStatusPanel; const Rect: TRect);
begin
with StatusBar1.Canvas do
  begin
    Brush.Color := clRed;
    FillRect(Rect);
    Font.Color := clYellow;
    ImageList1.Draw(StatusBar1.Canvas,Rect.Left,Rect.Top,Panel.Index);
    TextOut(Rect.left + 30, Rect.top + 2, 'Panel' + IntToStr(Panel.Index));
  end;
end;

Copy Code

{
The following code uses ClientRect to find and draw a line
from the top left to the bottom right of the current
control.  Select a TControl in the ListBox list.  This
example assumes that the current object is a descendent of
TControl and has a public Canvas property.
}
  if (ListBox1.Items.Objects[Index] is TStatusBar) then
  begin
    myStatusBar:= (ListBox1.Items.Objects[Index] as TStatusBar);
    with myStatusBar.ClientRect do
    begin // make sure we are using the TControl's canvas and not the form's!
      myStatusBar.Canvas.MoveTo(Left, Top);
      myStatusBar.Canvas.LineTo(Right, Bottom);
    end;
  myStatusBar:= nil;
  end;