自己画,帮助里面的例子
procedure TCustomDrawForm.TVCustomDraw(Sender: TCustomTreeView; const ARect: TRect; var DefaultDraw: Boolean);
begin
//This event should be used to draw any background colors or images.
//ARect represents the entire client area of the TreeView.
//Use the TreeView's canvas to do the drawing.
//Note that drawing a background bitmap is not really supported by CustomDraw,
//so scrolling can get messy. Best to subclass the TreeView and handle scrolling
//messages.
with TV.Canvas do
begin
if None1.Checked then //no picture
begin
Brush.Color := BkgColorDialog.Color;
Brush.Style := FBrushStyle;
FillRect(ARect);
endelse
if Tile1.Checked then //tile bitmap
begin
Brush.Bitmap := Image1.Picture.Bitmap;
FillRect(ARect);
endelse //Stretch across the canvas.
StretchDraw(ARect, Image1.Picture.Bitmap);
end;
DefaultDraw := FDefaultDraw;
//setting DefaultDraw to false here prevents all calls to OnCustomDrawItem.
end;