模拟Windows风格的ListView缩略图自绘

ListView缩略图模式与WINDOWS一样的效果
procedure TForm1.ListView1AdvancedCustomDrawItem(Sender: TCustomListView;
  Item: TListItem; State: TCustomDrawState; Stage: TCustomDrawStage;
  var DefaultDraw: Boolean);
var
  NodeRect:TRect;
  NodeLabelRect:TRect;
  imageWidth,ImageHeight,RectWidth,RectHeight,i:Integer;
begin
  if Sender<>ListView1 then Exit;
  if ListView1.ViewStyle=vsIcon then
  with Sender.Canvas do begin
    DefaultDraw:=False;//禁止ListView的默认绘制
  
    if Item.Selected then begin
      Brush.Color :=clBlue;
      NodeLabelRect.Bottom:=NodeLabelRect.Top+(NodeLabelRect.Bottom-NodeLabelRect.Top)div 2;
    end else begin
      Brush.Color:=ListView1.Color;
    end;
    //自绘标题
    NodeLabelRect:=Item.DisplayRect(drLabel);
    TextRect(NodeLabelRect,NodeLabelRect.Left,NodeLabelRect.Top,Item.Caption);

    NodeRect := Item.DisplayRect(drIcon);
    imageWidth := (Sender as TListView).LargeImages.Width;
    ImageHeight := (Sender as TListView).LargeImages.Height;
    RectWidth := NodeRect.Right - NodeRect.Left;
    RectHeight := NodeRect.Bottom - NodeRect.Top;
    //计算一个使图像居中的rect坐标