让cxGrid像Excel那样高亮显示选区的行号列标

　　Developer Express的cxGrid控件是一个相当有特色的数据栅格组件，支持自动分组、卡片式显示、和像Excel那样的过滤功能等。不过它在多选区时的显示方式却不太友善，对于我这样还有点追求的人来说肯定是不会满足的了，于是通过它的OnDrawColumnHeader事件和OnDrawIndicatorCell事件把它变成像Excel那样以高亮显示行号列标。一切以图片说话，如下图：

PS：我平时是用来显示数据的，没有考虑编辑状态；为了说明效果，cxGrid使用DBTableView并设成允许多选和选区方式（在OptionsView里有设）。

OnDrawColumnHeader事件源码如下：
procedure TfrmAccount.cxtvMasterCustomDrawColumnHeader(
  Sender: TcxGridTableView; ACanvas: TcxCanvas;
  AViewInfo: TcxGridColumnHeaderViewInfo; var ADone: Boolean);
var
    AButtonState: TcxButtonState;
    ARect: TRect;
begin
    if AViewInfo.Column.Selected then begin
        AButtonState := cxbsHot;
        ARect := AViewInfo.Bounds;
        Sender.LookAndFeelPainter.DrawHeader(ACanvas, ARect, AViewInfo.TextAreaBounds
            , [], cxBordersAll, AButtonState, AViewInfo.Column.HeaderAlignmentHorz
            , AViewInfo.Column.HeaderAlignmentVert, False, False
            , AViewInfo.Column.Caption, ACanvas.Font, Sender.Styles.Selection.TextColor
            , Sender.Styles.Selection.Color);
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        ARect.Left := ARect.Right - 19;
        ARect.Right := ARect.Right - 1;
        InflateRect(ARect, -1, -3);
        if AViewInfo.Column.Options.Filtering then begin
            Sender.LookAndFeelPainter.DrawFilterDropDownButton(ACanvas, ARect
                , cxbsNormal, AViewInfo.Column.Filtered);
            OffsetRect(ARect, -16, 0);
        end;
        if AViewInfo.Column.SortIndex <> -1 then
            Sender.LookAndFeelPainter.DrawSortingMark(ACanvas, ARect
                , AViewInfo.Column.SortOrder=soAscending);
        ADone := true;
    end;
end;

OnDrawIndicatorCell事件源码如下：
procedure TfrmAccount.cxtvMasterCustomDrawIndicatorCell(
  Sender: TcxGridTableView; ACanvas: TcxCanvas;
  AViewInfo: TcxCustomGridIndicatorItemViewInfo; var ADone: Boolean);
var
    AButtonState: TcxButtonState;
    clFont, clBrush: TColor;
begin
    if not (AViewInfo is TcxGridIndicatorRowItemViewInfo) then Exit;

    if TcxGridIndicatorRowItemViewInfo(AViewInfo).GridRecord.Selected then begin
        AButtonState := cxbsHot;
        if Sender.LookAndFeelPainter.LookAndFeelStyle = lfsOffice11 then begin
            clFont := ACanvas.Font.Color;
            clBrush := ACanvas.Brush.Color;
        end else begin
            clFont := Sender.Styles.Selection.TextColor;
            clBrush := Sender.Styles.Selection.Color;
        end;
    end else begin
        AButtonState := cxbsNormal;
        clFont := ACanvas.Font.Color;
        clBrush := ACanvas.Brush.Color;
    end;
    Sender.LookAndFeelPainter.DrawHeader(ACanvas, AViewInfo.ContentBounds,
        AViewInfo.ContentBounds, [], [bLeft, bRight, bBottom], AButtonState, taCenter
        , vaCenter, False, False, IntToStr(TcxGridIndicatorRowItemViewInfo(AViewInfo).GridRecord.Index + 1)
        , ACanvas.Font, clFont, clBrush);
    ADone := True;
end;