问题来源: http://www.cnblogs.com/del/archive/2009/12/24/1631729.html#2097194
GDI+ 接口: http://www.cnblogs.com/del/archive/2009/12/11/1621790.html
示例代码:
uses GdiPlus;
procedure TForm1.StringGrid1DrawCell(Sender: TObject; ACol, ARow: Integer; Rect: TRect;
State: TGridDrawState);
var
Graphics: IGPGraphics;
Pen: IGPPen;
begin
//获取绘图表面
Graphics := TGPGraphics.Create(TWinControl(Sender).Handle);
//设置绘图质量以消除锯齿
Graphics.SmoothingMode := SmoothingModeHighQuality;
//画笔
Pen := TGPPen.Create(TGPColor.Red, 1);
//随便画了两条线
Graphics.DrawLine(Pen, Rect.Left, Rect.Top, Rect.Right, Rect.Bottom);
Graphics.DrawLine(Pen, Rect.Right, Rect.Top, Rect.Left, Rect.Bottom);
end;