【 tulaoshi.com - 编程语言 】
                             
                            procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
    DataCol: Integer; Column: TColumn; State: TGridDrawState);
  var
    s:String;
  begin
    TDBGrid(Sender).DefaultDrawColumnCell(Rect,DataCol,Column,State);
    s:=Column.Field.DisplayText;
    if (Column.FieldName='FAX') and (Length(s)10) then
    begin
      with TDBGrid(Sender).Canvas do
      begin
        Pen.Color :=clRed;
        Arc(Rect.Left,Rect.Top,Rect.Right,Rect.Bottom,Rect.Left,Rect.Top,Rect.Left,Rect.Top);
      end;
    end;
  end;
  直接画圆弧就可以了,后面的这种方法只是提供一种参考:
  procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
    DataCol: Integer; Column: TColumn; State: TGridDrawState);
  const
    Flags:array [TAlignment] of DWORD=(DT_LEFT,DT_RIGHT,DT_CENTER);
  var
    s:String;
    R:TRect;
  begin
    TDBGrid(Sender).DefaultDrawColumnCell(Rect,DataCol,Column,State);
    s:=Column.Field.DisplayText;
    r:=Rect;
    if (Column.FieldName='FAX') and (Length(s)10) then
    begin
      with TDBGrid(Sender).Canvas do
      begin
        Pen.Color :=clRed;
        RoundRect(Rect.Left,Rect.Top,Rect.Right,Rect.Bottom,Rect.Left,Rect.Top);
        DrawText(Handle,pchar(s),length(s),R,Flags[Column.Alignment] or DT_VCENTER);
      end;
    end;
  end;  
  bytetype,用于判断某个 Char 是单个字母,还是双字节的前一位或后一位。
  mbSingleByte 单字母
  mbLeadByte 双字节第一位
  mbTrailByte 双字节第二位  
  ExtractStrings,分割字符串