DBGrid中顯示行號的終極解決方案（Delphi篇）

DBGrid中顯示行號的終極解決方案 
        昨天在大富翁論壇上見一貼子，求在DBGrid中顯示行號的方法，並稱此題為“曠世難題”，我一想，這樣的題目也叫曠世難題？於是自己就動手嚐試，結果發現原來並不簡單，確實是有點難度。後來又在網上搜索良久，也始終找不到一個很好的解決方案，有的也只是在瀏覽狀態下才能實現，而在Insert下卻不能實現，所有的行號都顯示為 -1。
        難道？delphi真的是無能為力的嗎？我不信，幾經試驗，終於讓我找到了解決方法，代碼如下：

//聲明全局變量i
 
procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
begin
  with DBGrid1.DataSource.DataSet do
  begin
    if DataCol = 0 then                           //設置在第一列
    begin
      if state<>dsInsert  then i:= recno;           //這句是關鍵。。。
      DBGrid1.Canvas.TextRect(Rect, Rect.Left + 2, Rect.Top + 2, IntToStr(i));
      inc(i);                  //將i加1
    end;
  end;
end;
 
procedure TForm1.DataSource1StateChange(Sender: TObject);
begin                                            //狀態改變時將i置為1
  i:=1;
end;
 
        問題完美解決了，代碼也很簡單，只是加了一個中間變量 i 。
        到目前為為止，網上還未見到此種解決方案，如有雷同，純屬巧合。  
                                                                                      
以上方法後來證明還是有點問題，修正如下：
var
  Form1: TForm1;
  i:integer;
  bflag,bflag2:boolean;
 
implementation
 
{$R *.dfm}
 
procedure TForm1.Button1Click(Sender: TObject);
begin
  adoquery1.Open;
end;
 
procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
  var
    rect1:TRect;
    sValue :string;
    ss:boolean;
begin
  if DataCol = 0 then                           //設置在第一列
  begin
    if DBGrid1.DataSource.DataSet.state<>dsInsert  then
      i:= DBGrid1.DataSource.DataSet.recno;
 
    Rect1 := Rect;
    with dbgrid1 do
    begin
      Canvas.Brush.Color := clBtnFace;
      sValue := IntToStr(i);
      Canvas.FillRect(Rect1);
      Canvas.Pen.Width := 1;
      Canvas.Pen.Color := clWhite;
      Canvas.MoveTo(Rect1.Left, Rect1.Bottom);
      Canvas.LineTo(Rect1.Left, Rect1.Top);
      Canvas.LineTo(Rect1.right, Rect1.Top);
      Canvas.Pen.Color := clBtnShadow;
      Canvas.LineTo(Rect1.right, Rect1.Bottom - 1);
      Canvas.LineTo(Rect1.Left, Rect1.Bottom - 1);
      Rect1.Top := Rect1.Top +1;
      if State = [gdSelected, gdFocused] then
      begin
        if bflag=true then
        begin
          sValue:=inttostr(datasource.DataSet.RecordCount +1);
          i:=datasource.DataSet.RecordCount +1;
            ss:=true;
        end;
      Canvas.Font.Color := clred;
      end
      else
      begin
        Canvas.Font.Color := clgreen;
      end;
      DrawText(Canvas.Handle, PChar(sValue), Length(sValue), Rect1, DT_CENTER);
    end;
    if i<=dbgrid1.DataSource.DataSet.RecordCount then
    begin
      inc(i);
    end
    else
    begin
    if (ss<>true) then
      i:=dbgrid1.DataSource.DataSet.RecordCount+3 -TDrawGrid(DBgrid1).RowCount ;
    end;
  end
  else bflag2:=false;
end;
 
procedure TForm1.DataSource1StateChange(Sender: TObject);
begin
  if dbgrid1.DataSource.DataSet.State <>dsbrowse then
  begin
    i:=dbgrid1.DataSource.DataSet.RecordCount+3 -TDrawGrid(DBgrid1).RowCount ;
    bflag := true;
  end
  else
    bflag:=false;
end;
 
procedure TForm1.DBGrid1ColEnter(Sender: TObject);
begin
 if (bflag=true)and (dbgrid1.SelectedField.FieldNo <>1) then
 begin
  i:=dbgrid1.DataSource.DataSet.RecordCount+3 -TDrawGrid(DBgrid1).RowCount;
  dbgrid1.Refresh;
 end;
end;
 
procedure TForm1.DBGrid1ColExit(Sender: TObject);
begin
  if (bflag=true)and (dbgrid1.SelectedField.FieldNo =1) then
 begin
  i:=dbgrid1.DataSource.DataSet.RecordCount+1;
  dbgrid1.Refresh;
 end;
end;
 
end.