给DBGrid动态赋值后，如何用程序指定某行某列为当前焦点？(100分)

让第3行第2列(“用户名称”列)获得焦点：
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, Grids, DBGrids, DB, ADODB;

type
TForm1 = class(TForm)
ADOTable1: TADOTable;
DataSource1: TDataSource;
DBGrid1: TDBGrid;
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
ADOTable1.RecNo := 3;
ADOTable1.FieldByName(‘用户名称‘).FocusControl;
end;

end.

窗口2打开时焦点定位在DBGrid1的3行2列：
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, Grids, DBGrids, DB, ADODB;

type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

uses
unit2;

procedure TForm1.Button1Click(Sender: TObject);
begin
Form2.ShowModal;
end;

end.

************************************************

unit Unit2;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, DB, ADODB, Grids, DBGrids;

type
TForm2 = class(TForm)
DataSource1: TDataSource;
DBGrid1: TDBGrid;
ADOTable1: TADOTable;
procedure FormShow(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form2: TForm2;

implementation

{$R *.dfm}

procedure TForm2.FormShow(Sender: TObject);
begin
ADOTable1.RecNo := 3;
ADOTable1.Fields[1].FocusControl;
end;

end.

还是改不好。我这个是MDI程序，MainForm中 Form1.ShowModal，Form1中Form2.ShowModal，Form1中有DBGrid，Form2是修改窗口，Form2修改之后
Form1.DBGrid1.Fields[3].FocusControl;出错。不用Form2直接在Form1中也不好用。
真是不好改。

你在Form2上做了什么操作后Form1.DBGrid1.Fields[3].FocusControl出的错？把代码贴上来看看比较好找出问题。

MainForm中：
procedure TMainForm.Button1Click(Sender: TObject);
begin
Form1.ShowModal;
end;

Form1中：
procedure TForm1.FormShow(Sender: TObject);
begin

try
if DataModule1.ADOConnection1.Connected then
begin
sql2 := ‘select XuHao as 序号,zhengshuhao as 证书号,kuanhao as 款号,‘ +
‘xiaojia as 销价,rukuliang as 入库量,zhiquanhao as 指圈号,‘ +
‘shouhuoriqi as 收货日期,xiaoshouriqi as 销售日期,fanghuodanwei‘ +
‘ as 放货单位,nid as ID from KuCunInfo order by xuhao‘;

DataModule1.ADOQuery1.Close;
DataModule1.ADOQuery1.SQL.Text := sql2;
DataModule1.ADOQuery1.ExecSQL ;
DataModule1.ADOQuery1.Active := true;
end;

finally
end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
{修改KuCunInfo中的数据}

try
Form1.DBGrid1.Fields[3].FocusControl;
finally
end;
end;

这样就出错了，不用在Form2中修改。

哈哈，我弄出来了。在大富翁上搜索的。
Form1.DBGrid1.SelectedIndex := 4;
Form1.DBGrid1.SetFocus;
这样就行了。
谢谢你！

procedure TForm1.Button1Click(Sender: TObject);
begin
{修改KuCunInfo中的数据}
//修改完库存信息后，由于Form1中的数据还是旧的，所以需要在这里更新一下Form1中
//的数据，即：重新打开一次DBGrid1对应的数据集控件(DataModule1.ADOQuery1)，然后 
//再执行FocusControl
try
Form1.DBGrid1.Fields[3].FocusControl;
finally
end;
end;

另外以下代码：
DataModule1.ADOQuery1.Close;
DataModule1.ADOQuery1.SQL.Text := sql2;
DataModule1.ADOQuery1.ExecSQL ;
DataModule1.ADOQuery1.Active := true;
建议这样写：
DataModule1.ADOQuery1.Close;
DataModule1.ADOQuery1.SQl.Clear;
DataModule1.ADOQuery1.SQL.Add(sql2);
DataModule1.ADOQuery1.Open;
ADOQuery1控件，如果其SQL为select语句使用Open，如果是Insert、update、delete等不需要返回值的SQL用ExecSQL 。