EInvalidOperation----->Cannot focus a disabled or invisible window?????????????

Question

你可能在FormCreate里设置控件的焦点了吧，在OnShow里设置
另外就是不能设置焦点到Enabled为false的控件上

Answer 1

也不能把焦点设到 Visible为False的控件上。

Answer 2

多谢楼上两位关注,但
1.我没有直接使用setfocus{可能是运行的时候,系统需要吧};
2.产生此异常的代码行是table3.filtered:=true;
3.Delphi 5 Developer's Guide上对EInvalidOperation异常的解释为:
 当试图对一个没有"父"组件进行操作而这人操作又需要有窗口句柄时将触发这个异常.如下而的 代码:
 Var b:TBitBtn;
 begin
  b:TBitBtn.Create(Self);
  b.SetFocus;{这行将导致异常}
 end;
请继续关注!:):):)
 

Answer 3

那你就赋一个parent;
b.Parent := Form1;就ok了

Answer 4

唉！LOOK
原来是这样的!
我的表字段里设了一个必填项.{Required Field}
当我使用table1.filter过滤时,会出现空记录的情况,也就是Table1.RecordCount=0,但实际上在DbGrid1显示时,好像会自动Append一条空记录,从而导致记录录入错误,同时也引出一个问题，有没有办法让dbGrid1不要有那条空记录?{不知道这样分析对不对?}
不过说实在的，我刚从php转到delphi，我的代码实在是烂，特在此公布出来让有趣的朋友多提些意见!谢谢啦.
(这是一个售房管理程序)
MainFrm  Code as below:
------------------------------------
unit main;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  Menus, ImgList, ComCtrls, ToolWin, ExtCtrls, Grids, Buttons, DBGrids, Db,
  DBTables, StdCtrls, Mask, ShellAPI, DBCtrls;type
  Tmainfrm = class(TForm)
    ImageList1: TImageList;
    CoolBar1: TCoolBar;
    ToolBar1: TToolBar;
    ToolButton1: TToolButton;
    MainMenu1: TMainMenu;
    S1: TMenuItem;
    E1: TMenuItem;
    A1: TMenuItem;
    D1: TMenuItem;
    V1: TMenuItem;
    C1: TMenuItem;
    P1: TMenuItem;
    H1: TMenuItem;
    ToolButton2: TToolButton;
    ToolButton3: TToolButton;
    ToolButton4: TToolButton;
    ToolButton5: TToolButton;
    ToolButton6: TToolButton;
    ToolButton7: TToolButton;
    ToolButton8: TToolButton;
    ToolButton9: TToolButton;
    ToolButton10: TToolButton;
    X1: TMenuItem;
    TreeView1: TTreeView;
    StatusBar1: TStatusBar;
    PopupMenu1: TPopupMenu;
    A2: TMenuItem;
    D2: TMenuItem;
    C3: TMenuItem;
    N1: TMenuItem;
    DataSource1: TDataSource;
    Table1: TTable;
    Table2: TTable;
    DataSource2: TDataSource;
    N2: TMenuItem;
    N3: TMenuItem;
    Splitter2: TSplitter;
    Bevel1: TBevel;
    R1: TMenuItem;
    Shape2: TShape;
    V2: TMenuItem;
    N4: TMenuItem;
    S2: TMenuItem;
    N5: TMenuItem;
    N6: TMenuItem;
    N7: TMenuItem;
    L1: TMenuItem;
    C4: TMenuItem;
    DataSource3: TDataSource;
    Table3: TTable;
    QReportPop: TPopupMenu;
    R2: TMenuItem;
    B1: TMenuItem;
    N8: TMenuItem;
    Panel2: TPanel;
    SpeedButton1: TSpeedButton;
    Image1: TImage;
    Shape1: TShape;
    N9: TMenuItem;
    A3: TMenuItem;
    D3: TMenuItem;
    C5: TMenuItem;
    A4: TMenuItem;
    D4: TMenuItem;
    C6: TMenuItem;
    PageControl1: TPageControl;
    TabSheet1: TTabSheet;
    TabSheet2: TTabSheet;
    DBGrid1: TDBGrid;
    cardPop: TPopupMenu;
    V3: TMenuItem;
    V4: TMenuItem;
    E2: TMenuItem;
    N10: TMenuItem;
    N11: TMenuItem;
    N12: TMenuItem;
    N13: TMenuItem;
    L2: TMenuItem;
    C2: TMenuItem;
    Label16: TLabel;
    Splitter1: TSplitter;
    H2: TMenuItem;
    N14: TMenuItem;
    N15: TMenuItem;
    F1: TMenuItem;
    T1: TMenuItem;
    E3: TMenuItem;
    N16: TMenuItem;
    N21: TMenuItem;
    N31: TMenuItem;
    N17: TMenuItem;
    N18: TMenuItem;
    A5: TMenuItem;
    N19: TMenuItem;
    P2: TMenuItem;
    I1: TMenuItem;
    T2: TMenuItem;
    N20: TMenuItem;
    S3: TMenuItem;
    K1: TMenuItem;
    N22: TMenuItem;
    SIMTELA1: TMenuItem;
    N23: TMenuItem;
    D5: TMenuItem;
    E4: TMenuItem;
    ToolButton11: TToolButton;
    ToolButton12: TToolButton;
    Panel1: TPanel;
    Label1: TLabel;
    Bevel2: TBevel;
    Label27: TLabel;
    GroupBox1: TGroupBox;
    Label6: TLabel;
    Label7: TLabel;
    Label2: TLabel;
    Bevel3: TBevel;
    Label18: TLabel;
    Bevel5: TBevel;
    Label19: TLabel;
    Label20: TLabel;
    Label21: TLabel;
    Bevel6: TBevel;
    Label22: TLabel;
    Label23: TLabel;
    Label10: TLabel;
    Bevel4: TBevel;
    Label11: TLabel;
    Label24: TLabel;
    AreaRoom: TDBEdit;
    AreaTerrace: TDBEdit;
    AreaOther: TDBEdit;
    TotalArea: TDBEdit;
    total_fund: TDBEdit;
    GroupBox4: TGroupBox;
    Label12: TLabel;
    Label13: TLabel;
    Label14: TLabel;
    Label15: TLabel;
    DBEdit3: TDBEdit;
    DBEdit4: TDBEdit;
    DBEdit5: TDBEdit;
    DBEdit6: TDBEdit;
    GroupBox2: TGroupBox;
    Label3: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    Label8: TLabel;
    Label9: TLabel;
    ClientName: TDBEdit;
    identity_id: TDBEdit;
    Tel: TDBEdit;
    MobilePhone: TDBEdit;
    address: TDBEdit;
    GroupBox5: TGroupBox;
    Label26: TLabel;
    Label25: TLabel;
    Label17: TLabel;
    Label28: TLabel;
    Label30: TLabel;
    DBEdit7: TDBEdit;
    DBEdit8: TDBEdit;
    DBEdit9: TDBEdit;
    DBEdit10: TDBEdit;
    DBEdit11: TDBEdit;
    N24: TMenuItem;
    S4: TMenuItem;
    Label29: TLabel;
    Label31: TLabel;
    Label32: TLabel;
    Label33: TLabel;
    DateTimePicker1: TDateTimePicker;
    DateTimePicker2: TDateTimePicker;
    DateTimePicker3: TDateTimePicker;
    DateTimePicker4: TDateTimePicker;
    UnitPriceRoom: TDBComboBox;
    UnitPriceTerrace: TDBComboBox;
    UnitPriceOther: TDBComboBox;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Label34: TLabel;
    DBEdit1: TDBEdit;
    Shape3: TShape;
    procedure X1Click(Sender: TObject);
    procedure A2Click(Sender: TObject);
    procedure D2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure C3Click(Sender: TObject);
    procedure PopupMenu1Popup(Sender: TObject);
    procedure C4Click(Sender: TObject);
    procedure N6Click(Sender: TObject);
    procedure L1Click(Sender: TObject);
    procedure B1Click(Sender: TObject);
    procedure R2Click(Sender: TObject);
    procedure ToolButton5Click(Sender: TObject);
    procedure ToolButton6Click(Sender: TObject);
    procedure ToolButton7Click(Sender: TObject);
    procedure ToolButton8Click(Sender: TObject);
    procedure ToolButton2Click(Sender: TObject);
    procedure N4Click(Sender: TObject);
    procedure N9Click(Sender: TObject);
    procedure S2Click(Sender: TObject);
    procedure ToolButton1Click(Sender: TObject);
    procedure A3Click(Sender: TObject);
    function fList(selText,selTextfather:string):string;
    procedure PageControl1Change(Sender: TObject);
    procedure V3Click(Sender: TObject);
    procedure V4Click(Sender: TObject);
    procedure TreeView1Change(Sender: TObject; Node: TTreeNode);
    procedure SIMTELA1Click(Sender: TObject);
    procedure DBGrid1DblClick(Sender: TObject);
    procedure QReportPopPopup(Sender: TObject);
    procedure ToolButton11Click(Sender: TObject);
    procedure SpeedButton1Click(Sender: TObject);
    procedure ScrollBar1Change(Sender: TObject);
    procedure S4Click(Sender: TObject);
    procedure DBGrid1CellClick(Column: TColumn);
    procedure Table3AfterScroll(DataSet: TDataSet);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
    procedure Table3PostError(DataSet: TDataSet; E: EDatabaseError;
      var Action: TDataAction);
  private
    { Private declarations }
  public
    { Public declarations }  end;var
  mainfrm: Tmainfrm;implementationuses edit, house_info, card_report, qreport, splash, setCenter;
{$R *.DFM}procedure Tmainfrm.X1Click(Sender: TObject);
begin
close;
end;procedure Tmainfrm.A2Click(Sender: TObject);
var myname,type_id,t1,t2,father:string;
    catnode:tTreenode;
  begin
   case TreeView1.Selected.ImageIndex of
    0:begin
      t1:='添加新地块';
      t2:='请输入新添的地块名称:';
      end;
    1:begin
      t1:='添加新楼幢';
      t2:='请输入新添的楼幢名称:';
      end;
    2:begin
      t1:='添加新楼层';
      t2:='请输入新添的楼层名称:';
      end;
    3:begin
      t1:='添加新房间';
      t2:='请输入新添的房间名称:';
      end;
    4:begin
      saleEditFrm.show;
      exit;
      end;
     end;
  myname:=inputBox(t1,t2,'');
  if myname<>'' then
  begin
   table1.filter:='';
   table1.filtered:=true;
   if table1.Locate('name',myname,[]) and ((TreeView1.Selected.ImageIndex=0) or (TreeView1.Selected.ImageIndex=1)) then
   begin
    ShowMessage('对不起，已经存在'''+myname+''',请另取名称!');
    exit;
   end;
   if treeView1.selected.ImageIndex<>0 then
   begin
    if treeView1.selected.ImageIndex=3 then
     begin
     table1.first;
     table1.locate('name',treeview1.Selected.Parent.Text,[]);
     father:=table1.fieldByName('id').Text;
     table1.first;
     table1.locate('name;father',varArrayof([treeView1.Selected.Text,father]),[]);
     end
    else
    table1.locate('name',treeView1.Selected.Text,[]);
    father:=table1.fieldByName('id').Text;
    type_id:=table1.fieldByName('type_id').Text;
   end
   else begin
   father:='0';
   type_id:='0';
   end;
  if table1.canModify then
  begin
  table1.Append;
  table1.fieldbyName('name').value:=myname;
  table1.fieldByName('father').value:=father;
  table1.fieldByName('type_id').value:=strtoint(type_id);
  table1.post;
  end;
  catNode:=TreeView1.Items.AddChild(TreeView1.Selected,myname);
  catNode.ImageIndex:=TreeView1.Selected.ImageIndex+1;
  catNode.selectedIndex:=5;
  end;
end;procedure Tmainfrm.D2Click(Sender: TObject);
begin
  if MessageDlg('确定要删除 '+treeView1.selected.text+' 吗?',mtInformation,[mbOK,mbCancel],0)=mrOk then
  begin
  table1.filter:='';
  table1.filtered:=true;
    if table1.locate('name',treeView1.selected.text,[]) then
    begin
    table1.delete;
    treeView1.Items.Delete(treeView1.Selected);
    end
    else showMessage('数据有误,不能正常删除!');
   end;
end;procedure Tmainfrm.FormCreate(Sender: TObject);
var
  catnode,child,child1:ttreenode;
  id,father:string;
begin
  treeview1.items.clear;
  catnode:=treeview1.Items.AddFirst(nil,'所有楼幢名单');
  catnode.ImageIndex:=0;
  catnode.Selectedindex:=0;
  table1.filter:='';
  table1.filtered:=true;
  table1.filter:='father=''0''';
  table1.filtered:=true;
  if table1.Active=false then table1.active:=true;
  table1.First;
  while not table1.Eof do
  begin
   id:=table1.fields[0].asString;
    child:=treeview1.Items.AddChild(treeview1.items.GetFirstNode,table1.Fields[1].Text);
    child.ImageIndex:=1;
    child.Selectedindex:=5;
    father:=table1.Fields[0].text;
    table2.filter:='';
    table2.filtered:=true;
    table2.filter:='father='+id;
    table2.Filtered:=true;
    if table2.Active=false then table2.active:=true;
    table2.first;
    while not table2.eof do
    begin
    child1:=treeview1.Items.addchild(child,table2.fields[1].text);
    child1.ImageIndex:=2;
    child1.Selectedindex:=5;
    table2.Next;
    end;
  table1.Next;
  end;
//TreeView1.AutoExpand:=true;
  //table2.free;
end;
function Tmainfrm.fList(selText,selTextfather:string):string;
var  father:string;child:tTreeNode;imgidx:smallint;
begin
  statusBar1.Panels.Items[0].Text:=selText;
  table1.filter:='';
  table1.filtered:=true;
if treeView1.Selected.ImageIndex=3 then
 begin
 Table1.locate('name',selTextFather,[]);
 father:=Table1.FieldByName('id').Text;
 Table1.locate('name;father',varArrayof([selText,father]),[]);
 end
else if treeView1.Selected.ImageIndex=4 then
 begin
 result:='3';
 exit;
 end
else Table1.locate('name',selText,[]);
  result:=table1.fieldbyname('type_id').AsString;
 if not (TreeView1.Selected.HasChildren) then
 begin
  father:=Table1.FieldByName('id').Text;
  table1.Filter:='father='+father;
  table1.Filtered:=true;
  if (table1.RecordCount<>0) then
  begin
   table1.first;
   if TreeView1.Selected.ImageIndex=3 then
   imgidx:=4
   else
   imgidx:=3;
   while not table1.eof do
   begin
    child:=treeview1.Items.AddChild(TreeView1.Selected,table1.Fields[1].Text);
    child.ImageIndex:=imgidx;
    child.Selectedindex:=5;
    table1.next;
   end;
  end;
 end;
end;procedure Tmainfrm.C3Click(Sender: TObject);
var changeto:string;
begin
  table1.filter:='';
  table1.filtered:=true;
   if table1.locate('name',treeView1.selected.text,[]) then
   begin
   changeto:=inputbox('修改名称','修改 '+treeview1.selected.text+' 为:','');
   if changeto<>'' then
   begin
   if table1.canmodify then
   begin
  table1.Edit;
  table1.fieldByname('name').value:=changeto;
  table1.post;
  FormCreate(Sender);
  treeView1.FullExpand;
   end;
  end;
  end
 else
  ShowMessage('数据操作有误,请重试');
end;procedure Tmainfrm.PopupMenu1Popup(Sender: TObject);
begin
   D2.Enabled:=true;
   C3.Enabled:=true;
       d2.Caption:='删除'''+TreeView1.Selected.Text+'''(&D)';
       c3.Caption:='修改'''+TreeView1.Selected.Text+'''(&C)';
  case TreeView1.selected.ImageIndex of
    4: begin
       if Table3.RecordCount=0 then
       A2.caption:='添加业务记录'
       else
       A2.caption:='编辑业务记录';
       end;
    3: begin
       A2.Caption:='添加新室号';
       end;
   0: begin
       A2.Caption:='添加新地块';
       D2.Enabled:=false;
       C3.Enabled:=false;
       end;
   1:begin
       A2.Caption:='添加新楼幢';
      end;
   2:begin
       A2.Caption:='添加新楼层';
      end;
   end;
end;procedure Tmainfrm.C4Click(Sender: TObject);
begin
if not c4.Checked then
 begin
 c4.Checked:=true;
 l1.Checked:=false;
 PageControl1.ActivePageIndex:=1;
 end;
end;procedure Tmainfrm.N6Click(Sender: TObject);
begin
application.Minimize;
end;procedure Tmainfrm.L1Click(Sender: TObject);
begin
if not L1.Checked then
 begin
 l1.Checked:=true;
 C4.Checked:=false;
 PageControl1.ActivePageIndex:=0;
 end;
end;procedure Tmainfrm.B1Click(Sender: TObject);
begin
treeview1.visible:=false;
end;procedure Tmainfrm.R2Click(Sender: TObject);
begin
treeview1.visible:=true;
end;procedure Tmainfrm.ToolButton5Click(Sender: TObject);
begin
table3.first;
end;procedure Tmainfrm.ToolButton6Click(Sender: TObject);
begin
table3.Prior;
end;procedure Tmainfrm.ToolButton7Click(Sender: TObject);
begin
table3.next;
end;procedure Tmainfrm.ToolButton8Click(Sender: TObject);
begin
table3.Last;
end;procedure Tmainfrm.ToolButton2Click(Sender: TObject);
begin
if MessageDLG('确定要删除房号为("'+label27.caption+'")的这条记录吗?',mtInformation,[mbOK,mbCancel],0)=mrOk then
table3.delete;
end;procedure Tmainfrm.N4Click(Sender: TObject);
begin
if N4.Checked then
begin
ToolBar1.visible:=false;
N4.Checked:=false;
end
else
begin
ToolBar1.visible:=true;
N4.Checked:=true;
end;
end;procedure Tmainfrm.N9Click(Sender: TObject);
begin
if N9.Checked then
begin
panel2.visible:=false;
N9.Checked:=false;
end
else
begin
panel2.visible:=true;
N9.Checked:=true;
end;
end;procedure Tmainfrm.S2Click(Sender: TObject);
begin
if s2.Checked then
begin
Statusbar1.visible:=false;
s2.Checked:=false;
end
else
begin
Statusbar1.visible:=true;
s2.Checked:=true;
end;
end;
procedure Tmainfrm.ToolButton1Click(Sender: TObject);
begin
if table3.FieldByName('room').asstring='' then
begin
if table3.canmodify then
 begin
 table3.edit;
 table3.fieldByName('room').value:=TreeView1.selected.Text;
 table3.fieldByName('floor').value:=TreeView1.selected.Parent.Text;
 table3.fieldByName('house').value:=TreeView1.selected.Parent.Parent.Text;
 table3.fieldByName('block').value:=TreeView1.selected.Parent.Parent.Parent.Text;
 end;
end; 
saleEditFrm.show;
end;procedure Tmainfrm.A3Click(Sender: TObject);
begin
houseInfoEditFrm.Show;
end;procedure Tmainfrm.PageControl1Change(Sender: TObject);
begin
if PageControl1.ActivePageIndex=0 then
 begin
 L1.Checked:=true;
 C4.Checked:=false;
 end
else
 begin
 L1.Checked:=false;
 C4.Checked:=true;
 end;
end;procedure Tmainfrm.V3Click(Sender: TObject);
begin
table3.filter:='';
table3.filtered:=true;
Table3.filter:='room='+DBGrid1.Fields[0].Text;
Table3.filtered:=true;
CardReportFrm.QuickRep1.Preview;
end;procedure Tmainfrm.V4Click(Sender: TObject);
begin
QReportFrm.QuickRep1.Preview;
end;function GetTreeViewFullPath():string;
   var CurNode:TtreeNode;father:string;
   begin
    CurNode:=mainfrm.Treeview1.selected;
    while CurNode.Parent<>nil do
    begin
     father:=CurNode.Text+'→'+father;
     CurNode:=CurNode.Parent;
    end;
  Result:=father;
end;procedure Tmainfrm.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
if Table3.Modified then
 begin
 if MessageDlg('数据曾更改过,是否存盘?',mtConfirmation, [mbYes, mbNo], 0) = mrYes then
  Table3.Post
 end;
end;procedure Tmainfrm.TreeView1Change(Sender: TObject; Node: TTreeNode);
var type_id,seltext,selTextFather,father:string;CurNode:TtreeNode;
begin
seltext:=treeview1.selected.text;
CurNode:=TreeView1.Selected;
toolButton1.Enabled:=false;
 if CurNode.ImageIndex=3 then selTextFather:=CurNode.parent.Text
 else if CurNode.ImageIndex=4 then
 begin
 father:=CurNode.Text;
 toolButton1.Enabled:=true;
 end;
father:=GetTreeViewFullPath()+father;
Label16.Caption:=father;
type_id:=flist(seltext,selTextFather);
 if  Treeview1.Selected.ImageIndex=0 then table3.filter:=''
  else if type_id='0' then table3.filter:='block='''+selText+''''
  else if type_id='1' then table3.filter:='house='''+selText+''''
  else if type_id='2' then table3.filter:='floor='''+selText+''' and house='''+TreeView1.Selected.Parent.Text+''''
  else if type_id='3' then table3.filter:='room='''+selText+''' and house='''+TreeView1.Selected.Parent.Parent.Text+''''
  else  table3.filter:='';
 table3.Filtered:=true;
end;procedure Tmainfrm.SIMTELA1Click(Sender: TObject);
begin
SplashFrm := TSplashFrm.Create(Application);
splashfrm.BorderStyle:=bsDialog;
splashfrm.Caption:='关于 simtel售楼管理系统';
splashfrm.Show;
splashfrm.update;
//splashform.button1.visible:=true;
end;procedure Tmainfrm.DBGrid1DblClick(Sender: TObject);
begin
 if table3.FieldByName('room').Asstring<>'' then
  PageControl1.ActivePageIndex:=1
 else if TreeView1.Selected.ImageIndex=4 then
 ToolButton1.Click;
end;procedure Tmainfrm.QReportPopPopup(Sender: TObject);
begin
 if TreeView1.Visible then
  begin
  b1.Enabled:=true;
  r2.Enabled:=false;
  end
  else begin
  b1.Enabled:=false;
  r2.Enabled:=true;
  end;
end;procedure Tmainfrm.ToolButton11Click(Sender: TObject);
begin
  ShellExecute (Handle, 'open',
     PChar ('c:\windows\calc.exe'), '', '', sw_ShowNormal);
end;procedure Tmainfrm.SpeedButton1Click(Sender: TObject);
begin
  ShellExecute (Handle, 'open',
     PChar ('http://www.xts.com.cn'), '', '', sw_ShowNormal);
end;procedure Tmainfrm.ScrollBar1Change(Sender: TObject);
begin
//SendMessage(Panel1.Handle, EM_SCROLLCARET, 0, 10);
//SendMessage(Panel1.Handle, EM_SCROLL, SB_LINEDOWN, 0)
//PostMessage(GroupBox3.Handle, WM_VSCROLL, SB_LINEDOWN, 0);
PostMessage(panel1.Handle, WM_VSCROLL, SB_LINEUP, 0)
end;procedure Tmainfrm.S4Click(Sender: TObject);
begin
setCenterFrm.Show;
end;procedure Tmainfrm.DBGrid1CellClick(Column: TColumn);
begin
 if table3.FieldByName('room').asString<>'' then
 label16.caption:=Table3.fieldByName('block').AsString+'→'+Table3.fieldByName('House').AsString+'→'+Table3.fieldByName('floor').AsString+'→'+Table3.fieldByName('room').AsString;end;procedure Tmainfrm.Table3AfterScroll(DataSet: TDataSet);
begin
 if table3.Eof then
 begin
 ToolButton7.Enabled:=false;
 ToolButton8.Enabled:=false;
 end
 else if  table3.Bof then
 begin
 ToolButton5.Enabled:=false;
 ToolButton6.Enabled:=false;
 end
 else
 begin
 ToolButton5.Enabled:=true;
 ToolButton6.Enabled:=true;
 ToolButton7.Enabled:=true;
 ToolButton8.Enabled:=true;
 end; if table3.FieldByName('room').AsString='' then
 begin
 label27.caption:='没有指定房号或者该房号业务记录为空,禁止编辑';
 pageControl1.Pages[1].Enabled:=false;
 end
 else
 begin
 pageControl1.Pages[1].Enabled:=true;
 label27.caption:=table3.fieldbyName('block').AsString+'→'+table3.fieldbyName('house').AsString+'→'+table3.fieldbyName('floor').AsString+'→'+table3.fieldbyName('room').AsString;
 end;
end;procedure Tmainfrm.Table3PostError(DataSet: TDataSet; E: EDatabaseError;
  var Action: TDataAction);
begin
ShowMessage('警告! 数据存盘失败!');
Exit;
end;end.-------------MainFrm Code ---The End-----------------------------

Answer 5

呵呵！
不要当作垃圾哦
我给all up 加分怎么没反应?
还是显示0