求救 table1:cannot perform this operation on a closed dataset!

[oneal3417]

近日用delphi写了如下代码，运行也成功！可是输完数据后点保存按钮就提示table1:cannot perform this operation on a closed dataset! 数据库是access，table1，query1连接正常。如果注释掉以下代码则运行正常！！望高手们指教
procedure Taddfrm.FormCreate(Sender: TObject);
var
maxNO,tmp:integer;
begin
rydate.Date:=now;
cydate.Date:=now;
with table1 do
begin
Open;
First;
maxNO:=FieldByName('hz_num').AsInteger;
while not eof do
begin
tmp:=FieldByName('hz_num').AsInteger;
if maxNO<tmp then maxNO:=tmp;
next;
end;
close;
end;
edit1.Text:=inttostr(maxNO+1);
end;
全部代码如下：
unit Unit3;

interface

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

type
Taddfrm = class(TForm)
PageControl1: TPageControl;
TabSheet1: TTabSheet;
Label5: TLabel;
Label6: TLabel;
Label7: TLabel;
Label8: TLabel;
Label9: TLabel;
Label10: TLabel;
Label11: TLabel;
Label12: TLabel;
Label13: TLabel;
Edit3: TEdit;
ComboBox1: TComboBox;
Edit4: TEdit;
ComboBox2: TComboBox;
ComboBox3: TComboBox;
Edit5: TEdit;
rydate: TDateTimePicker;
cydate: TDateTimePicker;
Edit6: TEdit;
Button2: TButton;
Table1: TTable;
Query1: TQuery;
Bevel1: TBevel;
Bevel2: TBevel;
Label1: TLabel;
Edit1: TEdit;
Label2: TLabel;
Label3: TLabel;
Label4: TLabel;
Edit2: TEdit;
Edit7: TEdit;
Edit8: TEdit;
DBGrid1: TDBGrid;
DataSource1: TDataSource;
procedure Button2Click(Sender: TObject);
procedure FormCreate(Sender: TObject);


private
{ Private declarations }
public
{ Public declarations }
end;

var
addfrm: Taddfrm;

implementation

{$R *.dfm}

procedure Taddfrm.Button2Click(Sender: TObject);
var
flag:boolean;
begin
flag:=true;
if edit2.Text='' then flag:=false;
if edit3.Text='' then flag:=false;
if edit4.Text='' then flag:=false;
if edit5.Text='' then flag:=false;
if edit6.Text='' then flag:=false;
if edit7.Text='' then flag:=false;
if flag then
with table1 do
begin
Append;
FieldValues['hz_num']:=edit1.Text;
FieldValues['hz_name']:=edit2.Text;
FieldValues['hz_sex']:=combobox1.Text;
FieldValues['hz_age']:=edit3.Text;
FieldValues['hz_class']:=combobox2.Text;
FieldValues['jb_class']:=combobox3.Text;
FieldValues['ry_date']:=rydate.Date;
FieldValues['cy_date']:=cydate.Date;
FieldValues['fz_doc']:=edit4.Text;
FieldValues['lx_name']:=edit5.Text;
FieldValues['lx_phone']:=edit6.Text;
FieldValues['lx_address']:=edit7.Text;
FieldValues['bz']:=edit8.Text;
Post;
showmessage('添加信息成功！');
end
else begin
showmessage('请补全信息！');
edit2.SetFocus;
end;
with query1 do //同步刷新dbgrid
begin
Close;
SQL.Clear;
SQL.Add('select * from hz_msg');
try
Open;
FieldByName('hz_num').DisplayLabel:='患者编号';
FieldByName('hz_name').DisplayLabel:='姓名';
FieldByName('hz_sex').DisplayLabel:='性别';
FieldByName('hz_age').DisplayLabel:='年龄';
FieldByName('hz_class').DisplayLabel:='病人类别';
FieldByName('jb_class').DisplayLabel:='疾病类型';
FieldByName('ry_date').DisplayLabel:='入院时间';
FieldByName('cy_date').DisplayLabel:='出院时间';
FieldByName('fz_doc').DisplayLabel:='负责医生';
FieldByName('lx_name').DisplayLabel:='联系人';
FieldByName('lx_phone').DisplayLabel:='联系电话';
FieldByName('lx_address').DisplayLabel:='联系地址';
FieldByName('bz').DisplayLabel:='备注';
except
ExecSQL;
end;
end;
edit2.Text:='';
edit3.Text:='';
combobox1.ItemIndex:=0;
edit4.Text:='';
combobox2.ItemIndex:=0;
combobox3.ItemIndex:=0;
edit5.Text:='';
edit6.Text:='';
edit7.Text:='';
edit8.Text:='';
edit1.SetFocus;
end;


procedure Taddfrm.FormCreate(Sender: TObject);
var
maxNO,tmp:integer;
begin
rydate.Date:=now;
cydate.Date:=now;
with table1 do
begin
Open;
First;
maxNO:=FieldByName('hz_num').AsInteger;
while not eof do
begin
tmp:=FieldByName('hz_num').AsInteger;
if maxNO<tmp then maxNO:=tmp;
next;
end;
close;
end;
edit1.Text:=inttostr(maxNO+1);
end;
end.

[qingyingnxu]

table1所连接的数据表你设置好了没,出现这种错误,一般都是因为,数据集控件没有被激活或是表没设置好.

[RoverX]

数据集没有打开。

[oneal3417]

[Quote=引用 1 楼 qingyingnxu 的回复:]
table1所连接的数据表你设置好了没,出现这种错误,一般都是因为,数据集控件没有被激活或是表没设置好.
[/Quote]

table1.active:=true;
这个都设置好了！！！结果是一样的！运行没问题！一点按保存行程序就报错！！
删除掉这个代码就正常！！
procedure Taddfrm.FormCreate(Sender: TObject);
var
maxNO,tmp:integer;
begin
rydate.Date:=now;
cydate.Date:=now;
with table1 do
begin
Open;
First;
maxNO:=FieldByName('hz_num').AsInteger;
while not eof do
begin
tmp:=FieldByName('hz_num').AsInteger;
if maxNO <tmp then maxNO:=tmp;
next;
end;
close;
end;
edit1.Text:=inttostr(maxNO+1);
end;

[支持中文哦]

begin
tmp:=FieldByName('hz_num').AsInteger;
if maxNO <tmp then maxNO:=tmp;
next;
end;
close; //----------------看这行，循环完毕后，你把table1关闭了
end;
edit1.Text:=inttostr(maxNO+1);
end;

[JeffChung]

在保存按钮的 Append; 前面加一个open;

4楼的被错误的代码缩进忽悠了，呵呵

[qian_longN1]

begin
tmp:=FieldByName('hz_num').AsInteger;
if maxNO <tmp then maxNO:=tmp;
next;
end;
close; 十有八九它的问题了，好好看看吧，肯定循环中给关了。。。
end;
edit1.Text:=inttostr(maxNO+1);
end;

[xjcheng]

[Quote=引用 6 楼 qian_longN1 的回复:]
begin
tmp:=FieldByName('hz_num').AsInteger;
if maxNO <tmp then maxNO:=tmp;
next;
end;
close; 十有八九它的问题了，好好看看吧，肯定循环中给关了。。。
end;
edit1.Text:=inttostr(maxNO+1);
end;
[/Quote]
支持6楼,还要注意语法格式.

[iamduo]

草，有没有搞错。
这种代码，你们还有兴趣看啊？
设置一个断点，运行到断点的时候，按F8，一个个看过来。

[oneal3417]

谢谢楼上各位了！！问题就是处在append前面少了个open；