帮我看看吧,大侠 ( 积分: 200 )

我想做一个模拟考试系统,我的代码如下:
问题1.我的题目是由dbmemo1和一张图片组成,现在是我点击dbnavigator1的aferscroll后,只有dbmemo1中的题可以变化,图片总是显示第一题的,咋回事那?
问题2.再有那个num的数好像总是没有变化,不懂,蒙了
请大侠帮我看看吧

unit Unit3;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ComCtrls, Menus, DB, ADODB, StdCtrls, DBCtrls, ExtCtrls;

type
TForm3 = class(TForm)
MainMenu1: TMainMenu;
start: TMenuItem;
dzja: TMenuItem;
mssp: TMenuItem;
mnkc: TMenuItem;
out: TMenuItem;
StatusBar1: TStatusBar;
start1: TMenuItem;
daja1: TMenuItem;
mssp1: TMenuItem;
out1: TMenuItem;
ADOConnection1: TADOConnection;
ADOQuery1: TADOQuery;
ADOQuery2: TADOQuery;
DBMemo1: TDBMemo;
DataSource1: TDataSource;
DBText1: TDBText;
mnkc1: TMenuItem;
mnkc2: TMenuItem;
ComboBox1: TComboBox;
Button1: TButton;
DBNavigator1: TDBNavigator;
Image1: TImage;
Label1: TLabel;
Label2: TLabel;
procedure start1Click(Sender: TObject);
procedure mssp1Click(Sender: TObject);
procedure daja1Click(Sender: TObject);
procedure out1Click(Sender: TObject);
procedure ComboBox1Change(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure ADOQuery1AfterScroll(DataSet: TDataSet);

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

//设置用户自定义类
type student=Record
TestPaper:string;
Score:integer;
end;

type answer=Record
standard:string;
ecaminee:string;
result:integer;
path:string;
end;

var
Form3: TForm3;

implementation

uses main, Unit2, Unit1;

//全局变量
var
stu:student;
examcount:integer;
ans:array of answer;

{$R *.dfm}


procedure TForm3.start1Click(Sender: TObject);
begin
form3.hide;
mainform.show;
end;

procedure TForm3.mssp1Click(Sender: TObject);
begin
form3.hide;
form2.show;
end;

procedure TForm3.daja1Click(Sender: TObject);
begin
form3.hide;
form1.show;
end;

procedure TForm3.out1Click(Sender: TObject);
begin
mainform.close;
end;

procedure TForm3.ComboBox1Change(Sender: TObject);
begin
if ComboBox1.ItemIndex=0 then
begin
stu.TestPaper:='模拟题1';
button1.Caption:='模拟题1';
end;
if ComboBox1.ItemIndex=1 then
begin
stu.TestPaper:='模拟题2';
button1.Caption:='模拟题2';
end;
end;

procedure TForm3.Button1Click(Sender: TObject);
var
allpath:string;
num:integer;
begin
//取题
with ADOQuery1 do
begin
close;
sql.clear;
sql.Add('select * from '+stu.TestPaper+' order by 题号');
open;

DBMemo1.DataSource:=DataSource1;
DBText1.DataSource:=DataSource1;
DBText1.DataField:='题号';
DBMemo1.DataField:='题目';

examCount:=RecordCount;
SetLength(ans,examCount+1);

num:=ADOQuery1.FieldByName('题号').value;
label1.caption:=inttostr(num);
ans[num].path:=ADOQuery1.FieldByName('路径').Value;
allpath:=ExtractFilePath(Application.ExeName)+ans[num].path;
Image1.Picture.LoadFromFile(allpath);
end;

end;

procedure TForm3.ADOQuery1AfterScroll(DataSet: TDataSet);
var
allpath1:string;
num1:integer;
begin
with ADOQuery1 do
begin
num1:=ADOQuery1.FieldByName('题号').value;
label1.caption:=inttostr(num1);
ans[num1].path:=ADOQuery1.FieldByName('路径').Value;
allpath1:=ExtractFilePath(Application.ExeName)+ans[num1].path;
Image1.Picture.LoadFromFile(allpath1);
end;
end;

end.

with ADOQuery1 do
begin
...
next;//加上这句
end;

我加了,还是不行啊,是在procedure TForm3.Button1Click(Sender: TObject);里加
,还是在procedure TForm3.ADOQuery1AfterScroll(DataSet: TDataSet);里加,还是两个地方都要加?

没发现有问题

allpath:=ExtractFilePath(Application.ExeName)+ADOQuery1.FieldByName('路径').Value;
Image1.Picture.LoadFromFile(allpath);

这个我试过了,不行,我现在发现我点击dbnavigator1的aferscroll后,ADOQuery1.FieldByName('路径').Value和ADOQuery1.FieldByName('题号')的值根本就不变化,DBText1.DataField:='题号'和DBMemo1.DataField:='题目'的值是变化的,这个应该是主要原因吧,怎么回事了,急死了