Question

Delphi中，登陆之后怎样显示主界面？

代码如下

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, DB, ADODB, StdCtrls, Buttons, jpeg, ExtCtrls;

type
Tlogin = class(TForm)
Image1: TImage;
SpeedButton1: TSpeedButton;
SpeedButton2: TSpeedButton;
ADOConnection1: TADOConnection;
ADOQuery1: TADOQuery;
DataSource1: TDataSource;
Edit1: TEdit;
Edit2: TEdit;
procedure SpeedButton2Click(Sender: TObject);
procedure SpeedButton1Click(Sender: TObject);
procedure plogin;
private
{ Private declarations }
public
{ Public declarations }
end;

var
login: Tlogin;
m:integer = 0;
s:boolean = false;
czy:string;

implementation

{$R *.dfm}

procedure Tlogin.SpeedButton2Click(Sender: TObject);
begin
if messagebox(self.Handle,'真的要退出系统吗？','学生缴费管理系统',mb_yesno+mb_iconquestion)=idyes then
application.Terminate;
end;

procedure Tlogin.plogin;
begin
with ADOQuery1 do
begin
close;
sql.Clear;
sql.Add('select * from 登录信息 where username = :a and password = :b');
parameters.ParamByName('a').Value:=trim(edit1.Text);
parameters.ParamByName('b').Value:=trim(edit2.Text);
open;
end;
if ADOQuery1.RecordCount>0 then
begin
czy:=ADOQuery1.FieldByName('username').Value;
s:=true;
close;
end
else
if m<3 then
begin
application.MessageBox('用户名或密码错误，请重新输入！','提示',64);
edit1.Clear;
edit2.Clear;
edit1.SetFocus;
end
else
begin
application.MessageBox('您无权使用本系统！','提示',64);
Application.Terminate;
end

end;

procedure Tlogin.SpeedButton1Click(Sender: TObject);
begin
m:=m+1;
if edit1.Text='' then
application.MessageBox('请输入用户名','提示',64)
else
if edit2.Text='' then
application.MessageBox('请输入密码','提示',64)
else
plogin;
end;

end.
现在代码实现的是，输入用户名密码，关闭登陆界面，不显示主界面。有没有高手指点一下

Answer 1

...
if ADOQuery1.RecordCount>0 then
begin
czy:=ADOQuery1.FieldByName('username').Value;
s:=true;
close;
mainform.show;//在这里加入对主窗体的调用就可以了
end
else
if m<3 then
...