unit1.pas

delphi编写的选课系统

unit Unit1;

interface

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

type
  TLoginForm = class(TForm)
    StatusBar1: TStatusBar;
    ADOQuery0: TADOQuery;
    DataSource0: TDataSource;
    ADOConnection0: TADOConnection;
    PageControl1: TPageControl;
    TabSheet1: TTabSheet;
    Panel1: TPanel;
    Label3: TLabel;
    Label1: TLabel;
    Label2: TLabel;
    username: TEdit;
    PassWord: TEdit;
    login1: TButton;
    exit1: TButton;
    TabSheet2: TTabSheet;
    Panel2: TPanel;
    Label4: TLabel;
    Label5: TLabel;
    Label6: TLabel;
    Label7: TLabel;
    username2: TEdit;
    password2: TEdit;
    login2: TButton;
    exit2: TButton;
    TabSheet3: TTabSheet;
    Label8: TLabel;
    Label9: TLabel;
    Label10: TLabel;
    username3: TEdit;
    password3: TEdit;
    login3: TButton;
    exit3: TButton;
    TabSheet4: TTabSheet;
    Panel3: TPanel;
    Label11: TLabel;
    Label12: TLabel;
    Label13: TLabel;
    username4: TEdit;
    password4: TEdit;
    login4: TButton;
    eixt4: TButton;
    procedure login1Click(Sender: TObject);
    procedure PassWordKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure usernameKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure exit1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure login2Click(Sender: TObject);
    procedure login3Click(Sender: TObject);
    procedure password2KeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure password3KeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure eixt4Click(Sender: TObject);
    procedure login4Click(Sender: TObject);
    procedure username4KeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure password4KeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
  private
    { Private declarations }     
  public
     
    { Public declarations }
  end;

var
  LoginForm: TLoginForm;
  user:string;
implementation

uses Unit2, Unit5, StudentInfoUnit, GradeUnit;

{$R *.dfm}

procedure TLoginForm.login1Click(Sender: TObject);
var sqlstr:string;
begin
 if UserName.Text=''
   then messagedlg(#10'请输入用户名.', mtwarning,[mbOk],0)            //用户名为空
   else if PassWord.Text=''
          then messagedlg(#10'请输入密码.', mtwarning,[mbOk],0)       //密码为空
          else begin
               user:=username.Text;                                   //user赋值,全局变量

               ADOQuery0.Close;
               ADOQuery0.SQL.Clear;
               ADOQuery0.SQL.add('select * from student where sno=:Pusername');
               ADOQuery0.Parameters.ParamByName('Pusername').value:=username.text;
               ADOQuery0.open;                        //数据库连接

               if  ADOQuery0.Eof then messagedlg(#10'用户名不正确,请重试!', mtWarning,[mbOk],0)
                 else if ADOQuery0.FieldByName('idno').value=Password.text
                     then  begin                                          //验证用户名/密码
                            Application.CreateForm(TMainForm, MainForm);
                            LoginForm.hide;
                            MainForm.show;

                       end
                       else messagedlg(#10'密码不正确,请重试!', mtWarning,[mbOk],0);
               end;
end;

procedure TLoginForm.PassWordKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);                           //密码框内按回车,调用loginClick事件
begin
  if key=13 then  login1Click(sender);               
end;

procedure TLoginForm.usernameKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);                             //用户名框内按回车,模拟Tab键
begin
  if key=13 then PostMessage(LoginForm.Handle,WM_KEYDOWN,VK_TAB,0);
end;

procedure TLoginForm.exit1Click(Sender: TObject); // 程序退出
begin
     application.Terminate;
end;


procedure TLoginForm.FormCreate(Sender: TObject);   //焦点设置为username输入框
begin
  LoginForm.SetFocusedControl(username);
end;

procedure TLoginForm.login2Click(Sender: TObject);
begin
 if UserName2.Text=''
   then messagedlg(#10'请输入用户名.', mtwarning,[mbOk],0)            //用户名为空
   else if PassWord2.Text=''
          then messagedlg(#10'请输入密码.', mtwarning,[mbOk],0)       //密码为空
          else begin
               ADOQuery0.Close;
               ADOQuery0.SQL.Clear;
               ADOQuery0.SQL.add('select * from admin where username=:Pusername');
               ADOQuery0.Parameters.ParamByName('Pusername').value:=username2.text;
               ADOQuery0.open;                        //数据库连接
                                                     
               if  ADOQuery0.Eof then messagedlg(#10'用户名不正确,请重试!', mtWarning,[mbOk],0)
                 else if ADOQuery0.FieldByName('Password').value=Password2.text
                     then  begin
                            Application.CreateForm(TManageForm, ManageForm);
                            LoginForm.hide;
                            ManageForm.show;
                           end
                       else  messagedlg(#10'密码不正确,请重试!', mtWarning,[mbOk],0);
               end;
end;

procedure TLoginForm.login3Click(Sender: TObject);
begin
 if UserName3.Text=''
   then messagedlg(#10'请输入用户名.', mtwarning,[mbOk],0)            //用户名为空
   else if PassWord3.Text=''
          then messagedlg(#10'请输入密码.', mtwarning,[mbOk],0)       //密码为空
          else begin
               ADOQuery0.Close;
               ADOQuery0.SQL.Clear;
               ADOQuery0.SQL.add('select * from admin where username=:Pusername');
               ADOQuery0.Parameters.ParamByName('Pusername').value:=username3.text;
               ADOQuery0.open;                        //数据库连接
                                                     
               if  ADOQuery0.Eof then messagedlg(#10'用户名不正确,请重试!', mtWarning,[mbOk],0)
                 else if ADOQuery0.FieldByName('Password').value=Password3.text
                     then  begin
                            Application.CreateForm(TStudentInfoForm, StudentInfoForm);
                            LoginForm.hide;
                            StudentInfoForm.show;
                           end
                       else  messagedlg(#10'密码不正确,请重试!', mtWarning,[mbOk],0);
               end;
end;           

procedure TLoginForm.password2KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
 if key=13 then  login2Click(sender);
end;

procedure TLoginForm.password3KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
 if key=13 then  login3Click(sender);
end;

procedure TLoginForm.eixt4Click(Sender: TObject);
begin
  application.Terminate;
end;

procedure TLoginForm.login4Click(Sender: TObject);
begin
 if UserName4.Text=''
   then messagedlg(#10'请输入用户名.', mtwarning,[mbOk],0)            //用户名为空
   else if PassWord4.Text=''
          then messagedlg(#10'请输入密码.', mtwarning,[mbOk],0)       //密码为空
          else begin
               ADOQuery0.Close;
               ADOQuery0.SQL.Clear;
               ADOQuery0.SQL.add('select * from admin where username=:Pusername');
               ADOQuery0.Parameters.ParamByName('Pusername').value:=username4.text;
               ADOQuery0.open;                        //数据库连接
                                                     
               if  ADOQuery0.Eof then messagedlg(#10'用户名不正确,请重试!', mtWarning,[mbOk],0)
                 else if ADOQuery0.FieldByName('Password').value=Password4.text
                     then  begin
                            Application.CreateForm(TGradeForm, GradeForm);
                            LoginForm.hide;
                            GradeForm.show;
                           end
                       else  messagedlg(#10'密码不正确,请重试!', mtWarning,[mbOk],0);
               end;
end;

procedure TLoginForm.username4KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
if key=13 then PostMessage(LoginForm.Handle,WM_KEYDOWN,VK_TAB,0);
end;



procedure TLoginForm.password4KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
   if key=13 then  login4Click(sender);
end;

end

.