Graduation project C + + graduation thesis based on MFC laboratory room management system | looking for the treasure of C Station

The main control terminal is responsible for the verification of the login of the student terminal and the remote control of the student terminal. The specific functional modules are as follows:

(1) System setting module

1) Communication setting: the communication port setting between the main control end and the controlled end.

2) Password modification: modify the unlocking password of the master control terminal.

(2) Account management:

1) Add account: the required fields are: student number, name, class and password.

2) Account modification: modify the specified account. If the student forgets the password, the administrator can modify the password.

3) Batch import: you can import Excel table data containing account information into the database.

4) Batch delete: you can batch delete the queried account numbers.

(3) Routine maintenance:

1) Computer log: record the log of each login and logout of students.

2) Exception log: record the exception log of the student side, such as the failure of the restore card.

3) Database backup: the administrator can backup data regularly

(4) Student side list:

1) List dynamic maintenance: manage student connections and dynamically update them on the list.

2) Message sending: Send a message to the selected student terminal.

3) Remote desktop: Remote Desktop Control for a single student terminal.

4) Remote shutdown: issue shutdown command to the selected student terminal.

5) Remote restart: Send a shutdown command to the selected student terminal.

Student end planning

The student terminal is responsible for locking the screen of the student computer and executing the commands of the main control terminal. The specific functional modules are as follows:

(1) Login module:

1) Hot key shielding: shield the relevant hot keys when the system starts, lock the screen and display the login box.

2) Login verification: send the student number and password to the server. If the verification is successful, it will be unlocked automatically.

3) Administrator unlocking: the administrator can unlock the student terminal by using the unlocking password.

(2) Communication module with server:

1) Receive message: receive the message from the server and automatically prompt on the desktop.

2) Receive remote control: respond to various controls required by the server.

3) Exception monitoring: send the exceptions on the student side to the server.

4) Change Password: students change their login password.

(3) Student side setting: it can only be used in the management mode. Set the communication mode and unlock password.

Functional module structure design

System operation flow chart

System database design

Data sheet design (part)

For the laboratory room management system, the main function is to control the computer on the student side, and the database design is relatively simple. The system adopts SQL 2000 database, and the name of the system database is db_LabMS, database db_LabMS includes 3 data sheets. The following is a brief description of the database and the structure of the data table.

(1) User data sheet

The user saves the account information of the system user. The data table is named "student", and the structure is shown in table 4-1.

Table 4-1 user table (student)

Serial number	Listing	data type	length	identification	Primary key	Allow null	Default value	explain
1	s_id	int	4	yes		no		Automatic numbering ID
2	s_xh	nvarchar	12		yes	no		Student number
3	s_name	nvarchar	8			no		name
4	s_pwd	nvarchar	12			no		password
5	s_class	nvarchar	30			no		class

(2) Data sheet of computer operation record

It is used to save the data recorded by students on the computer. The data table is named "log", and the structure is shown in Table 4-2.

Table 4-2 data sheet of computer log

Serial number	Listing	data type	length	identification	Primary key	Allow null	Default value	explain
1	l_id	int	4	yes	yes	no		Automatic numbering ID
2	s_xh	nvarchar	12			no		Student number
3	l_type	nvarchar	8			no		type
4	l_time	datetime	8			no	(getdate())	time
5	l_pc	nvarchar	20			no		Pc name

(3) Exception data sheet

It is used to save the abnormal information of the student machine. The data table is named "exception", and the structure is shown in table 4-3.

Table 4-3: exception

Serial number	Listing	data type	length	identification	Primary key	Allow null	Default value	explain
1	e_id	int	4	yes	yes	no		Automatic numbering ID
2	e_type	nvarchar	50			yes		Exception type
3	e_state	nvarchar	8			yes	(N 'not processed')	state
4	e_pc	nvarchar	20			yes		Pc name
5	e_time	datetime	8			yes	(getdate())	Abnormal occurrence time

(4) Host list data sheet

It is used to save the list of currently logged in student computers. The data table is named "list", and the structure is shown in table 4-4.

Table 4-4 list of hosts

Serial number	Listing	data type	length	identification	Primary key	Allow null	Default value	explain
1	l_xh	nvarchar	12			yes		Student number
2	l_mac	nvarchar	12			yes		MAC address
3	l_pc	nvarchar	20			yes		PC name
4	l_time	datetime	8			yes	(getdate())	Landing time

View design (part)

From the perspective of users, a view is to view the data in the database from a specific perspective. From the inside of the database system, the view is composed of data in one or more tables. From the outside of the database system, the view is like a table. The general operations that can be performed on the table can be applied to the view, such as query, insert, modify, delete, etc. [3]

The logview view creation statement of the system is as follows:

CREATE VIEW dbo.logview

AS

SELECT dbo.[log].l_time, dbo.[log].s_xh, dbo.student.s_name, dbo.[log].l_type,

      dbo.[log].l_pc, dbo.student.s_class

FROM dbo.[log] INNER JOIN

      dbo.student ON dbo.[log].s_xh = dbo.student.s_xh

Trigger design (part)

A trigger is a special stored procedure , its execution is not called by the program or started manually, but triggered by events. For example, when a table is operated (insert, delete, update), it will be activated for execution. [4] When inserting into the log table, it will trigger the update of the list table, which saves the current host list.

Trigger trig_ The updatelist creation statement is as follows:

CREATE TRIGGER trig_updatelist ON dbo.[log]

FOR insert

AS

if exists(select l_mac from inserted where l_mac not in (select l_mac from [list]))

begin

insert into [list](l_pc,l_mac,l_xh) select l_pc,l_mac,s_xh from inserted

end

else

begin

delete [list] where l_mac=(select l_mac from inserted)

end

System implementation (part)

HOOK message HOOK design

5.1.1 general

When the student terminal starts up, it is necessary to lock the screen, shield the system hotkeys, and protect the lock screen program from being closed. To shield the system hotkey, HOOK technology needs to be used. HOOK is a platform of Windows message processing mechanism. The application program can set subroutines on it to monitor some messages of the specified Window, and the monitored Window can be created by other processes. [5] When the message arrives, it is processed before the target Window processing function. The HOOK mechanism allows the application to intercept and process Window messages or specific events. Through HOOK technology, some hot keys such as ALT+F4 and ALT+ESC can be shielded, which can effectively protect the screen lock program.

5.1.2 program related code analysis

Generally speaking, the system level hook must be a DLL. The following is a code fragment of a keyboard hook DLL (TaskKeyHook.dll):

//Header file



//TaskKeyHook.h

//

#define DLLIMPORT __declspec(dllimport)



DLLIMPORT BOOL DisableTaskKeys(BOOL bEnable, BOOL bBeep);

DLLIMPORT BOOL AreTaskKeysDisabled();



//Implementation file



// TaskKeyHook.cpp

//

#define _WIN32_WINNT 0x0500 // for KBDLLHOOKSTRUCT

#include <afxwin.h>         // MFC core and standard components



#define DLLEXPORT __declspec(dllexport)



//

// App (DLL) object

//

class CTaskKeyHookDll : public CWinApp {

public:

     CTaskKeyHookDll()  { }

     ~CTaskKeyHookDll() { }

} MyDll;





// The following code indicates that this part is shared among all instances of this DLL

// Low level keyboard hooks must be system level hooks

//

#pragma data_seg (".mydata")

HHOOK g_hHookKbdLL = NULL; // Hook handle

BOOL  g_bBeep = FALSE;     // Beep when illegal key is pressed

#pragma data_seg ()

#pragma comment(linker, "/SECTION:.mydata,RWS") / / tell the linker: create a data sharing segment



//

// Low level keyboard hook

// Intercepting task conversion key: return directly without passing

//

LRESULT CALLBACK MyTaskKeyHookLL(int nCode, WPARAM wp, LPARAM lp)

{

     KBDLLHOOKSTRUCT *pkh = (KBDLLHOOKSTRUCT *) lp;



     if (nCode==HC_ACTION) {

         BOOL bCtrlKeyDown =

              GetAsyncKeyState(VK_CONTROL)>>((sizeof(SHORT) * 8) - 1);



         if ((pkh->vkCode==VK_ESCAPE && bCtrlKeyDown) || // Ctrl+Esc

              // Alt+TAB

              (pkh->vkCode==VK_TAB && pkh->flags & LLKHF_ALTDOWN) ||  

              // Alt+Esc

              (pkh->vkCode==VK_ESCAPE && pkh->flags & LLKHF_ALTDOWN)||

              (pkh->vkCode==VK_LWIN || pkh->vkCode==VK_RWIN)) { // opening menu

                   if (g_bBeep && (wp==WM_SYSKEYDOWN||wp==WM_KEYDOWN))

                       MessageBeep(0); // Beep

                   return 1; // No longer pass to CallNextHookEx, return directly

         }

     }

     return CallNextHookEx(g_hHookKbdLL, nCode, wp, lp);

}





// Is the task key sequence masked - that is, is the keyboard hook installed?

// Note: it is assumed that no other hook does the same thing

//

DLLEXPORT BOOL AreTaskKeysDisabled()

{

     return g_hHookKbdLL != NULL;

}





// Mask task key: install low-level keyboard mechanism

// Returns the current mask flag (TRUE/FALSE)

//

DLLEXPORT BOOL DisableTaskKeys(BOOL bDisable, BOOL bBeep)

{

     if (bDisable) {

         if (!g_hHookKbdLL) {

              g_hHookKbdLL = SetWindowsHookEx(WH_KEYBOARD_LL,

                   MyTaskKeyHookLL, MyDll.m_hInstance, 0);

         }



     } else if (g_hHookKbdLL != NULL) {

         UnhookWindowsHookEx(g_hHookKbdLL);

         g_hHookKbdLL = NULL;

     }

     g_bBeep = bBeep;



     return AreTaskKeysDisabled();

}

TaskKeyHook outputs two functions: DisableTaskKeys and aretaskkeys disabled. The former is installed with WH_KEYBOARD_LL hook; The latter determines whether the hook is installed. The processing idea of this keyboard hook is to intercept hotkeys such as Alt+Tab, Ctrl+Esc, Alt+Esc and Windows key.

Design of full screen transparent login form for students

5.2.1 general

Once the student terminal is started, it will automatically lock the student machine in full screen. The login interface of student end lock screen is shown in Figure 5-1. Its implementation principle is realized through two dialog boxes. The parent dialog box realizes the full screen transparent form, and then the sub dialog box (login box) pops up. The login box hides the border and fills the background with a brush.

Figure 5-1 main window of laboratory room management system

5.2.2 program related code analysis

Main code fragments of full screen transparent login form:

// ClientDlg.cpp : implementation file



void CClientDlg::OnFullScreen()

{



     LONG style = GetWindowLong(m_hWnd, GWL_STYLE);    //Get window style

     ::ShowWindow(m_hWnd, SW_MAXIMIZE);

     style = GetWindowLong(m_hWnd, GWL_STYLE);

     style &= ~(WS_DLGFRAME | WS_THICKFRAME);

     SetWindowLong(m_hWnd, GWL_STYLE, style);          //Set window style

     int cx = GetSystemMetrics(SM_CXSCREEN);

     int cy = GetSystemMetrics(SM_CYSCREEN);

     ::SetWindowPos(m_hWnd, HWND_TOPMOST, -1, -1, cx+3, cy+3, SWP_FRAMECHANGED);//Full screen display



     ::InvalidateRect(m_hWnd,NULL,TRUE);               //Window background to be erased



     SetWindowLong(this->GetSafeHwnd(),GWL_EXSTYLE,

         GetWindowLong(this->GetSafeHwnd(),GWL_EXSTYLE)^0x80000);    //Windows join WS_EX_LAYERED extended attribute

     HINSTANCE hInst = LoadLibrary("User32.DLL");

     if (hInst)

     {

         typedef BOOL (WINAPI *MYFUNC)(HWND,COLORREF,BYTE,DWORD);

         MYFUNC fun = NULL;

         fun = (MYFUNC)GetProcAddress(hInst,"SetLayeredWindowAttributes");    //Gets the pointer to the SetLayeredWindowAttributes function

         if (fun)

              fun(this->GetSafeHwnd(),0,125,2);    //Set the window to translucent

         FreeLibrary(hInst);

     }



     CTaskKeyMgr::Disable(CTaskKeyMgr::ALL, TRUE); //Using Hook tool class to realize hot key shielding



     CLoginDlg dlg=new CLoginDlg();

     dlg.DoModal();                   //Pop up the Mode dialog box and wait for the user to output



     CTaskKeyMgr::Disable(CTaskKeyMgr::ALL, FALSE); //Restore all prohibited things

}

Main code snippet of login box:

// LoginDlg.cpp : implementation file
//
//Fill background
void CLoginDlg::OnPaint() 
{
	CPaintDC dc(this); // device context for painting
	CRect   rect;   
	GetClientRect(&rect);   
	CDC   dcMem;   
	dcMem.CreateCompatibleDC(&dc);   
	CBitmap   bmpBackground;   
	bmpBackground.LoadBitmap(IDB_BITMAP1);  
	BITMAP   bitmap;   
	bmpBackground.GetBitmap(&bitmap);   
	CBitmap   *pbmpOld=dcMem.SelectObject(&bmpBackground);   
	dc.StretchBlt(0,0,rect.Width(),rect.Height(),&dcMem,0,0,   
		bitmap.bmWidth,bitmap.bmHeight,SRCCOPY);  
}
void CLoginDlg::OnLogin() 
{
	// TODO: Add your control notification handler code here
	UpdateData(true);

	if ((m_uid == "")||(m_pwd == ""))         //If the user name is empty
	{		
		MessageBoxA("User name or password cannot be empty");
		GetDlgItem(IDC_UID)->SetFocus();
		return;
	}
	else
	{
		if (m_uid.Find(" ")!=-1)
		{
			MessageBoxA("The user name cannot contain spaces");
			GetDlgItem(IDC_UID)->SetFocus();
			return;
		}else
			if (m_pwd.Find(" ")!=-1)
			{
				MessageBoxA("The password cannot contain spaces");
				GetDlgItem(IDC_PWD)->SetFocus();
				return;
			}

	}
	//Send the user name and password to the server for authentication
	if (CScoketMgr::SendLogin(m_uid,m_pwd))
	{
		CDialog::OnCancel();
	}

}

BOOL CLoginDlg::PreTranslateMessage(MSG* pMsg) 
{
	// Shield the RETURN, PAUSE and ESCAPE keys to prevent the login box from being closed
	if   (pMsg->message==WM_KEYDOWN&&pMsg->wParam==VK_RETURN) 
	{       
		return TRUE;   
	}
	if   (pMsg->message==WM_KEYDOWN&&pMsg->wParam==VK_PAUSE) 
	{       
		return TRUE;   
	}
	if (pMsg->message==WM_KEYDOWN&&pMsg->wParam==VK_ESCAPE)
	{
		return TRUE;
	}

	return CDialog::PreTranslateMessage(pMsg);
}
void CLoginDlg::OnClose() 
{
	// Prevent the login box from being closed

	return;

}

void CLoginDlg::OnUnlock() 
{
	// Unlock
	UpdateData(true);
	CMD5 md5T;
	if (md5T.MD5(m_pwd)==theApp.unlockpwd)       //Verify unlock password
		OnCancel();
}

Thousands of words are omitted here

Resource download

Complete source program + database + paper + instructions for use download: https://download.csdn.net/download/frank2102/19414729

Added by ianwest on Wed, 02 Feb 2022 08:38:33 +0200

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