login form creation in mfc - mfc

Question

I wrote a code in mfc for login form
my code is here
// login1Dlg.cpp : implementation file
//
#include "stdafx.h"
#include "login1.h"
#include "login1Dlg.h"
#include "afxdialogex.h"
//#include "LOGINDlg.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#endif
// Clogin1Dlg dialog
Clogin1Dlg::Clogin1Dlg(CWnd* pParent /*=NULL*/)
: CDialogEx(Clogin1Dlg::IDD, pParent)
{
m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
m_username = _T("");
m_password = _T("");
}
void Clogin1Dlg::DoDataExchange(CDataExchange* pDX)
{
CDialogEx::DoDataExchange(pDX);
DDX_Text(pDX, IDC_USERNAME_EDIT, m_username);
DDX_Text(pDX, IDC_PASSWORD_EDIT, m_password);
}
BEGIN_MESSAGE_MAP(Clogin1Dlg, CDialogEx)
ON_WM_PAINT()
ON_WM_QUERYDRAGICON()
ON_BN_CLICKED(IDC_OK_BUTTON, &Clogin1Dlg::OnBnClickedOkButton)
END_MESSAGE_MAP()
// Clogin1Dlg message handlers
BOOL Clogin1Dlg::OnInitDialog()
{
CDialogEx::OnInitDialog();
// Set the icon for this dialog. The framework does this automatically
// when the application's main window is not a dialog
SetIcon(m_hIcon, TRUE); // Set big icon
SetIcon(m_hIcon, FALSE); // Set small icon
// TODO: Add extra initialization here
return TRUE; // return TRUE unless you set the focus to a control
}
// If you add a minimize button to your dialog, you will need the code below
// to draw the icon. For MFC applications using the document/view model,
// this is automatically done for you by the framework.
void Clogin1Dlg::OnPaint()
{
if (IsIconic())
{
CPaintDC dc(this); // device context for painting
SendMessage(WM_ICONERASEBKGND, reinterpret_cast<WPARAM>(dc.GetSafeHdc()), 0);
// Center icon in client rectangle
int cxIcon = GetSystemMetrics(SM_CXICON);
int cyIcon = GetSystemMetrics(SM_CYICON);
CRect rect;
GetClientRect(&rect);
int x = (rect.Width() - cxIcon + 1) / 2;
int y = (rect.Height() - cyIcon + 1) / 2;
// Draw the icon
dc.DrawIcon(x, y, m_hIcon);
}
else
{
CDialogEx::OnPaint();
}
}
// The system calls this function to obtain the cursor to display while the user drags
// the minimized window.
HCURSOR Clogin1Dlg::OnQueryDragIcon()
{
return static_cast<HCURSOR>(m_hIcon);
}
void Clogin1Dlg::OnBnClickedOkButton()
{
// TODO: Add your control notification handler code here
UpdateData();
char UsernameFromFile[20], PasswordFromFile[20];
FILE *fleCredentials;
bool ValidLogin = false;
if(m_username == "" )
{
AfxMessageBox(_T("You must provide a username and a password or click Cancel"));
return;
}
if( m_password == "" )
{
AfxMessageBox(_T("Invalid Login"));
return;
}
try {
// Open the file for reading
fleCredentials = fopen("credentials.txt", "r");
// Scan the file from beginning to end
while( !feof(fleCredentials) )
{
//Read a username
fscanf(fleCredentials, "%s", UsernameFromFile);
//Compare the typed username with the username from the file
if(strcmp((LPCTSTR)m_username, UsernameFromFile) == 0 )
{
// With the current username, retrieve the corresponding password
fscanf(fleCredentials, "%s", PasswordFromFile);
//Compare the typed password with the one on file
if( strcmp((LPCTSTR)m_password, PasswordFromFile) == 0 )
{
ValidLogin = true;
}
else
ValidLogin = false;
}
}
if( ValidLogin == true )
OnOK();
else
{
AfxMessageBox(_T("Invalid Credentials. Please try again"));
//this->m_EditUsername.SetFocus();
}
fclose(fleCredentials);
}
catch(...)
{
AfxMessageBox(_T("Could not validate the credentials"));
}
UpdateData(FALSE);
}
But I got this error
Error 3 error C2664: 'strcmp' : cannot convert parameter 1 from 'LPCTSTR' to 'const char *' e:\win32\test\login1\login1dlg.cpp 130 1 login1
i want little help from u

Answer 1

try Change the 2 if statement code to this
if(strcmp((LPSTR)(LPCTSTR)m_username, UsernameFromFile) == 0 )
if( strcmp((LPSTR)(LPCTSTR)m_password, PasswordFromFile) == 0 )

Answer 2

from the error i can see cannot convert parameter 1 from 'LPCTSTR' to 'const char *'
strcmp is used with char ANSI but try using the Unicode version of it instead
as you know LPCTSTR is dependent on unicode or ansi if you use unicode library use the following function wcscmp for more information help at msdn
also for types windows data types on msdn
so you replace strcmp at line 129 and 135 with wcscmp if this solve the problem just let us know