Fast file download

URLDownloadToFile(NULL,L"http://www.piercemattie.com/blogs/car.bmp",L"d:\\ab.bmp",0,NULL);

Loading JPG images in Picture Control dynamically

1. Add header file add

#include

2. In the SampleDlg.h file add

CString m_csPath;

3. In the OnPaint function

void CSampleDlg::OnPaint()
{

CPaintDC dc(this); // device context for painting

CRect rect1;
CWnd *pWnd=NULL;
pWnd = GetDlgItem(IDC_STATIC_PIC);
if( NULL != pWnd && NULL != pWnd->GetSafeHwnd() )
{
pWnd->GetWindowRect( rect1 );
}

ScreenToClient( rect1 );

HDC hDC = dc.GetSafeHdc();
CImage img;
if( !m_csPath.IsEmpty() )
{
img.Load( m_csPath );
if( !img.IsNull() )
{

int nWidth1 = img.GetWidth();
int nHeight1 = img.GetHeight();

SetStretchBltMode(hDC, HALFTONE);
img.StretchBlt( hDC, rect1.left, rect1.top, rect1.Width(), rect1.Height(), 0, 0, nWidth1, nHeight1, SRCCOPY );

}
}

}

In the button click event

void CSampleDlg::OnBnClickedButton1()
{
TCHAR szFilters[]= _T("Image Files (*.bmp,*.jpg)|*.bmp;*.jpg|All Files (*.*)|*.*||");
CFileDialog objFileDialog( TRUE,0, 0,
OFN_FILEMUSTEXIST | OFN_HIDEREADONLY, szFilters);
CString csPath;

objFileDialog.m_ofn.lpstrTitle = _T("Select the image");

if( objFileDialog.DoModal() == IDOK)
{
m_csPath = objFileDialog.GetPathName();
if( !m_csPath.IsEmpty() )
{
CImage img;
img.Load( m_csPath );

if( !img.IsNull() )
{
//Invalidate();
CRect rect;
GetDlgItem( IDC_STATIC_PIC )->GetWindowRect( &rect );
ScreenToClient( rect );
InvalidateRect( rect, FALSE);
}
}
}
}

Downloading and writing binary file

Step1:

call GetFTPFile("http://www.speedace.info.jpg");

In the GetFTPFile function

void GetFTPFile(CString csPath)
{
CInternetSession csiSession;
DWORD dwServiceType = 0;
CString sServerName, sObject,csData;

INTERNET_PORT nPort; CString csTemp;

CString sGetFromURL; //( _T("") );

sGetFromURL =csQuery;

if ( !AfxParseURL ( sGetFromURL, dwServiceType, sServerName, sObject, nPort ) )
throw;

CHttpConnection* pHTTPServer = NULL;
pHTTPServer = csiSession.GetHttpConnection ( sServerName, nPort );
CHttpFile* pFile = NULL;
pFile = pHTTPServer->OpenRequest ( CHttpConnection::HTTP_VERB_GET, sObject, NULL, 1, NULL, NULL, INTERNET_FLAG_RELOAD );
pFile->SendRequest();
TCHAR sRaw [1024];
memset(sRaw,0,1024);
long lt = 0;
CFile fil;
CFileException fe;
int n = fil.Open("d:\\sen.jpg", CFile::modeWrite || CFile::typeBinary ,&fe );
while ( pFile->Read ( sRaw, 1024 ) )
{
fil.Write(sRaw,1024);
memset(sRaw,0,1024);
}

fil.Close();

pFile->Close();

pHTTPServer->Close();

}

Always dialog as top most window

In the dialog properties change system modal to TRUE

Round edged dialog

In dialog .h file

Add member variable

CRgn m_rgn;

In .cpp file in OnInitDialog function insert
this code after the line .....Dialog::OnInitDialog();
-------------------------------------------------------
CRect rect;
GetClientRect(rect);
m_rgn.CreateRoundRectRgn( rect.left, rect.top, rect.right, rect.bottom, 5,5);
SetWindowRgn((HRGN)m_rgn, TRUE);
--------------------------------------------------------

Datatype convertion

integer to TCHAR array
----------------
TCHAR szStatic[32];
wsprintf(szStatic,_T("%d min(s)"),dwValue);

integer to char array
----------------
char szStatic[32];
sprintf(szStatic,"%d min(s)",dwValue);


CString to char *
----------------
char *szPic=new char[csPic.GetLength()+1] ;
sprintf(szPic,"%S",csPic.GetBuffer(0));

char array to cstring
----------------
char strString[] = "this is a char string";
CString cstring;
cstring = CString( strString );

char array to STL string
---------------------
char buffer[] = "senthil";
string sValue;
sValue.assign((char*)buffer);

LPCSTR to LPCTSTR ( anscii to unicode conversion )
----------------------------------------
LPCSTR psz="senthil";
LPCTSTR m_ptsz=NULL;

const int size = MultiByteToWideChar(CP_ACP, 0, psz, -1, NULL, 0);

if (size == 0) {

ASSERT(!_T("Function \"MultiByteToWideChar\" failed."));
}
m_ptsz = new WCHAR [(sizeof(WCHAR)*size)];
VERIFY(MultiByteToWideChar(CP_ACP, 0, psz, -1, (LPWSTR)m_ptsz, size) != 0);
delete [] m_ptsz;
m_ptsz = NULL;

Dll creation

creation of win32 dll

step 1:
create a win32 project with the name Sampledll

step 2:
A Sampledll.cpp file will be created with Dllmain function
BOOL APIENTRY DllMain(HMODULE hModule,DWORD reason_for_call,LPVOID lpReserved )
{
return TRUE;
}

step 3:
create a .h file named Sampledll.h and expotable APIs and callback function

#ifdef VISUALIMITSINTERFACE_EXPORTS // in the project settings,c++ ->preprocessor we can find this macro
#define MY_DLL DLLEXPORT
#else
#define MY_DLL DLLIMPORT
#endif

typedef void (*fun2)(int, int);
extern "C" MY_DLL int fun1( int a , int b);
extern "C" MY_DLL int fun3(char* sz1,fun2 fpfun2);

step 4:

In the Sampledll.cpp , write exportable function defintions
extern "C" DLLEXPORT int fun1( int a , int b){... ..return n;}
extern "C" DLLEXPORT int fun3(char* sz1,fun2 fpfun2){....fpfun2(i,n); // callback function that used to call a function in Exe
}

step 5:
create a Exe application

Include the file Sampledll.h

Instead of .. extern "C" MY_DLL int fun1( int a , int b);
, we can add the following lines
typedef void (*pfnfun2)(int, int); // callback function
typedef int (*pfnfun1)(char* ,char* );typedef int (*pfnfun3)(char*,pfnfun2);

step 6:

In the SampleDlg.h file declare this

pfnfun1 fun1;
pfnfun3 fun3;

step 7:

In the SampleDlg.cpp file add this callback function

void SampleCallBack(int n, int y)
{
return;
}

In a function call this API to set callback function for the dll

void CVisuaLimitsServerDlg::OnBnClickedBtnTransfer()
{
fun3(szResult,&SampleCallBack);
}

Using Loadlibrary we can load the dll

m_hInstance = LoadLibrary(L"Sampledll.dll");

if (m_hInstance)
{
fun1 = (pfnfun1) GetProcAddress (m_hInstance, "fun1");
fun3 = (pfnfun3) GetProcAddress (m_hInstance, "fun3");
}