/*
Initializes TWAIN interface . Is already called from the constructor.
It should be called again if ReleaseTwain is called.
hWnd is the window which has to subclassed in order to recieve
Twain messaged. Normally - this would be your main application window.
*/
BOOL CTwain::InitTwain(HWND hWnd)
{
char libName[512];
if(IsValidDriver())
{
return TRUE;
}
memset(&m_AppId,0,sizeof(m_AppId));
if(!IsWindow(hWnd))
{
return FALSE;
}
m_hMessageWnd = hWnd;
strcpy(libName,"TWAIN_32.DLL");
m_hTwainDLL = LoadLibrary(libName);
if(m_hTwainDLL != NULL)
{
if(!(m_pDSMProc = (DSMENTRYPROC)GetProcAddress(m_hTwainDLL,MAKEINTRESOURCE(1))))
{
FreeLibrary(m_hTwainDLL);
m_hTwainDLL = NULL;
}
}
if(IsValidDriver())
{
GetIdentity();
m_bDSMOpen= CallTwainProc(&m_AppId,NULL,DG_CONTROL,DAT_PARENT,MSG_OPENDSM,(TW_MEMREF)&m_hMessageWnd);
return TRUE;
}
else
{
return FALSE;
}
}
/** Releases the twain interface . Need not be called unless you
want to specifically shut it down.
*/
void TwainIface::ReleaseTwain()
{
if(IsValidDriver())
{
CloseDSM();
FreeLibrary(m_hTwainDLL);
m_hTwainDLL = NULL;
m_pDSMProc = NULL;
}
}
/** Entry point into Twain. For a complete description of this
routine please refer to the Twain specification 1.8
*/
bool TwainIface::CallTwainProc(pTW_IDENTITY pOrigin, pTW_IDENTITY pDest,
TW_UINT32 DG, TW_UINT16 DAT, TW_UINT16 MSG, TW_MEMREF pData)
{
if(IsValidDriver())
{
USHORT ret_val;
ret_val = (*m_pDSMProc)(pOrigin, pDest, DG, DAT, MSG, pData);
m_returnCode = ret_val;
if(ret_val == TWRC_FAILURE)
{
(*m_pDSMProc)(pOrigin, pDest, DG_CONTROL, DAT_STATUS, MSG_GET, &m_Status);
}
return (ret_val == TWRC_SUCCESS);
}
else
{
m_returnCode = TWRC_FAILURE;
return false;
}
}
int EVOpenDlg::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
if (CDialog::OnCreate(lpCreateStruct) == -1)
return -1;
// TODO: 在此添加您专用的创建代码
InitTwain(m_hWnd);
if(!IsValidDriver())
{
AfxMessageBox("Unable to load Twain Driver.");
}
SetTimer(1,1000,NULL);
dlgArea = new EVAreaDlg;
dlgArea->Create(IDD_AREA,this);
dlgArea->pDlg = this;
dlgArea->uEditID = IDC_NEWEDIT4;
dlgArea->ShowWindow(SW_HIDE);
dlgArea->m_szArea=&m_szArea;
return 0;
}
/** Returns true if the Data Source is Open
*/
bool TwainIface::DSOpen() const
{
return IsValidDriver() && DSMOpen() && m_bDSOpen;
}
/*
Returns true if the Data Source is Open
*/
BOOL CTwain::DSOpen() const
{
return IsValidDriver() && DSMOpen() && m_bDSOpen;
}
bool QTwain::isValidDriver() const
{
return (IsValidDriver() == true);
} // !isValidDriver()
