www.pudn.com > 基于TWAIN接口程序.zip > TwainCpp.cpp
#include "stdafx.h"
#include "twaincpp.h"
/*
Constructor:
Parameters : HWND
Window to subclass
*/
CTwain::CTwain(HWND hWnd)
{
m_hTwainDLL = NULL;
m_pDSMProc = NULL;
m_bSourceSelected = FALSE;
m_bDSOpen = m_bDSMOpen = FALSE;
m_bSourceEnabled = FALSE;
m_bModalUI = TRUE;
m_nImageCount = TWCPP_ANYCOUNT;
if(hWnd)
{
InitTwain(hWnd);
}
}
CTwain::~CTwain()
{
ReleaseTwain();
}
/*
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 CTwain::ReleaseTwain()
{
if(IsValidDriver())
{
CloseDSM();
FreeLibrary(m_hTwainDLL);
m_hTwainDLL = NULL;
m_pDSMProc = NULL;
}
}
/*
Returns true if a valid driver has been loaded
*/
BOOL CTwain::IsValidDriver() const
{
return (m_hTwainDLL && m_pDSMProc);
}
/*
Entry point into Twain. For a complete description of this
routine please refer to the Twain specification 1.8
*/
BOOL CTwain::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_SUCCESS)
{
(*m_pDSMProc)(pOrigin,pDest,DG_CONTROL,DAT_STATUS,MSG_GET,&m_Status);
}
return (ret_val == TWRC_SUCCESS);
}
else
{
m_returnCode = TWRC_FAILURE;
return FALSE;
}
}
/*
This function should ideally be overridden in the derived class . If only a
few fields need to be updated , call CTawin::GetIdentity first in your
derived class
*/
void CTwain::GetIdentity()
{
// Expects all the fields in m_AppId to be set except for the id field.
m_AppId.Id = 0; // Initialize to 0 (Source Manager
// will assign real value)
m_AppId.Version.MajorNum = 3; //Your app's version number
m_AppId.Version.MinorNum = 5;
m_AppId.Version.Language = TWLG_USA;
m_AppId.Version.Country = TWCY_USA;
strcpy (m_AppId.Version.Info, "3.5");
m_AppId.ProtocolMajor = TWON_PROTOCOLMAJOR;
m_AppId.ProtocolMinor = TWON_PROTOCOLMINOR;
m_AppId.SupportedGroups = DG_IMAGE | DG_CONTROL;
strcpy (m_AppId.Manufacturer, "MICSS");
strcpy (m_AppId.ProductFamily, "Generic");
strcpy (m_AppId.ProductName, "Twain Test");
}
/*
Called to display a dialog box to select the Twain source to use.
This can be overridden if a list of all sources is available
to the application. These sources can be enumerated by Twain.
it is not yet supportted by CTwain.
*/
BOOL CTwain::SelectSource()
{
memset(&m_Source,0,sizeof(m_Source));
if(!SourceSelected())
{
SelectDefaultSource();
}
if(CallTwainProc(&m_AppId,NULL,DG_CONTROL,DAT_IDENTITY,MSG_USERSELECT,&m_Source))
{
m_bSourceSelected = TRUE;
}
return m_bSourceSelected;
}
/*
Called to select the default source
*/
BOOL CTwain::SelectDefaultSource()
{
m_bSourceSelected = CallTwainProc(&m_AppId,NULL,DG_CONTROL,DAT_IDENTITY,MSG_GETDEFAULT,&m_Source);
return m_bSourceSelected;
}
/*
Closes the Data Source
*/
void CTwain::CloseDS()
{
if(DSOpen())
{
DisableSource();
CallTwainProc(&m_AppId,NULL,DG_CONTROL,DAT_IDENTITY,MSG_CLOSEDS,(TW_MEMREF)&m_Source);
m_bDSOpen = FALSE;
}
}
/*
Closes the Data Source Manager
*/
void CTwain::CloseDSM()
{
if(DSMOpen())
{
CloseDS();
CallTwainProc(&m_AppId,NULL,DG_CONTROL,DAT_PARENT,MSG_CLOSEDSM,(TW_MEMREF)&m_hMessageWnd);
m_bDSMOpen = FALSE;
}
}
/*
Returns true if the Data Source Manager is Open
*/
BOOL CTwain::DSMOpen() const
{
return IsValidDriver() && m_bDSMOpen;
}
/*
Returns true if the Data Source is Open
*/
BOOL CTwain::DSOpen() const
{
return IsValidDriver() && DSMOpen() && m_bDSOpen;
}
/*
Opens a Data Source supplied as the input parameter
*/
BOOL CTwain::OpenSource(TW_IDENTITY *pSource)
{
if(pSource)
{
m_Source = *pSource;
}
if(DSMOpen())
{
if(!SourceSelected())
{
SelectDefaultSource();
}
m_bDSOpen = CallTwainProc(&m_AppId,NULL,DG_CONTROL,DAT_IDENTITY,MSG_OPENDS,(TW_MEMREF)&m_Source);
}
return DSOpen();
}
/*
Should be called from the main message loop of the application. Can always be called,
it will not process the message unless a scan is in progress.
*/
BOOL CTwain::ProcessMessage(MSG msg)
{
if(SourceEnabled())
{
TW_EVENT twEvent;
twEvent.pEvent = (TW_MEMREF)&msg;
twEvent.TWMessage = MSG_NULL;
CallTwainProc(&m_AppId,&m_Source,DG_CONTROL,DAT_EVENT,MSG_PROCESSEVENT,(TW_MEMREF)&twEvent);
if(GetRC() != TWRC_NOTDSEVENT)
{
TranslateMessage(twEvent);
}
return FALSE;
}
return FALSE;
}
/*
Queries the capability of the Twain Data Source
*/
BOOL CTwain::GetCapability(TW_CAPABILITY& twCap,TW_UINT16 cap,TW_UINT16 conType)
{
if(DSOpen())
{
twCap.Cap = cap;
twCap.ConType = conType;
twCap.hContainer = NULL;
if(CallTwainProc(&m_AppId,&m_Source,DG_CONTROL,DAT_CAPABILITY,MSG_GET,(TW_MEMREF)&twCap))
{
return TRUE;
}
}
return FALSE;
}
/*
Queries the capability of the Twain Data Source
*/
BOOL CTwain::GetCapability(TW_UINT16 cap,TW_UINT32& value)
{
TW_CAPABILITY twCap;
if(GetCapability(twCap,cap))
{
pTW_ONEVALUE pVal;
pVal = (pTW_ONEVALUE )GlobalLock(twCap.hContainer);
if(pVal)
{
value = pVal->Item;
GlobalUnlock(pVal);
GlobalFree(twCap.hContainer);
return TRUE;
}
}
return FALSE;
}
/*
Sets the capability of the Twain Data Source
*/
BOOL CTwain::SetCapability(TW_UINT16 cap,TW_UINT16 value,BOOL sign)
{
if(DSOpen())
{
TW_CAPABILITY twCap;
pTW_ONEVALUE pVal;
BOOL ret_value = FALSE;
twCap.Cap = cap;
twCap.ConType = TWON_ONEVALUE;
twCap.hContainer = GlobalAlloc(GHND,sizeof(TW_ONEVALUE));
if(twCap.hContainer)
{
pVal = (pTW_ONEVALUE)GlobalLock(twCap.hContainer);
pVal->ItemType = sign ? TWTY_INT16 : TWTY_UINT16;
pVal->Item = (TW_UINT32)value;
GlobalUnlock(twCap.hContainer);
ret_value = SetCapability(twCap);
GlobalFree(twCap.hContainer);
}
return ret_value;
}
return FALSE;
}
/*
Sets the capability of the Twain Data Source
*/
BOOL CTwain::SetCapability(TW_CAPABILITY& cap)
{
if(DSOpen())
{
return CallTwainProc(&m_AppId,&m_Source,DG_CONTROL,DAT_CAPABILITY,MSG_SET,(TW_MEMREF)&cap);
}
return FALSE;
}
/*
Sets the number of images which can be accpeted by the application at one time
*/
BOOL CTwain::SetImageCount(TW_INT16 nCount)
{
if(SetCapability(CAP_XFERCOUNT,(TW_UINT16)nCount,TRUE))
{
m_nImageCount = nCount;
return TRUE;
}
else
{
if(GetRC() == TWRC_CHECKSTATUS)
{
TW_UINT32 count;
if(GetCapability(CAP_XFERCOUNT,count))
{
nCount = (TW_INT16)count;
if(SetCapability(CAP_XFERCOUNT,nCount))
{
m_nImageCount = nCount;
return TRUE;
}
}
}
}
return FALSE;
}
/*
Called to enable the Twain Acquire Dialog. This too can be
overridden but is a helluva job .
*/
BOOL CTwain::EnableSource(BOOL showUI)
{
if(DSOpen() && !SourceEnabled())
{
TW_USERINTERFACE twUI;
twUI.ShowUI = showUI;
twUI.hParent = (TW_HANDLE)m_hMessageWnd;
if(CallTwainProc(&m_AppId,&m_Source,DG_CONTROL,DAT_USERINTERFACE,MSG_ENABLEDS,(TW_MEMREF)&twUI))
{
m_bSourceEnabled = TRUE;
m_bModalUI = twUI.ModalUI;
}
else
{
m_bSourceEnabled = FALSE;
m_bModalUI = TRUE;
}
return m_bSourceEnabled;
}
return FALSE;
}
/*
Called to acquire images from the source. parameter numImages i the
numberof images that you an handle concurrently
*/
BOOL CTwain::Acquire(int numImages)
{
if(DSOpen() || OpenSource())
{
if(SetImageCount(numImages))
{
if(EnableSource())
{
return TRUE;
}
}
}
return FALSE;
}
/*
Called to disable the source.
*/
BOOL CTwain::DisableSource()
{
if(SourceEnabled())
{
TW_USERINTERFACE twUI;
if(CallTwainProc(&m_AppId,&m_Source,DG_CONTROL,DAT_USERINTERFACE,MSG_DISABLEDS,&twUI))
{
m_bSourceEnabled = FALSE;
return TRUE;
}
}
return FALSE;
}
/*
Called by ProcessMessage to Translate a TWAIN message
*/
void CTwain::TranslateMessage(TW_EVENT& twEvent)
{
switch(twEvent.TWMessage)
{
case MSG_XFERREADY:
TransferImage();
break;
case MSG_CLOSEDSREQ:
if(CanClose())
{
CloseDS();
}
break;
}
}
/*
Gets Imageinfo for an image which is about to be transferred.
*/
BOOL CTwain::GetImageInfo(TW_IMAGEINFO& info)
{
if(SourceEnabled())
{
return CallTwainProc(&m_AppId,&m_Source,DG_IMAGE,DAT_IMAGEINFO,MSG_GET,(TW_MEMREF)&info);
}
return FALSE;
}
/*
Trasnfers the image or cancels the transfer depending on the state of the
TWAIN system
*/
void CTwain::TransferImage()
{
TW_IMAGEINFO info;
BOOL bContinue=TRUE;
while(bContinue)
{
if(GetImageInfo(info))
{
int permission;
permission = ShouldTransfer(info);
switch(permission)
{
case TWCPP_CANCELTHIS:
bContinue=EndTransfer();
break;
case TWCPP_CANCELALL:
CancelTransfer();
bContinue=FALSE;
break;
case TWCPP_DOTRANSFER:
bContinue=GetImage(info);
break;
}
}
}
}
/*
Ends the current transfer.
Returns TRUE if the more images are pending
*/
BOOL CTwain::EndTransfer()
{
TW_PENDINGXFERS twPend;
if(CallTwainProc(&m_AppId,&m_Source,DG_CONTROL,DAT_PENDINGXFERS,MSG_ENDXFER,(TW_MEMREF)&twPend))
{
return twPend.Count != 0;
}
return FALSE;
}
/*
Aborts all transfers
*/
void CTwain::CancelTransfer()
{
TW_PENDINGXFERS twPend;
CallTwainProc(&m_AppId,&m_Source,DG_CONTROL,DAT_PENDINGXFERS,MSG_RESET,(TW_MEMREF)&twPend);
}
/*
Calls TWAIN to actually get the image
*/
BOOL CTwain::GetImage(TW_IMAGEINFO& info)
{
HANDLE hBitmap;
CallTwainProc(&m_AppId,&m_Source,DG_IMAGE,DAT_IMAGENATIVEXFER,MSG_GET,&hBitmap);
switch(m_returnCode)
{
case TWRC_XFERDONE:
CopyImage(hBitmap,info);
break;
case TWRC_CANCEL:
break;
case TWRC_FAILURE:
CancelTransfer();
return FALSE;
}
GlobalFree(hBitmap);
return EndTransfer();
}