الطابعة الافتراضية في C++ غير المُدارة
https://stackoverflow.com/questions/104844
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أنا أبحث عن طريقة للعثور على اسم الطابعة الافتراضية لنظام التشغيل Windows باستخدام لغة C++ غير المُدارة (وجدت الكثير من أمثلة .NET، ولكن لم تحقق أي نجاح بدون إدارة).شكرًا.
المحلول
ما يلي يعمل بشكل رائع للطباعة باستخدام win32api من C++
char szPrinterName[255];
unsigned long lPrinterNameLength;
GetDefaultPrinter( szPrinterName, &lPrinterNameLength );
HDC hPrinterDC;
hPrinterDC = CreateDC("WINSPOOL\0", szPrinterName, NULL, NULL);
في المستقبل، بدلًا من البحث في Google عن "غير مُدار"، حاول البحث في Google عن "win32 /subject/" أو "win32 api /subject/"
نصائح أخرى
فيما يلي كيفية الحصول على قائمة بالطابعات الحالية والطابعات الافتراضية إذا كان هناك واحدة تم تعيينها كطابعة افتراضية.
لاحظ أيضًا:يعد الحصول على صفر لطول اسم الطابعة الافتراضي صالحًا إذا لم يكن لدى المستخدم طابعات أو لم يقم بتعيين واحدة كطابعة افتراضية.
يجب أيضًا دعم القدرة على التعامل مع أسماء الطابعة الطويلة، لذا فإن استدعاء GetDefaultPrinter باستخدام NULL كمؤشر مخزن مؤقت أولاً سيعيد طول الاسم ثم يمكنك تخصيص مخزن مؤقت للاسم كبير بما يكفي للاحتفاظ بالاسم.
DWORD numprinters;
DWORD defprinter=0;
DWORD dwSizeNeeded=0;
DWORD dwItem;
LPPRINTER_INFO_2 printerinfo = NULL;
// Get buffer size
EnumPrinters ( PRINTER_ENUM_LOCAL | PRINTER_ENUM_CONNECTIONS , NULL, 2, NULL, 0, &dwSizeNeeded, &numprinters );
// allocate memory
//printerinfo = (LPPRINTER_INFO_2)HeapAlloc ( GetProcessHeap (), HEAP_ZERO_MEMORY, dwSizeNeeded );
printerinfo = (LPPRINTER_INFO_2)new char[dwSizeNeeded];
if ( EnumPrinters ( PRINTER_ENUM_LOCAL | PRINTER_ENUM_CONNECTIONS, // what to enumerate
NULL, // printer name (NULL for all)
2, // level
(LPBYTE)printerinfo, // buffer
dwSizeNeeded, // size of buffer
&dwSizeNeeded, // returns size
&numprinters // return num. items
) == 0 )
{
numprinters=0;
}
{
DWORD size=0;
// Get the size of the default printer name.
GetDefaultPrinter(NULL, &size);
if(size)
{
// Allocate a buffer large enough to hold the printer name.
TCHAR* buffer = new TCHAR[size];
// Get the printer name.
GetDefaultPrinter(buffer, &size);
for ( dwItem = 0; dwItem < numprinters; dwItem++ )
{
if(!strcmp(buffer,printerinfo[dwItem].pPrinterName))
defprinter=dwItem;
}
delete buffer;
}
}
كيفية استرداد وتعيين الطابعة الافتراضية في نظام التشغيل Windows:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;246772
رمز من مقالة غير متوفرة الآن:
// You are explicitly linking to GetDefaultPrinter because linking
// implicitly on Windows 95/98 or NT4 results in a runtime error.
// This block specifies which text version you explicitly link to.
#ifdef UNICODE
#define GETDEFAULTPRINTER "GetDefaultPrinterW"
#else
#define GETDEFAULTPRINTER "GetDefaultPrinterA"
#endif
// Size of internal buffer used to hold "printername,drivername,portname"
// string. You may have to increase this for huge strings.
#define MAXBUFFERSIZE 250
/*----------------------------------------------------------------*/
/* DPGetDefaultPrinter */
/* */
/* Parameters: */
/* pPrinterName: Buffer alloc'd by caller to hold printer name. */
/* pdwBufferSize: On input, ptr to size of pPrinterName. */
/* On output, min required size of pPrinterName. */
/* */
/* NOTE: You must include enough space for the NULL terminator! */
/* */
/* Returns: TRUE for success, FALSE for failure. */
/*----------------------------------------------------------------*/
BOOL DPGetDefaultPrinter(LPTSTR pPrinterName, LPDWORD pdwBufferSize)
{
BOOL bFlag;
OSVERSIONINFO osv;
TCHAR cBuffer[MAXBUFFERSIZE];
PRINTER_INFO_2 *ppi2 = NULL;
DWORD dwNeeded = 0;
DWORD dwReturned = 0;
HMODULE hWinSpool = NULL;
PROC fnGetDefaultPrinter = NULL;
// What version of Windows are you running?
osv.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
GetVersionEx(&osv);
// If Windows 95 or 98, use EnumPrinters.
if (osv.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS)
{
// The first EnumPrinters() tells you how big our buffer must
// be to hold ALL of PRINTER_INFO_2. Note that this will
// typically return FALSE. This only means that the buffer (the 4th
// parameter) was not filled in. You do not want it filled in here.
SetLastError(0);
bFlag = EnumPrinters(PRINTER_ENUM_DEFAULT, NULL, 2, NULL, 0, &dwNeeded, &dwReturned);
{
if ((GetLastError() != ERROR_INSUFFICIENT_BUFFER) || (dwNeeded == 0))
return FALSE;
}
// Allocate enough space for PRINTER_INFO_2.
ppi2 = (PRINTER_INFO_2 *)GlobalAlloc(GPTR, dwNeeded);
if (!ppi2)
return FALSE;
// The second EnumPrinters() will fill in all the current information.
bFlag = EnumPrinters(PRINTER_ENUM_DEFAULT, NULL, 2, (LPBYTE)ppi2, dwNeeded, &dwNeeded, &dwReturned);
if (!bFlag)
{
GlobalFree(ppi2);
return FALSE;
}
// If specified buffer is too small, set required size and fail.
if ((DWORD)lstrlen(ppi2->pPrinterName) >= *pdwBufferSize)
{
*pdwBufferSize = (DWORD)lstrlen(ppi2->pPrinterName) + 1;
GlobalFree(ppi2);
return FALSE;
}
// Copy printer name into passed-in buffer.
lstrcpy(pPrinterName, ppi2->pPrinterName);
// Set buffer size parameter to minimum required buffer size.
*pdwBufferSize = (DWORD)lstrlen(ppi2->pPrinterName) + 1;
}
// If Windows NT, use the GetDefaultPrinter API for Windows 2000,
// or GetProfileString for version 4.0 and earlier.
else if (osv.dwPlatformId == VER_PLATFORM_WIN32_NT)
{
if (osv.dwMajorVersion >= 5) // Windows 2000 or later (use explicit call)
{
hWinSpool = LoadLibrary("winspool.drv");
if (!hWinSpool)
return FALSE;
fnGetDefaultPrinter = GetProcAddress(hWinSpool, GETDEFAULTPRINTER);
if (!fnGetDefaultPrinter)
{
FreeLibrary(hWinSpool);
return FALSE;
}
bFlag = fnGetDefaultPrinter(pPrinterName, pdwBufferSize);
FreeLibrary(hWinSpool);
if (!bFlag)
return FALSE;
}
else // NT4.0 or earlier
{
// Retrieve the default string from Win.ini (the registry).
// String will be in form "printername,drivername,portname".
if (GetProfileString("windows", "device", ",,,", cBuffer, MAXBUFFERSIZE) <= 0)
return FALSE;
// Printer name precedes first "," character.
strtok(cBuffer, ",");
// If specified buffer is too small, set required size and fail.
if ((DWORD)lstrlen(cBuffer) >= *pdwBufferSize)
{
*pdwBufferSize = (DWORD)lstrlen(cBuffer) + 1;
return FALSE;
}
// Copy printer name into passed-in buffer.
lstrcpy(pPrinterName, cBuffer);
// Set buffer size parameter to minimum required buffer size.
*pdwBufferSize = (DWORD)lstrlen(cBuffer) + 1;
}
}
// Clean up.
if (ppi2)
GlobalFree(ppi2);
return TRUE;
}
#undef MAXBUFFERSIZE
#undef GETDEFAULTPRINTER
// You are explicitly linking to SetDefaultPrinter because implicitly
// linking on Windows 95/98 or NT4 results in a runtime error.
// This block specifies which text version you explicitly link to.
#ifdef UNICODE
#define SETDEFAULTPRINTER "SetDefaultPrinterW"
#else
#define SETDEFAULTPRINTER "SetDefaultPrinterA"
#endif
/*-----------------------------------------------------------------*/
/* DPSetDefaultPrinter */
/* */
/* Parameters: */
/* pPrinterName: Valid name of existing printer to make default. */
/* */
/* Returns: TRUE for success, FALSE for failure. */
/*-----------------------------------------------------------------*/
BOOL DPSetDefaultPrinter(LPTSTR pPrinterName)
{
BOOL bFlag;
OSVERSIONINFO osv;
DWORD dwNeeded = 0;
HANDLE hPrinter = NULL;
PRINTER_INFO_2 *ppi2 = NULL;
LPTSTR pBuffer = NULL;
LONG lResult;
HMODULE hWinSpool = NULL;
PROC fnSetDefaultPrinter = NULL;
// What version of Windows are you running?
osv.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
GetVersionEx(&osv);
if (!pPrinterName)
return FALSE;
// If Windows 95 or 98, use SetPrinter.
if (osv.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS)
{
// Open this printer so you can get information about it.
bFlag = OpenPrinter(pPrinterName, &hPrinter, NULL);
if (!bFlag || !hPrinter)
return FALSE;
// The first GetPrinter() tells you how big our buffer must
// be to hold ALL of PRINTER_INFO_2. Note that this will
// typically return FALSE. This only means that the buffer (the 3rd
// parameter) was not filled in. You do not want it filled in here.
SetLastError(0);
bFlag = GetPrinter(hPrinter, 2, 0, 0, &dwNeeded);
if (!bFlag)
{
if ((GetLastError() != ERROR_INSUFFICIENT_BUFFER) || (dwNeeded == 0))
{
ClosePrinter(hPrinter);
return FALSE;
}
}
// Allocate enough space for PRINTER_INFO_2.
ppi2 = (PRINTER_INFO_2 *)GlobalAlloc(GPTR, dwNeeded);
if (!ppi2)
{
ClosePrinter(hPrinter);
return FALSE;
}
// The second GetPrinter() will fill in all the current information
// so that all you have to do is modify what you are interested in.
bFlag = GetPrinter(hPrinter, 2, (LPBYTE)ppi2, dwNeeded, &dwNeeded);
if (!bFlag)
{
ClosePrinter(hPrinter);
GlobalFree(ppi2);
return FALSE;
}
// Set default printer attribute for this printer.
ppi2->Attributes |= PRINTER_ATTRIBUTE_DEFAULT;
bFlag = SetPrinter(hPrinter, 2, (LPBYTE)ppi2, 0);
if (!bFlag)
{
ClosePrinter(hPrinter);
GlobalFree(ppi2);
return FALSE;
}
// Tell all open programs that this change occurred.
// Allow each program 1 second to handle this message.
lResult = SendMessageTimeout(HWND_BROADCAST, WM_SETTINGCHANGE, 0L,
(LPARAM)(LPCTSTR)"windows", SMTO_NORMAL, 1000, NULL);
}
// If Windows NT, use the SetDefaultPrinter API for Windows 2000,
// or WriteProfileString for version 4.0 and earlier.
else if (osv.dwPlatformId == VER_PLATFORM_WIN32_NT)
{
if (osv.dwMajorVersion >= 5) // Windows 2000 or later (use explicit call)
{
hWinSpool = LoadLibrary("winspool.drv");
if (!hWinSpool)
return FALSE;
fnSetDefaultPrinter = GetProcAddress(hWinSpool, SETDEFAULTPRINTER);
if (!fnSetDefaultPrinter)
{
FreeLibrary(hWinSpool);
return FALSE;
}
bFlag = fnSetDefaultPrinter(pPrinterName);
FreeLibrary(hWinSpool);
if (!bFlag)
return FALSE;
}
else // NT4.0 or earlier
{
// Open this printer so you can get information about it.
bFlag = OpenPrinter(pPrinterName, &hPrinter, NULL);
if (!bFlag || !hPrinter)
return FALSE;
// The first GetPrinter() tells you how big our buffer must
// be to hold ALL of PRINTER_INFO_2. Note that this will
// typically return FALSE. This only means that the buffer (the 3rd
// parameter) was not filled in. You do not want it filled in here.
SetLastError(0);
bFlag = GetPrinter(hPrinter, 2, 0, 0, &dwNeeded);
if (!bFlag)
{
if ((GetLastError() != ERROR_INSUFFICIENT_BUFFER) || (dwNeeded == 0))
{
ClosePrinter(hPrinter);
return FALSE;
}
}
// Allocate enough space for PRINTER_INFO_2.
ppi2 = (PRINTER_INFO_2 *)GlobalAlloc(GPTR, dwNeeded);
if (!ppi2)
{
ClosePrinter(hPrinter);
return FALSE;
}
// The second GetPrinter() fills in all the current<BR/>
// information.
bFlag = GetPrinter(hPrinter, 2, (LPBYTE)ppi2, dwNeeded, &dwNeeded);
if ((!bFlag) || (!ppi2->pDriverName) || (!ppi2->pPortName))
{
ClosePrinter(hPrinter);
GlobalFree(ppi2);
return FALSE;
}
// Allocate buffer big enough for concatenated string.
// String will be in form "printername,drivername,portname".
pBuffer = (LPTSTR)GlobalAlloc(GPTR,
lstrlen(pPrinterName) +
lstrlen(ppi2->pDriverName) +
lstrlen(ppi2->pPortName) + 3);
if (!pBuffer)
{
ClosePrinter(hPrinter);
GlobalFree(ppi2);
return FALSE;
}
// Build string in form "printername,drivername,portname".
lstrcpy(pBuffer, pPrinterName); lstrcat(pBuffer, ",");
lstrcat(pBuffer, ppi2->pDriverName); lstrcat(pBuffer, ",");
lstrcat(pBuffer, ppi2->pPortName);
// Set the default printer in Win.ini and registry.
bFlag = WriteProfileString("windows", "device", pBuffer);
if (!bFlag)
{
ClosePrinter(hPrinter);
GlobalFree(ppi2);
GlobalFree(pBuffer);
return FALSE;
}
}
// Tell all open programs that this change occurred.
// Allow each app 1 second to handle this message.
lResult = SendMessageTimeout(HWND_BROADCAST, WM_SETTINGCHANGE, 0L, 0L,
SMTO_NORMAL, 1000, NULL);
}
// Clean up.
if (hPrinter)
ClosePrinter(hPrinter);
if (ppi2)
GlobalFree(ppi2);
if (pBuffer)
GlobalFree(pBuffer);
return TRUE;
}
#undef SETDEFAULTPRINTER
GetDefaultPrinter (MSDN) يجب أن تفعل الحيلة.سيؤدي ذلك إلى حصولك على الاسم لتمريره إلى CreateDC للطباعة.
C++ غير مُدار غير موجود (وC++ المُدار أصبح الآن C++/CLI)، إذا كنت تشير إلى C++، فإن استخدام غير مُدار كعلامة أمر محزن ...
لا تنتمي إلى StackOverflow
