如何在程序中指定当前默认打印机打印指定的文档

各位大虾，我刚刚做了一个虚拟打印机，可以将打印内容输出成为BMP文件．但我的老板要求必须在程序里由用户来选择某个文档，然后在程序里自动将其发送给当前默认打印机进行打印．晕．．．．
请问有什么方法可以实现这个问题呢？

　　　不胜感激！！！！！！！！！

没有人顶，自己顶一下先．
诸位大虾，俺在这里跪求了，不愿意告诉我给个思路也行阿

意思不太明白。
你的虚拟打印机又是起什么功能？

给一段取得当前缺省打印机的代码，看有没有用。

typedef BOOL (WINAPI *WINAPI_GetDefaultPrinter)(LPTSTR pszBuffer, LPDWORD pcchBuffer);

BOOL DPGetDefaultPrinter(LPTSTR pPrinterName, LPDWORD pdwBufferSize)
{

BOOL bFlag;
OSVERSIONINFO osv;
TCHAR cBuffer[MAX_PATH]="";
PRINTER_INFO_2 *ppi2 = NULL;
DWORD dwNeeded = 0;
DWORD dwReturned = 0;
static WINAPI_GetDefaultPrinter procGetDefaultPrinter=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)
{
EnumPrinters(PRINTER_ENUM_DEFAULT, NULL, 2, NULL, 0, &dwNeeded, &dwReturned);
if (dwNeeded == 0)
return FALSE;
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 ((DWORD)lstrlen(ppi2->pPrinterName) >= *pdwBufferSize)
{
*pdwBufferSize = (DWORD)lstrlen(ppi2->pPrinterName) + 1;
GlobalFree(ppi2);
return FALSE;
}

lstrcpy(pPrinterName, ppi2->pPrinterName);
*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(WINVER >= 0x0500)
if (osv.dwMajorVersion >= 5) // Windows 2000 or later
{
if (procGetDefaultPrinter==NULL)
{
HMODULE hDll=NULL;

hDll=GetModuleHandle("WINSPOOL.DRV");
if (hDll==NULL)
return FALSE;
#ifdef UNICODE
procGetDefaultPrinter = (WINAPI_GetDefaultPrinter)GetProcAddress(hDll, _T("GetDefaultPrinterW"));
#else
procGetDefaultPrinter = (WINAPI_GetDefaultPrinter)GetProcAddress(hDll, "GetDefaultPrinterA");
#endif
if (procGetDefaultPrinter==NULL)
return FALSE;
}
bFlag = procGetDefaultPrinter(pPrinterName, pdwBufferSize);
if (!bFlag)
return FALSE;
}
else // NT4.0 or earlier
//#endif
{
// Retrieve the default string from Win.ini (the registry).
// String will be in form "printername,drivername,portname".
if (GetProfileString("windows", "device", ",,,", cBuffer, MAX_PATH) <= 0)
return FALSE;

// Printer name precedes first "," character...
strtok(cBuffer, ",");

// If given buffer 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 min required buffer size...
*pdwBufferSize = (DWORD)lstrlen(cBuffer) + 1;
}
}

// Cleanup...
if (ppi2)
GlobalFree(ppi2);

return TRUE;
}

谢谢二楼的回复，我已经解决问题了．是用ShellExecute函数将文档发送到系统当前默认打印机打印的
．呵呵