在Windows上打印不起作用

目前我正在使用以下代码 here :

BOOL RawDataToPrinter(LPTSTR szPrinterName, LPBYTE lpData, DWORD dwCount)
{
    BOOL     bStatus = FALSE;
    HANDLE     hPrinter = NULL;
    DOC_INFO_1 DocInfo;
    DWORD      dwJob = 0L;
    DWORD      dwBytesWritten = 0L;

    bStatus = OpenPrinter(szPrinterName, &hPrinter, NULL);

    if (bStatus) {
        // Fill in the structure with info about this "document." 
        DocInfo.pDocName = (LPTSTR)_T("My Document");
        DocInfo.pOutputFile = NULL;
        DocInfo.pDatatype = (LPTSTR)_T("RAW");

        // Inform the spooler the document is beginning. 
        dwJob = StartDocPrinter(hPrinter, 1, (LPBYTE)&DocInfo);
        if (dwJob > 0) {
            // Start a page. 
            bStatus = StartPagePrinter(hPrinter);

            if (bStatus) {
                // Send the data to the printer. 
                bStatus = WritePrinter(hPrinter, lpData, dwCount, &dwBytesWritten);
                EndPagePrinter(hPrinter);
            }
            // Inform the spooler that the document is ending. 
            EndDocPrinter(hPrinter);
        }
        // Close the printer handle. 
        ClosePrinter(hPrinter);

        std::cout << GetLastError() << std::endl;
    }
    // Check to see if correct number of bytes were written. 
    if (!bStatus || (dwBytesWritten != dwCount)) {
        bStatus = FALSE;
    }
    else {
        bStatus = TRUE;
    }
    return bStatus;
}

std::string str = "Hello World";
BOOL blubb = RawDataToPrinter((LPTSTR)_T("PRINTER_NAME"), (LPBYTE) str.c_str(), str.size());

我遇到的问题是,打印作业在打印机的打印队列中显示了几毫秒(刚好可以看到),但他什么都不打印。

有人知道我做错了什么吗?