再试一次 - 将ascii命令字符串写入虚拟打印机 [英] try again - Writing ascii command strings to a virtual printer

问题描述

我有一个应用程序需要从文本文件中读取一些ascii命令，然后一次将它们输出到虚拟打印机，这是一个USB并行端口。该设备名为Generic / Text Only，使用名为USB Printing Support的驱动程序通过名为USB001的端口进行访问。我可以使用带有上述信息的CreateDC，然后使用dc来绘制文本等，但它增加了一大堆开销。我可以使用任何纯文本方法吗？ （记得打印和LPrint吗？）万一你感兴趣，我必须一次写一行，因为虚拟设备的缓冲区非常有限。



任何帮助将不胜感激！



好​​的，也许太多的信息使问题蒙上阴影。让我重申一下吧！



我有一个MSVC ++ MFC应用程序需要将空终止的C风格字符串写入通过USB连接到并行端口设备的虚拟打印机。在名为USB001的端口上使用名为USB Printing Support的驱动程序，设备名称为Generic / text only。将字符串送到打印机的最佳方法是什么？



再次感谢您的期待！

I have an application that needs to read some ascii commands from a text file and then output them one line at a time to a virtual printer which is a USB parallel port. The device is named "Generic / Text Only" and it is accessed thru a port named "USB001" using a driver named "USB Printing Support". I can use CreateDC with the above info and then use the dc to draw text etc but it adds a whole bunch of overhead. Is there any plain text method that I can use? ( remember Print & LPrint??) Just in case you''re interested, I have to write one line at a time because the virtual device has a very limited buffer.

Any help will be appreciated!

OK, Maybe too much information clouded the question. Let me restate it!

I have a MSVC++ MFC application that needs to write null terminated C-style strings to a virtual printer attached via a USB to Parallel port device. The device name is "Generic / text only" using a driver named "USB Printing Support" on a port named "USB001". What is the best way to get the strings to the printer?

Thanks again for looking!

推荐答案

您可以尝试使用 CreateFile（）打开设备并写入：

You can try to use CreateFile() to open the device and write to it:

HANDLE hDevice = ::CreateFile(_T("\\\\.\\USB001"), 
    GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0);
if (INVALID_HANDLE_VALUE != hDevice)
{
    LPCSTR lpszTest = "Test";
    DWORD dwWritten = 0;
    ::WriteFile(hDevice, lpszTest, strlen(lpszTest), &dwWritten, NULL);
    ::CloseHandle(hDevice);
}

请注意，可能需要将设备名称更改为其他名称（_T（\\Device \\< name> ;）或长版本，如''usb＃vid ...& pid ..& ...& CLSID''）。如果你得到了正确的名字，这应该可行。

Note that it may be necessary to change the device name to something else (_T("\\Device\\<name>") or the the long version like ''usb#vid...&pid..&...&CLSID''). If you got the correct name, this should work.

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