用 C# 实现 OPOS 设备

Implement OPOS Device in C#

提问by jonathanpeppers

For some interop with a legacy POS application, I was wondering if it was possible to implement a phony OPOS device in C#.

对于与传统 POS 应用程序的一些互操作，我想知道是否可以在 C# 中实现一个虚假的 OPOS 设备。

Basically I would implement a phony keyboard that took web requests and passed on key presses to the legacy application.

基本上我会实现一个假键盘，它接受网络请求并将按键传递给遗留应用程序。

Does anyone know if this is possible or where to get documentation? I figured OPOS just called COM objects which are configured by registry keys. All of which should be implementable in C#.

有谁知道这是否可行或从哪里获得文档？我认为 OPOS 只是调用了由注册表项配置的 COM 对象。所有这些都应该可以在 C# 中实现。

采纳答案by Joe

Yes it's certainly possible.

是的，这当然是可能的。

You can develop an OPOS SO (Service Object) which implements the COM interface expected by OPOS in C#. This can then implement the API in any way you want.

您可以开发一个 OPOS SO（服务对象），它在 C# 中实现 OPOS 所期望的 COM 接口。然后，这可以以您想要的任何方式实现 API。

I suggest you download Curtiss Monroe's OPOS Common Control Objects from http://monroecs.com/oposccos.htm.

我建议您从http://monroecs.com/oposccos.htm下载 Curtiss Monroe 的 OPOS Common Control Objects 。

This will give you the type libraries you need to implement for your Service object(s), and probably has some links to the OPOS documentation. NB I think OPOS uses late-binding so you will need to implement a dual interface.

这将为您提供需要为服务对象实现的类型库，并且可能有一些指向 OPOS 文档的链接。注意，我认为 OPOS 使用后期绑定，因此您需要实现双接口。

A caveat: IMHO OPOS is technically a horrible API, designed by a committee peripheral vendors to expose the capabilities of their peripherals rather than to provide a useful abstraction for POS application developers.

警告：恕我直言，OPOS 在技术上是一个可怕的 API，由委员会外围设备供应商设计，以公开其外围设备的功能，而不是为 POS 应用程序开发人员提供有用的抽象。

A particularly striking example of this is the so-called ToneIndicator device, which exposes the capabilities of a tone generator in a Fujitsu keyboard to sound a repeated sequence of two tones of different pitch and volume.

一个特别引人注目的例子是所谓的 ToneIndicator 设备，它展示了富士通键盘中音调发生器的功能，可以发出不同音高和音量的两种音调的重复序列。

UPDATE

更新

I have implemented OPOS Service Objects before, but it's been a long time. Here's some more info to get you started on a POSKeyboard SO.

我之前已经实现了 OPOS 服务对象，但已经很长时间了。这里有更多信息可以帮助您开始使用 POSKeyboard SO。

• The Control object (CO) will load your Service Object (SO) using late-binding. So in fact there is no COM IID or type library that you implement. Instead you need to implement all the required methods and events defined in the appropriate version of the OPOS specs (e.g. one of the docs on this page: http://monroecs.com/oposreleases.htm). The info below is based on the 1.6 Control Programer's Guide (CPG) linked on this page.

• Chapter 2 of the CPG describes what you need to implement. Note that OPOS uses a weird method for getting/setting properties. Whereas the Control Object (CO) exposes properties with sensible names (e.g. DeviceEnabled, DeviceName, DeviceDescription), these all call into the same methods GetPropertyString (for string properties) or GetPropertyNumber (for integer properties), passing an integer "property index" as an argument that defines which property is to be retrieved. The "property indexes" are all defined in header files supplied with the OPOS standard.

• From a quick glance at the CCO PosKeyboard source, the method names you need to implement are listed in s_SOMethodNames in the source file POSKeyboardImpl.cpp.

• The registry entries you need to set up are defined in the OPOS Application Programmer's Guide (APG) appendix "OPOS Registry Usage". In your case you will need to create a registry key HKLM\OleForRetail\ServiceOPOS\POSKeyboard\DefaultPOSKeyboard (where DefaultPOSKeyboard is the device name you are passing the Open method). This registry key needs to have a default value which is the ProgId of your SO class. You can also store other values there (e.g. configuration information used by your SO).

• 控制对象 (CO) 将使用后期绑定加载您的服务对象 (SO)。所以实际上没有您实现的 COM IID 或类型库。相反，您需要实现 OPOS 规范的适当版本中定义的所有必需方法和事件（例如，此页面上的文档之一：http: //monroecs.com/oposreleases.htm）。以下信息基于此页面上链接的 1.6 控制程序员指南 (CPG)。

• CPG 的第 2 章描述了您需要实现的内容。请注意，OPOS 使用一种奇怪的方法来获取/设置属性。而控制对象 (CO) 公开具有合理名称的属性（例如 DeviceEnabled、DeviceName、DeviceDescription），这些都调用相同的方法 GetPropertyString（对于字符串属性）或 GetPropertyNumber（对于整数属性），将整数“属性索引”作为定义要检索哪个属性的参数。“属性索引”都在 OPOS 标准提供的头文件中定义。

• 快速浏览一下 CCO PosKeyboard 源代码，您需要实现的方法名称列在源文件 POSKeyboardImpl.cpp 中的 s_SOMethodNames 中。

• 您需要设置的注册表项在 OPOS 应用程序程序员指南 (APG) 附录“OPOS 注册表用法”中定义。在您的情况下，您需要创建一个注册表项 HKLM\OleForRetail\ServiceOPOS\POSKeyboard\DefaultPOSKeyboard（其中 DefaultPOSKeyboard 是您传递 Open 方法的设备名称）。此注册表项需要有一个默认值，即您的 SO 类的 ProgId。您还可以在那里存储其他值（例如，您的 SO 使用的配置信息）。

Good luck with this - it will be a painful process with plenty of WTF's.

祝你好运 - 这将是一个痛苦的过程，有很多 WTF。