Base Class DirectIO Method (POS for .NET v1.14 SDK Documentation)


The DirectIO method and the DirectIOEvent event are used to provide functionality to the application that is not otherwise supported by the standard Unified Point Of Service (UnifiedPOS) specification for a particular device type.

DirectIO Method

If a device has features that are not supported by the standard UnifiedPOS specification, a Service Object may implement a DirectIO method to give the application access to those features.

An example might be a LineDisplay device that supports multicolor output. Few, if any, LineDisplay-type devices support color output, but an independent hardware vendor (IHV) might produce such a device and want to have the new features available to applications.

Use of this method will make the application nonportable, since the implementation of the DirectIO method is vendor-specific. An application that uses a DirectIO method on Vendor A's LineDisplay device cannot depend on using a Vendor B's device.


This event can be used to send vendor-specific information directly to the application. This event provides a means for a vendor-specific UnifiedPOS service to provide events to the application that are not otherwise supported by the UnifiedPOS control.

Using this event will make an application incompatible with devices from other vendors.

See Also

Other Resources

Developing Service Objects Using Base Classes