Accessibility Application Development (Windows CE 5.0)

Article
09/14/2012

Microsoft® Windows® CE 5.0 provides a set of accessibility options that allow persons with disabilities to use computers more easily.

The following table shows the accessibility options that Windows CE provides and the structures that applications use with the SystemParametersInfo function to query or set the parameters for the option.

Option	Structure	Description
Accessibility time-out	ACCESSTIMEOUT	Enables a user to specify a time-out interval after which accessibility options turn off automatically. For more information see Setting Accessibility Time-out Periods.
High-contrast mode	HIGHCONTRAST	Provides high contrast between foreground and background visuals. For more information see Enabling High Contrast.
Mouse keys	MOUSEKEYS	Enables the user to control the mouse pointer by using the numeric keypad. For more information see Enabling Mouse Keys.
Show sounds	None	Indicates whether the user wants applications to present all important information in visual form, rather than presenting some important information only in audible form. For more information see Enabling Show Sounds.
Sound sentry	SOUNDSENTRY	Displays a visual signal when a sound is generated by a Windows CE–based application. For more information see Enabling Sound Sentry.
Sticky keys	STICKYKEYS	Enables the user to type key combinations, such as CTRL+ALT+DEL, in sequence rather than simultaneously. For more information see Enabling Sticky Keys.
Toggle keys	TOGGLEKEYS	Provides sound feedback when the user turns on or off the CAPS LOCK, NUM LOCK, or SCROLL LOCK key. For more information see Enabling Toggle Keys.

The SystemParametersInfo function provides the programming interface to the accessibility options. You can use this function in Control Panel applications or other programs that allow the user to customize the environment. The SystemParametersInfo function allows you to perform the following tasks:

Query the system to determine the availability and current state of a specified accessibility option.
Enable an accessibility option and specify parameters that control the behavior of the option.
Disable an accessibility option.
Enable a hot key that allows the user to enable or disable an accessibility option.