MSAA, UIA and WinForms in .Net

Another item for programmers, more on UIA and MSAA and developing accessible user interfaces, following on from using WPF/XAML with MSAA and UIA.

This is a super-quick guide to using WinForms to make UIs that work well with screenreaders like NVDA or Thunder or JAWS.

• You don’t need to do anything to Button, CheckBox, MenuItem or MenuStrip controls – other than put some text on them! Image-only controls are no good. It’s fine if only the image is shown to the end user and the text is hidden.
• You can correctly label content controls that don’t have a Text property, like TextBox, ListBox, ListView, ComboBox, ProgressBar and the like, in one of two ways:
  • Put a Label just before the control you want to label in the tab index order. The Text on the Label labels the control. Use the TabIndex property to make sure the order is correct.
  • Set the AccessibleName property on the content control itself. This labels the control for the screenreader.
• Groupbox controls don’t label their contents, use one of the other techniques here.
• You almost certainly want to avoid labelling Panel controls, since they are generally for layout, which is communicated to the screenreader user in other ways than labeling.
• For WebBrowser controls you need to think about the content in terms of web accessibility – use label elements, ARIA, and other HTML accessibility techniques. You might also need to label the actual WebBrowser control on your form with a Label or AccessibleName, just like any other content control.

Unsurprisingly, these techniques are basically the same as writing forms using the Windows C++ API, since WinForms is a wrapper round that.