UI Automation Properties Overview
This documentation is intended for .NET Framework developers who want to use the managed UI Automation classes defined in the System.Windows.Automation namespace. For the latest information about UI Automation, see Windows Automation API: UI Automation.
UI Automation providers expose properties on Microsoft UI Automation elements. These properties enable UI Automation client applications to discover information about pieces of the user interface (UI), especially controls, including both static and dynamic data.
This section gives a broad overview of Microsoft UI Automation properties. More specific information is given in the following topics:
Every property is identified by a number and a name. The names of properties are used only for debugging and diagnosis. Providers use the numeric IDs to identify incoming property requests. Client applications, however, only use AutomationProperty, which encapsulates the number and name, to identify properties they wish to retrieve.
AutomationProperty objects representing particular properties are available as fields in various classes. For security reasons, UI Automation providers obtain these objects from a separate set of classes that are contained in Uiautomationtypes.dll.
The following table categorizes properties by the classes that contain the AutomationProperty IDs.
Kinds of properties
Clients get IDs from
Providers get IDs from
Properties common to all elements (see following tables)
Position of a docking window
State of an element that can expand and collapse
Properties of an item in a grid
Properties of a grid
Current and supported view of an element that has multiple views
Properties of an element that moves over a range of values, such as a slider
Properties of a scrolling window
Status and container of an item that can be selected, as in a list
Properties of a control that contains selection items
Column and row headers of an item in a table
Column and row headers, and orientation, of a table
State of a toggle control
Capabilities of an element that can be moved, rotated, or resized
Value and read/write capabilities of an element that has a value
Capabilities and state of a window
The following tables categorize the properties whose IDs are found in AutomationElement and AutomationElementIdentifiers. These properties are common to all controls. All but a few of them are likely to be static over the lifetime of the provider application; most dynamic properties are associated with control patterns.
The Property Access column lists any other accessors for each property, in addition to GetCurrentPropertyValue and GetCachedPropertyValue. For more information on getting properties in a client application, see UI Automation Properties for Clients.
For specific information about each property, follow the link in the Property Access column.
Support for Patterns
Closely tied in with the properties in UI Automation is the concept of property-changed events. For dynamic properties, the client application needs a way to know that a property value has changed, so that it can update its cache of information or react to the new information in some other way.
Providers raise events when something in the UI changes. For example, if a check box is selected or cleared, a property-changed event is raised by the provider's implementation of the Toggle pattern. Providers can raise events selectively, depending on whether any clients are listening for events, or listening for specific events.
Not all property changes raise events; that is entirely up to the implementation of the UI Automation provider for the element. For example, the standard proxy providers for list boxes do not raise an event when the SelectionProperty changes. In this case, the application instead must listen for an ElementSelectedEvent.
Clients listen for events by subscribing to them. Subscribing to events means creating delegate methods that can handle the events, and then passing the methods to UI Automation along with the specific events that will be dealt with in those methods. For property-changed events in particular, clients must implement AutomationPropertyChangedEventHandler.