InvokePattern

InvokePattern is a UI Automation pattern that represents a control that can be invoked, such as a button or menu item. UI Automation clients use this pattern to activate or perform the default action of a control. For example, a client might use InvokePattern to simulate a user clicking a button.

The InvokePattern has a single method, Invoke. Calling this method performs the control's default action. Controls that implement InvokePattern are typically interactive and respond to user input by performing a specific task. Examples include buttons, checkboxes, radio buttons, menu items, and hyperlinks.

UI Automation providers implement InvokePattern to expose the invokable nature of their controls. This allows assistive technologies and other UI Automation clients to interact with these controls programmatically. For instance, a screen reader might use InvokePattern to activate a selected button when a user presses a specific key combination.

When Invoke is called, the control should perform its primary action. If the action is already in progress or cannot be performed, the provider should not throw an exception but rather indicate the failure through other means if necessary, such as returning a result code or setting an appropriate property. The InvokePattern is fundamental for enabling programmatic interaction with a wide range of common UI elements.