ExpandCollapsePattern::Collapse Method ()

 

Hides all descendant nodes, controls, or content of the AutomationElement.

Namespace:   System.Windows.Automation
Assembly:  UIAutomationClient (in UIAutomationClient.dll)

public:
void Collapse()

Exception Condition
InvalidOperationException

Collapse is called when the ExpandCollapseState = LeafNode.

This is a blocking method that returns after the UI Automation element has been collapsed.

There are cases when a UI Automation element that is marked as a leaf node might not know whether it has children until either the Collapse or the Expand method is called. This behavior is possible with a tree view control that does delayed loading of its child items. For example, Microsoft Windows Explorer might display the expand icon for a node even though there are currently no child items; when the icon is clicked, the control polls for child items, finds none, and removes the expand icon. In these cases clients should listen for a property-changed event on the ExpandCollapseState property by registering an event handler with the AddAutomationPropertyChangedEventHandler method.

In the following example, a UI Automation element representing a menu item is passed to a function that attempts to expand or collapse the menu item based on its current ExpandCollapseState.

No code example is currently available or this language may not be supported.
No code example is currently available or this language may not be supported.

.NET Framework
Available since 3.0

ExpandCollapsePattern Class
System.Windows.Automation Namespace
InvokePattern and ExpandCollapsePattern Menu Item Sample

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