Export (0) Print
Expand All

CacheRequest Class

Specifies properties and patterns that the UI Automation framework caches when an AutomationElement is obtained.


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

public ref class CacheRequest sealed

The CacheRequest type exposes the following members.

Public methodCacheRequestInitializes a new instance of the CacheRequest class.

Public propertyAutomationElementModeGets or sets a value that specifies whether returned elements should contain full references to the underlying user interface (UI), or only cached information.
Public propertyStatic memberCurrentGets the CacheRequest that is active on the current thread.
Public propertyTreeFilterGets or sets a value specifying the view of the UI Automation element tree to use when caching.
Public propertyTreeScopeGets or sets a value that specifies whether caching is done only for the root of the subtree, or also for its children or descendants.

Public methodActivateSets this CacheRequest as the active specification for the items that are returned when an AutomationElement is requested on the same thread.
Public methodAdd(AutomationPattern)Adds the specified AutomationPattern identifier to this CacheRequest.
Public methodAdd(AutomationProperty)Adds the specified AutomationProperty identifier to this CacheRequest.
Public methodCloneCreates a copy of this CacheRequest.
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodPopRemoves the active CacheRequest from the internal stack for the current thread.
Public methodPushPlaces the CacheRequest on the internal state stack, making it the active request on the current thread.
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)

Retrieving properties and patterns through UI Automation requires cross-process calls that can slow down performance. By caching values of proprieties and patterns in a batch operation, you can enhance the performance of your application.

Create a new cache request by calling the class constructor. The request is populated by repeated calls to the Add method.

Only a single CacheRequest can be active. There are two ways to activate a request:

  • Call Activate on the request. This pushes the request onto the stack, and the request is popped when the object is disposed. To ensure disposal even if an exception is raised, use the return value from Activate within a using block (Using in Microsoft Visual Basic .NET).

  • Put the request onto the internal stack by calling Push. Only the topmost request on the stack is active, and it must be the next one removed from the stack by Pop. Popping the request deactivates it.

UI Automation elements obtained while the request is active will have cached values for the properties and patterns specified.

The following example shows how to use Activate to cache patterns and properties.

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

The following example shows how to use Push and Pop to cache patterns and properties.

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

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
© 2014 Microsoft