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Control.CreateAccessibilityInstance Method

Creates a new accessibility object for the control.

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

protected virtual AccessibleObject CreateAccessibilityInstance()

Return Value

Type: System.Windows.Forms.AccessibleObject
A new AccessibleObject for the control.

If you do not explicitly call the CreateAccessibilityInstance method, it will be called when the AccessibilityObject property is referenced.

NoteNote

To get or set the AccessibilityObject property, you must add a reference to the Accessibility assembly installed with the .NET Framework.

Notes to Inheritors

When overriding CreateAccessibilityInstance in a derived class, do not call the base class's CreateAccessibilityInstance method.

The following code example demonstrates the creation of an accessibility-aware chart control, using the AccessibleObject and Control.ControlAccessibleObject classes to expose accessible information. The control plots two curves along with a legend. The ChartControlAccessibleObject class, which derives from ControlAccessibleObject, is used in the CreateAccessibilityInstance method to provide custom accessible information for the chart control. Since the chart legend is not an actual Control -based control, but instead is drawn by the chart control, it does not any built-in accessible information. Because of this, the ChartControlAccessibleObject class overrides the GetChild method to return the CurveLegendAccessibleObject that represents accessible information for each part of the legend. When an accessible-aware application uses this control, the control can provide the necessary accessible information.

This code excerpt demonstrates overriding the CreateAccessibilityInstance method. See the AccessibleObject class overview for the complete code example.

// Overridden to return the custom AccessibleObject  
// for the entire chart. 
protected override AccessibleObject CreateAccessibilityInstance() 
{            
    return new ChartControlAccessibleObject(this);
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.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.

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