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AccessibleObject.Parent Property

Gets the parent of an accessible object.

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

Public Overridable ReadOnly Property Parent As AccessibleObject

Property Value

Type: System.Windows.Forms.AccessibleObject
An AccessibleObject that represents the parent of an accessible object, or Nothing if there is no parent object.

Notes to Inheritors

All objects should support this property.

The following 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 have 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 Parent property. See the AccessibleObject class overview for the complete code example.

' Inner class CurveLegendAccessibleObject represents accessible information  
' associated with the CurveLegend object. 
Public Class CurveLegendAccessibleObject
    Inherits AccessibleObject

    Private curveLegend As CurveLegend

    Public Sub New(curveLegend As CurveLegend)
        Me.curveLegend = curveLegend
    End Sub 'New 

    ' Private property that helps get the reference to the parent ChartControl.                 
    Private ReadOnly Property ChartControl() As ChartControlAccessibleObject
            Return CType(Parent, ChartControlAccessibleObject)
        End Get 
    End Property 

    ' Friend helper function that returns the ID for this CurveLegend.                 
    Friend ReadOnly Property ID() As Integer 
            Dim i As Integer 
            For i = 0 To (ChartControl.GetChildCount()) - 1
                If ChartControl.GetChild(i) Is Me Then 
                    Return i
                End If 
            Next i
            Return - 1
        End Get 
    End Property 

    ' Gets the Bounds for the CurveLegend. This is used by accessibility programs. 
    Public Overrides ReadOnly Property Bounds() As Rectangle
            ' The bounds is in screen coordinates. 
            Dim loc As Point = curveLegend.Location
            Return New Rectangle(curveLegend.chart.PointToScreen(loc), curveLegend.Size)
        End Get 
    End Property 

    ' Gets or sets the Name for the CurveLegend. This is used by accessibility programs.                 
    Public Overrides Property Name() As String 
            Return curveLegend.Name
        End Get 
            curveLegend.Name = value
        End Set 
    End Property 

    ' Gets the Curve Legend Parent's Accessible object. 
    ' This is used by accessibility programs.                 
    Public Overrides ReadOnly Property Parent() As AccessibleObject
            Return curveLegend.chart.AccessibilityObject
        End Get 
    End Property 

    ' Gets the role for the CurveLegend. This is used by accessibility programs.                 
    Public Overrides ReadOnly Property Role() As AccessibleRole
            Return System.Windows.Forms.AccessibleRole.StaticText
        End Get 
    End Property 

    ' Gets the state based on the selection for the CurveLegend.  
    ' This is used by accessibility programs.                 
    Public Overrides ReadOnly Property State() As AccessibleStates
            Dim stateTemp As AccessibleStates = AccessibleStates.Selectable
            If curveLegend.Selected Then
                stateTemp = stateTemp Or AccessibleStates.Selected
            End If 
            Return stateTemp
        End Get 
    End Property 

    ' Navigates through siblings of this CurveLegend. This is used by accessibility programs.                 
    Public Overrides Function Navigate(navdir As AccessibleNavigation) As AccessibleObject
        ' Use the Friend NavigateFromChild helper function that exists 
        ' on ChartControlAccessibleObject. 
        Return ChartControl.NavigateFromChild(Me, navdir)
    End Function 

    ' Selects or unselects this CurveLegend. This is used by accessibility programs. 
    Public Overrides Sub [Select](selection As AccessibleSelection)

        ' Use the internal SelectChild helper function that exists 
        ' on ChartControlAccessibleObject.
        ChartControl.SelectChild(Me, selection)
    End Sub 

End Class 'CurveLegendAccessibleObject

.NET Framework

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

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
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