Control.AccessibilityNotifyClients Metodo

protected:
 void AccessibilityNotifyClients(System::Windows::Forms::AccessibleEvents accEvent, int childID);

protected public:
 void AccessibilityNotifyClients(System::Windows::Forms::AccessibleEvents accEvent, int childID);

protected void AccessibilityNotifyClients (System.Windows.Forms.AccessibleEvents accEvent, int childID);

protected internal void AccessibilityNotifyClients (System.Windows.Forms.AccessibleEvents accEvent, int childID);

member this.AccessibilityNotifyClients : System.Windows.Forms.AccessibleEvents * int -> unit

Protected Sub AccessibilityNotifyClients (accEvent As AccessibleEvents, childID As Integer)

Protected Friend Sub AccessibilityNotifyClients (accEvent As AccessibleEvents, childID As Integer)

Parametri

Esempio

Nell'esempio di codice seguente viene illustrata la creazione di un controllo grafico con riconoscimento dell'accessibilità usando le AccessibleObject classi e Control.ControlAccessibleObject per esporre informazioni accessibili. Il controllo traccia due curve insieme a una legenda. La ChartControlAccessibleObject classe, che deriva da ControlAccessibleObject, viene usata nel CreateAccessibilityInstance metodo per fornire informazioni accessibili personalizzate per il controllo grafico. Poiché la legenda del grafico non è un controllo effettivo Control basato su base, ma viene invece disegnato dal controllo grafico, non contiene informazioni accessibili predefinite. A causa di questo, la ChartControlAccessibleObject classe esegue l'override GetChild del metodo per restituire le CurveLegendAccessibleObject informazioni accessibili per ogni parte della legenda. Quando un'applicazione con riconoscimento accessibile usa questo controllo, il controllo può fornire le informazioni accessibili necessarie.

Questo estratto di codice illustra la chiamata al AccessibilityNotifyClients metodo. Vedere la panoramica della classe per l'esempio AccessibleObject di codice completo.

   // Gets or sets the location for the curve legend.
   Point get()
   {
      return location;
   }

   void set( Point value )
   {
      location = value;
      chart->Invalidate();
      
      // Notifies the chart of the location change. This is used for
      // the accessibility information. AccessibleEvents::LocationChange
      // tells the chart the reason for the notification.
      chart->AccessibilityNotifyClients( AccessibleEvents::LocationChange, (dynamic_cast<CurveLegendAccessibleObject^>(AccessibilityObject))->ID );
   }

}

property String^ Name 
{

   // Gets or sets the Name for the curve legend.
   String^ get()
   {
      return name;
   }

   void set( String^ value )
   {
      if ( name != value )
      {
         name = value;
         chart->Invalidate();
         
         // Notifies the chart of the name change. This is used for
         // the accessibility information. AccessibleEvents::NameChange
         // tells the chart the reason for the notification.
         chart->AccessibilityNotifyClients( AccessibleEvents::NameChange, (dynamic_cast<CurveLegendAccessibleObject^>(AccessibilityObject))->ID );
      }
   }

}

property bool Selected 
{

   // Gets or sets the Selected state for the curve legend.
   bool get()
   {
      return selected;
   }

   void set( bool value )
   {
      if ( selected != value )
      {
         selected = value;
         chart->Invalidate();
         
         // Notifies the chart of the selection value change. This is used for
         // the accessibility information. The AccessibleEvents value depends upon
         // if the selection is true (AccessibleEvents::SelectionAdd) or
         // false (AccessibleEvents::SelectionRemove).
         chart->AccessibilityNotifyClients( selected ? AccessibleEvents::SelectionAdd : AccessibleEvents::SelectionRemove, (dynamic_cast<CurveLegendAccessibleObject^>(AccessibilityObject))->ID );
      }
   }

    // Gets or sets the location for the curve legend.
    public Point Location
    {   
        get {
            return location;
        }
        set {
            location = value;
            chart.Invalidate();

            // Notifies the chart of the location change. This is used for
            // the accessibility information. AccessibleEvents.LocationChange
            // tells the chart the reason for the notification.

            chart.AccessibilityNotifyClients(AccessibleEvents.LocationChange, 
                ((CurveLegendAccessibleObject)AccessibilityObject).ID);
        }
    }            

    // Gets or sets the Name for the curve legend.
    public string Name
    {   
        get {
            return name;
        }
        set {
            if (name != value) 
            {
                name = value;
                chart.Invalidate();

                // Notifies the chart of the name change. This is used for
                // the accessibility information. AccessibleEvents.NameChange
                // tells the chart the reason for the notification.

                chart.AccessibilityNotifyClients(AccessibleEvents.NameChange, 
                    ((CurveLegendAccessibleObject)AccessibilityObject).ID);
            }
        }
    }

    // Gets or sets the Selected state for the curve legend.
    public bool Selected
    {   
        get {
            return selected;
        }
        set {
            if (selected != value) 
            {
                selected = value;
                chart.Invalidate();

                // Notifies the chart of the selection value change. This is used for
                // the accessibility information. The AccessibleEvents value depends upon
                // if the selection is true (AccessibleEvents.SelectionAdd) or 
                // false (AccessibleEvents.SelectionRemove).
                chart.AccessibilityNotifyClients(
                    selected ? AccessibleEvents.SelectionAdd : AccessibleEvents.SelectionRemove, 
                    ((CurveLegendAccessibleObject)AccessibilityObject).ID);
            }
        }
    }

' Gets or sets the location for the curve legend.            
Public Property Location() As Point
    Get
        Return m_location
    End Get
    Set
        m_location = value
        chart.Invalidate()

        ' Notifies the chart of the location change. This is used for
        ' the accessibility information. AccessibleEvents.LocationChange
        ' tells the chart the reason for the notification.
        chart.ExposeAccessibilityNotifyClients(AccessibleEvents.LocationChange, _
                CType(AccessibilityObject, CurveLegendAccessibleObject).ID)
    End Set
End Property

' Gets or sets the Name for the curve legend.            
Public Property Name() As String
    Get
        Return m_name
    End Get
    Set
        If m_name <> value Then
            m_name = value
            chart.Invalidate()

            ' Notifies the chart of the name change. This is used for
            ' the accessibility information. AccessibleEvents.NameChange
            ' tells the chart the reason for the notification. 
            chart.ExposeAccessibilityNotifyClients(AccessibleEvents.NameChange, _
                    CType(AccessibilityObject, CurveLegendAccessibleObject).ID)
        End If
    End Set
End Property

' Gets or sets the Selected state for the curve legend.            
Public Property Selected() As Boolean
    Get
        Return m_selected
    End Get
    Set
        If m_selected <> value Then
            m_selected = value
            chart.Invalidate()

            ' Notifies the chart of the selection value change. This is used for
            ' the accessibility information. The AccessibleEvents value varies
            ' on whether the selection is true (AccessibleEvents.SelectionAdd) or 
            ' false (AccessibleEvents.SelectionRemove). 
            If m_selected Then
                chart.ExposeAccessibilityNotifyClients(AccessibleEvents.SelectionAdd, _
                        CType(AccessibilityObject, CurveLegendAccessibleObject).ID) 
            Else
                chart.ExposeAccessibilityNotifyClients(AccessibleEvents.SelectionRemove, _
                        CType(AccessibilityObject, CurveLegendAccessibleObject).ID) 
            End If
        End If
    End Set
End Property

Commenti

È necessario chiamare il Control.ControlAccessibleObject.NotifyClients metodo per ogni AccessibleEvents applicazione client di accessibilità per ricevere una notifica. Il NotifyClients metodo viene in genere chiamato quando una proprietà è impostata o dall'interno di un gestore eventi. Ad esempio, è possibile chiamare il NotifyClients metodo e passare un AccessibleEvents valore di Hide dall'interno del gestore eventi per l'evento Control.VisibleChanged .

Vedi anche

• AccessibleEvents
• Controls

protected:
 void AccessibilityNotifyClients(System::Windows::Forms::AccessibleEvents accEvent, int objectID, int childID);

protected void AccessibilityNotifyClients (System.Windows.Forms.AccessibleEvents accEvent, int objectID, int childID);

member this.AccessibilityNotifyClients : System.Windows.Forms.AccessibleEvents * int * int -> unit

Protected Sub AccessibilityNotifyClients (accEvent As AccessibleEvents, objectID As Integer, childID As Integer)

Parametri