Control.AccessibilityNotifyClients 方法

定义

向具有辅助功能的客户端应用程序通知 AccessibleEventsNotifies the accessibility client applications of AccessibleEvents.

重载

AccessibilityNotifyClients(AccessibleEvents, Int32)

就指定子控件的指定 AccessibleEvents 通知辅助功能客户端应用程序。Notifies the accessibility client applications of the specified AccessibleEvents for the specified child control.

AccessibilityNotifyClients(AccessibleEvents, Int32, Int32)

就指定子控件的指定 AccessibleEvents 通知辅助功能客户端应用程序。Notifies the accessibility client applications of the specified AccessibleEvents for the specified child control .

AccessibilityNotifyClients(AccessibleEvents, Int32)

就指定子控件的指定 AccessibleEvents 通知辅助功能客户端应用程序。Notifies the accessibility client applications of the specified AccessibleEvents for the specified child control.

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

参数

accEvent
AccessibleEvents

要将其通报给具有辅助功能的客户端应用程序的 AccessibleEventsThe AccessibleEvents to notify the accessibility client applications of.

childID
Int32

就该辅助性事件要通知的子 ControlThe child Control to notify of the accessible event.

示例

下面的代码示例演示如何使用 AccessibleObjectControl.ControlAccessibleObject 类创建可访问感知的图表控件,以公开辅助性信息。The following code example demonstrates the creation of an accessibility-aware chart control, using the AccessibleObject and Control.ControlAccessibleObject classes to expose accessible information. 控件将两条曲线与图例一起绘制。The control plots two curves along with a legend. ControlAccessibleObject派生的 ChartControlAccessibleObject 类在 CreateAccessibilityInstance 方法中用于为图表控件提供自定义的可访问信息。The ChartControlAccessibleObject class, which derives from ControlAccessibleObject, is used in the CreateAccessibilityInstance method to provide custom accessible information for the chart control. 由于图表图例不是实际的基于 Control 的控件,而是由图表控件绘制,因此它不具有任何内置的可访问信息。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. 因此,ChartControlAccessibleObject 类将重写 GetChild 方法,以返回表示图例的每个部分可访问信息的 CurveLegendAccessibleObjectBecause of this, the ChartControlAccessibleObject class overrides the GetChild method to return the CurveLegendAccessibleObject that represents accessible information for each part of the legend. 当可访问感知的应用程序使用此控件时,控件可以提供必需的可访问信息。When an accessible-aware application uses this control, the control can provide the necessary accessible information.

此代码摘录演示了如何调用 AccessibilityNotifyClients 方法。This code excerpt demonstrates calling the AccessibilityNotifyClients method. 有关完整的代码示例,请参阅 AccessibleObject 类概述。See the AccessibleObject class overview for the complete code example.

   // 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

注解

必须为每个要通知的辅助功能客户端应用程序 AccessibleEvents 调用 Control.ControlAccessibleObject.NotifyClients 方法。You must call the Control.ControlAccessibleObject.NotifyClients method for each AccessibleEvents the accessibility client applications are to be notified of. 当设置属性或从事件处理程序中设置属性时,通常会调用 NotifyClients 方法。The NotifyClients method is typically called when a property is set or from within an event handler. 例如,你可以调用 NotifyClients 方法,并传入 Control.VisibleChanged 事件的事件处理程序中的 HideAccessibleEvents 值。For example, you might call the NotifyClients method and pass in an AccessibleEvents value of Hide from within the event handler for the Control.VisibleChanged event.

另请参阅

AccessibilityNotifyClients(AccessibleEvents, Int32, Int32)

就指定子控件的指定 AccessibleEvents 通知辅助功能客户端应用程序。Notifies the accessibility client applications of the specified AccessibleEvents for the specified child control .

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)

参数

accEvent
AccessibleEvents

要将其通报给具有辅助功能的客户端应用程序的 AccessibleEventsThe AccessibleEvents to notify the accessibility client applications of.

objectID
Int32

AccessibleObject 的标识符。The identifier of the AccessibleObject.

childID
Int32

就该辅助性事件要通知的子 ControlThe child Control to notify of the accessible event.

适用于