Control.AccessibilityNotifyClients 方法

参考

定义

命名空间:: System.Windows.Forms

程序集:: System.Windows.Forms.dll

重要

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向具有辅助功能的客户端应用程序通知 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。
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。

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。

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)

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 AccessibleEvents。

childID: Int32

就该辅助性事件要通知的子 Control。

示例

下面的代码示例演示如何创建辅助功能感知图表控件，并使用 AccessibleObject 和 Control.ControlAccessibleObject 类公开可访问的信息。控件绘制两条曲线以及一个图例。 ChartControlAccessibleObject派生自 ControlAccessibleObject的类在方法中CreateAccessibilityInstance用于为图表控件提供自定义可访问信息。由于图表图例不是基于实际 Control 控件，而是由图表控件绘制的，因此它没有任何内置的可访问信息。因此， ChartControlAccessibleObject 类会重写 GetChild 方法，以返回 CurveLegendAccessibleObject 表示图例每个部分的可访问信息的。当可访问的应用程序使用此控件时，该控件可以提供必要的可访问信息。

此代码摘录演示了调用 AccessibilityNotifyClients 方法。有关完整的代码示例， AccessibleObject 请参阅类概述。

   // 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

必须针对要通知的每个AccessibleEvents辅助功能客户端应用程序调用 Control.ControlAccessibleObject.NotifyClients 方法。 NotifyClients通常当设置属性时或从事件处理程序中调用方法。例如，可以调用方法，NotifyClients并从事件的事件处理程序Control.VisibleChanged中AccessibleEvents传入值Hide。

另请参阅

适用于

AccessibilityNotifyClients(AccessibleEvents, Int32, Int32)