Control.CreateAccessibilityInstance Method


创建控件的新可访问性对象。Creates a new accessibility object for the control.

 virtual System::Windows::Forms::AccessibleObject ^ CreateAccessibilityInstance();
protected virtual System.Windows.Forms.AccessibleObject CreateAccessibilityInstance ();
abstract member CreateAccessibilityInstance : unit -> System.Windows.Forms.AccessibleObject
override this.CreateAccessibilityInstance : unit -> System.Windows.Forms.AccessibleObject
Protected Overridable Function CreateAccessibilityInstance () As AccessibleObject



控件的新 AccessibleObjectA new AccessibleObject for the control.


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 类会重写 GetChild 方法,以返回表示图例的每个部分的可访问信息的 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重写 CreateAccessibilityInstance 方法。This code excerpt demonstrates overriding the CreateAccessibilityInstance 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.

   // Overridden to return the custom AccessibleObject
   // for the entire chart.
   virtual AccessibleObject^ CreateAccessibilityInstance() override
      return gcnew ChartControlAccessibleObject( this );
// Overridden to return the custom AccessibleObject 
// for the entire chart.
protected override AccessibleObject CreateAccessibilityInstance() 
    return new ChartControlAccessibleObject(this);
' Overridden to return the custom AccessibleObject 
' for the entire chart.
Protected Overrides Function CreateAccessibilityInstance() As AccessibleObject
    Return New ChartControlAccessibleObject(Me)
End Function 


如果不显式调用 CreateAccessibilityInstance 方法,则在引用 AccessibilityObject 属性时将会调用此方法。If you do not explicitly call the CreateAccessibilityInstance method, it will be called when the AccessibilityObject property is referenced.


若要获取或设置 AccessibilityObject 属性,必须添加对安装了 .NET Framework.NET FrameworkAccessibility 程序集的引用。To get or set the AccessibilityObject property, you must add a reference to the Accessibility assembly installed with the .NET Framework.NET Framework.

Notes to Inheritors

当在派生类中重写 CreateAccessibilityInstance() 时,请勿调用基类的 CreateAccessibilityInstance() 方法。When overriding CreateAccessibilityInstance() in a derived class, do not call the base class's CreateAccessibilityInstance() method.

Applies to

See also