Control.CreateAccessibilityInstance Control.CreateAccessibilityInstance Control.CreateAccessibilityInstance Control.CreateAccessibilityInstance Method

定义

为该控件创建一个新的辅助功能对象。Creates a new accessibility object for the control.

protected:
 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

返回

示例

下面的代码示例演示如何创建一个具有辅助功能的图表控件,并使用AccessibleObjectControl.ControlAccessibleObject类,以公开访问的信息。The following code example demonstrates the creation of an accessibility-aware chart control, using the AccessibleObject and Control.ControlAccessibleObject classes to expose accessible information. 控件绘制图例以及两条曲线。The control plots two curves along with a legend. ChartControlAccessibleObject类,该类派生自ControlAccessibleObject,在使用CreateAccessibilityInstance方法以提供自定义访问图表控件的信息。The ChartControlAccessibleObject class, which derives from ControlAccessibleObject, is used in the CreateAccessibilityInstance method to provide custom accessible information for the chart control. 因为不是实际图表图例Control-基于控制,但改为绘制由图表控件,它不提供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CurveLegendAccessibleObject,它表示每个部分的图例可访问信息。Because of this, the ChartControlAccessibleObject class overrides the GetChild method to return the CurveLegendAccessibleObject that represents accessible information for each part of the legend. 当辅助功能的应用程序使用该控件时,该控件可以提供所需的可访问信息。When an accessible-aware application uses this control, the control can provide the necessary accessible information.

此代码片段演示如何重写CreateAccessibilityInstance方法。This code excerpt demonstrates overriding the CreateAccessibilityInstance method. 请参阅AccessibleObject完整的代码示例的类概述。See the AccessibleObject class overview for the complete code example.

protected:
   // 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 

注解

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.

备注

获取或设置AccessibilityObject属性,必须添加对的引用Accessibility随一起安装的程序集.NET Framework.NET FrameworkTo get or set the AccessibilityObject property, you must add a reference to the Accessibility assembly installed with the .NET Framework.NET Framework.

继承者说明

重写时CreateAccessibilityInstance()在派生类中,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.

适用于

另请参阅