AccessibleObject.Select(AccessibleSelection) 方法

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

修改選取或者移動可存取物件的鍵盤焦點。

public:
 virtual void Select(System::Windows::Forms::AccessibleSelection flags);

public virtual void Select (System.Windows.Forms.AccessibleSelection flags);

abstract member Select : System.Windows.Forms.AccessibleSelection -> unit
override this.Select : System.Windows.Forms.AccessibleSelection -> unit

Public Overridable Sub Select (flags As AccessibleSelection)

參數

flags

AccessibleSelection

其中一個 AccessibleSelection 值。

例外狀況

COMException

無法執行選取。

範例

下列範例示範如何使用 AccessibleObject 和 Control.ControlAccessibleObject 類別來公開無障礙資訊，建立協助工具感知圖表控制項。 控制項會繪製兩條曲線以及圖例。 衍生 ChartControlAccessibleObject 自 ControlAccessibleObject 的 類別用於 方法中 CreateAccessibilityInstance ，以提供圖表控制項的自訂可存取訊號。 由於圖表圖例不是實際的 Control 控制項，而是由圖表控制項繪製，因此它沒有任何內建的可存取訊號。 因此，類別會 ChartControlAccessibleObjectGetChild 覆寫 方法，以傳回 CurveLegendAccessibleObject ，代表圖例每個部分的可存取訊號。 當可存取感知應用程式使用此控制項時，控制項可以提供必要的可存取訊號。

此程式碼示範如何覆寫 Select 方法。 如需完整的程式碼範例， AccessibleObject 請參閱 類別概觀。

   // Inner class CurveLegendAccessibleObject represents accessible information
   // associated with the CurveLegend object.
public:
   ref class CurveLegendAccessibleObject: public AccessibleObject
   {
   private:
      CurveLegend^ curveLegend;

   public:
      CurveLegendAccessibleObject( CurveLegend^ curveLegend )
         : AccessibleObject()
      {
         this->curveLegend = curveLegend;
      }


   private:

      property ChartControlAccessibleObject^ ChartControl 
      {

         // Private property that helps get the reference to the parent ChartControl.
         ChartControlAccessibleObject^ get()
         {
            return dynamic_cast<ChartControlAccessibleObject^>(Parent);
         }

      }

   internal:

      property int ID 
      {

         // Internal helper function that returns the ID for this CurveLegend.
         int get()
         {
            for ( int i = 0; i < ChartControl->GetChildCount(); i++ )
            {
               if ( ChartControl->GetChild( i ) == this )
               {
                  return i;
               }

            }
            return  -1;
         }

      }

   public:

      property Rectangle Bounds 
      {

         // Gets the Bounds for the CurveLegend. This is used by accessibility programs.
         virtual Rectangle get() override
         {
            
            // The bounds is in screen coordinates.
            Point loc = curveLegend->Location;
            return Rectangle(curveLegend->chart->PointToScreen( loc ),curveLegend->Size);
         }

      }

      property String^ Name 
      {

         // Gets or sets the Name for the CurveLegend. This is used by accessibility programs.
         virtual String^ get() override
         {
            return curveLegend->Name;
         }

         virtual void set( String^ value ) override
         {
            curveLegend->Name = value;
         }

      }

      property AccessibleObject^ Parent 
      {

         // Gets the Curve Legend Parent's Accessible object.
         // This is used by accessibility programs.
         virtual AccessibleObject^ get() override
         {
            return curveLegend->chart->AccessibilityObject;
         }

      }

      property System::Windows::Forms::AccessibleRole Role 
      {

         // Gets the role for the CurveLegend. This is used by accessibility programs.
         virtual System::Windows::Forms::AccessibleRole get() override
         {
            return ::AccessibleRole::StaticText;
         }

      }

      property AccessibleStates State 
      {

         // Gets the state based on the selection for the CurveLegend.
         // This is used by accessibility programs.
         virtual AccessibleStates get() override
         {
            AccessibleStates state = AccessibleStates::Selectable;
            if ( curveLegend->Selected )
            {
               state = static_cast<AccessibleStates>(state | AccessibleStates::Selected);
            }

            return state;
         }

      }

      // Navigates through siblings of this CurveLegend. This is used by accessibility programs.
      virtual AccessibleObject^ Navigate( AccessibleNavigation navdir ) override
      {
         
         // Uses the internal NavigateFromChild helper function that exists
         // on ChartControlAccessibleObject.
         return ChartControl->NavigateFromChild( this, navdir );
      }


      // Selects or unselects this CurveLegend. This is used by accessibility programs.
      virtual void Select( AccessibleSelection selection ) override
      {
         
         // Uses the internal SelectChild helper function that exists
         // on ChartControlAccessibleObject.
         ChartControl->SelectChild( this, selection );
      }

   };

// Inner class CurveLegendAccessibleObject represents accessible information 
// associated with the CurveLegend object.
public class CurveLegendAccessibleObject : AccessibleObject
{
    private CurveLegend curveLegend;

    public CurveLegendAccessibleObject(CurveLegend curveLegend) : base() 
    {
        this.curveLegend = curveLegend;                    
    }                

    // Private property that helps get the reference to the parent ChartControl.
    private ChartControlAccessibleObject ChartControl
    {   
        get {
            return Parent as ChartControlAccessibleObject;
        }
    }

    // Internal helper function that returns the ID for this CurveLegend.
    internal int ID
    {
        get {
            for(int i = 0; i < ChartControl.GetChildCount(); i++) {
                if (ChartControl.GetChild(i) == this) {
                    return i;
                }
            }
            return -1;
        }
    }

    // Gets the Bounds for the CurveLegend. This is used by accessibility programs.
    public override Rectangle Bounds
    {
        get {                        
            // The bounds is in screen coordinates.
            Point loc = curveLegend.Location;
            return new Rectangle(curveLegend.chart.PointToScreen(loc), curveLegend.Size);
        }
    }

    // Gets or sets the Name for the CurveLegend. This is used by accessibility programs.
    public override string Name
    {
        get {
            return curveLegend.Name;
        }
        set {
            curveLegend.Name = value;                        
        }
    }

    // Gets the Curve Legend Parent's Accessible object.
    // This is used by accessibility programs.
    public override AccessibleObject Parent
    {
        get {
            return curveLegend.chart.AccessibilityObject;
        }
    }

    // Gets the role for the CurveLegend. This is used by accessibility programs.
    public override AccessibleRole Role 
    {
        get {
            return AccessibleRole.StaticText;
        }
    }

    // Gets the state based on the selection for the CurveLegend. 
    // This is used by accessibility programs.
    public override AccessibleStates State 
    {
        get {
            AccessibleStates state = AccessibleStates.Selectable;
            if (curveLegend.Selected) 
            {
                state |= AccessibleStates.Selected;
            }
            return state;
        }
    }

    // Navigates through siblings of this CurveLegend. This is used by accessibility programs.
    public override AccessibleObject Navigate(AccessibleNavigation navdir) 
    {
        // Uses the internal NavigateFromChild helper function that exists
        // on ChartControlAccessibleObject.
        return ChartControl.NavigateFromChild(this, navdir);
    }

    // Selects or unselects this CurveLegend. This is used by accessibility programs.
    public override void Select(AccessibleSelection selection) 
    {
        // Uses the internal SelectChild helper function that exists
        // on ChartControlAccessibleObject.
        ChartControl.SelectChild(this, selection);
    }
}

' Inner class CurveLegendAccessibleObject represents accessible information 
' associated with the CurveLegend object.
Public Class CurveLegendAccessibleObject
    Inherits AccessibleObject

    Private curveLegend As CurveLegend
    
    Public Sub New(curveLegend As CurveLegend)
        Me.curveLegend = curveLegend
    End Sub
    
    ' Private property that helps get the reference to the parent ChartControl.                
    Private ReadOnly Property ChartControl() As ChartControlAccessibleObject
        Get
            Return CType(Parent, ChartControlAccessibleObject)
        End Get
    End Property

    ' Friend helper function that returns the ID for this CurveLegend.                
    Friend ReadOnly Property ID() As Integer
        Get
            Dim i As Integer
            For i = 0 To (ChartControl.GetChildCount()) - 1
                If ChartControl.GetChild(i) Is Me Then
                    Return i
                End If
            Next i
            Return - 1
        End Get
    End Property
    
    ' Gets the Bounds for the CurveLegend. This is used by accessibility programs.
    Public Overrides ReadOnly Property Bounds() As Rectangle
        Get
            ' The bounds is in screen coordinates.
            Dim loc As Point = curveLegend.Location
            Return New Rectangle(curveLegend.chart.PointToScreen(loc), curveLegend.Size)
        End Get
    End Property

    ' Gets or sets the Name for the CurveLegend. This is used by accessibility programs.                
    Public Overrides Property Name() As String
        Get
            Return curveLegend.Name
        End Get
        Set
            curveLegend.Name = value
        End Set
    End Property
    
    ' Gets the Curve Legend Parent's Accessible object.
    ' This is used by accessibility programs.                
    Public Overrides ReadOnly Property Parent() As AccessibleObject
        Get
            Return curveLegend.chart.AccessibilityObject
        End Get
    End Property
    
    ' Gets the role for the CurveLegend. This is used by accessibility programs.                
    Public Overrides ReadOnly Property Role() As AccessibleRole
        Get
            Return System.Windows.Forms.AccessibleRole.StaticText
        End Get
    End Property

    ' Gets the state based on the selection for the CurveLegend. 
    ' This is used by accessibility programs.                
    Public Overrides ReadOnly Property State() As AccessibleStates
        Get
            Dim stateTemp As AccessibleStates = AccessibleStates.Selectable
            If curveLegend.Selected Then
                stateTemp = stateTemp Or AccessibleStates.Selected
            End If
            Return stateTemp
        End Get
    End Property
    
    ' Navigates through siblings of this CurveLegend. This is used by accessibility programs.                
    Public Overrides Function Navigate(navdir As AccessibleNavigation) As AccessibleObject
        ' Use the Friend NavigateFromChild helper function that exists
        ' on ChartControlAccessibleObject.
        Return ChartControl.NavigateFromChild(Me, navdir)
    End Function
    
    ' Selects or unselects this CurveLegend. This is used by accessibility programs.
    Public Overrides Sub [Select](selection As AccessibleSelection)

        ' Use the internal SelectChild helper function that exists
        ' on ChartControlAccessibleObject.
        ChartControl.SelectChild(Me, selection)
    End Sub

End Class

備註

應用程式可以使用這個方法來執行複雜的選取作業。

下列描述 AccessibleSelection 呼叫 Select 以執行複雜選取作業時所要指定的值。

作業	旗標組合
模擬點選	AccessibleSelection.TakeFocusORAccessibleSelection.TakeSelection注意： 如果從您自己的應用程式內呼叫，這個組合將不會選取所需的控制項。 不過，如果從外部應用程式呼叫，則會有所需的效果。
若要藉由模擬 CTRL + 按一下來選取目標專案	AccessibleSelection.TakeFocus OR AccessibleSelection.AddSelection
若要藉由模擬 CTRL + 按一下來取消選取目標專案	AccessibleSelection.TakeFocus OR AccessibleSelection.RemoveSelection
模擬 SHIFT + 按一下	AccessibleSelection.TakeFocus OR AccessibleSelection.ExtendSelection
選取物件範圍，並將焦點放在最後一個物件上	在起始物件上指定 AccessibleSelection.TakeFocus ，以設定選取錨點。 然後再次呼叫 Select ，並在最後一個物件上指定 ORAccessibleSelection.TakeFocusAccessibleSelection.ExtendSelection 。
取消選取所有物件	在任何 物件上指定 AccessibleSelection.TakeSelection 。 這個旗標會取消選取所有選取的物件，但剛選取的物件除外。 然後再次呼叫 Select ，並在相同的物件上指定 AccessibleSelection.RemoveSelection 。

給繼承者的注意事項

所有可以選取或接收鍵盤焦點的物件都必須支援這個方法。