AccessibleObject.Bounds Propriété

public:
 virtual property System::Drawing::Rectangle Bounds { System::Drawing::Rectangle get(); };

public virtual System.Drawing.Rectangle Bounds { get; }

member this.Bounds : System.Drawing.Rectangle

Public Overridable ReadOnly Property Bounds As Rectangle

Valeur de propriété

Rectangle qui représente les limites de l'objet accessible.

Exceptions

Exemples

L’exemple suivant illustre la création d’un contrôle de graphique prenant en charge l’accessibilité, à l’aide des AccessibleObject classes et Control.ControlAccessibleObject pour exposer des informations accessibles. Le contrôle trace deux courbes avec une légende. La ChartControlAccessibleObject classe, qui dérive de ControlAccessibleObject, est utilisée dans la CreateAccessibilityInstance méthode pour fournir des informations accessibles personnalisées pour le contrôle de graphique. Étant donné que la légende de graphique n’est pas un Control contrôle basé sur un réel, mais qu’elle est dessinée par le contrôle de graphique, elle ne dispose pas d’informations accessibles intégrées. Pour cette raison, la ChartControlAccessibleObject classe remplace la GetChild méthode pour retourner le qui représente les CurveLegendAccessibleObject informations accessibles pour chaque partie de la légende. Lorsqu’une application compatible avec l’accessibilité utilise ce contrôle, le contrôle peut fournir les informations accessibles nécessaires.

Cet extrait de code illustre la substitution de la Bounds propriété. Consultez la vue d’ensemble AccessibleObject de la classe pour obtenir l’exemple de code complet.

   // 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

Remarques

La Bounds propriété récupère le rectangle englobant de l’objet dans les coordonnées d’écran. Si l’objet a une forme nonrectangulaire, cette propriété représente le plus petit rectangle qui englobe complètement l’ensemble de la région de l’objet. Par conséquent, pour les objets nonrectangulaires tels que les éléments d’affichage de liste, les coordonnées du rectangle englobant de l’objet peuvent échouer, si elles sont testées, en appelant la HitTest méthode, car HitTest détermine les limites de l’objet sur une base pixel par pixel.

Notes pour les héritiers

L’implémentation par défaut retourne le rectangle englobant de l’objet accessible si l’objet encapsule un contrôle système ; sinon, il retourne Empty. Tous les objets accessibles visibles doivent prendre en charge cette méthode. Les objets audio ne prennent pas en charge cette méthode.

S’applique à

Voir aussi

• DefaultAction
• Description
• Help
• KeyboardShortcut
• Name
• Parent
• Role
• State
• Value