AccessibleObject.Navigate(AccessibleNavigation) AccessibleObject.Navigate(AccessibleNavigation) AccessibleObject.Navigate(AccessibleNavigation) AccessibleObject.Navigate(AccessibleNavigation) Method

Définition

Navigue vers un autre objet accessible.Navigates to another accessible object.

public:
 virtual System::Windows::Forms::AccessibleObject ^ Navigate(System::Windows::Forms::AccessibleNavigation navdir);
public virtual System.Windows.Forms.AccessibleObject Navigate (System.Windows.Forms.AccessibleNavigation navdir);
abstract member Navigate : System.Windows.Forms.AccessibleNavigation -> System.Windows.Forms.AccessibleObject
override this.Navigate : System.Windows.Forms.AccessibleNavigation -> System.Windows.Forms.AccessibleObject
Public Overridable Function Navigate (navdir As AccessibleNavigation) As AccessibleObject

Paramètres

Retours

Exceptions

La tentative de navigation a échoué.The navigation attempt fails.

Exemples

L’exemple suivant illustre la création d’un contrôle de graphique prenant en charge l’accessibilité, à l’aide des classes AccessibleObject et Control.ControlAccessibleObject pour exposer des informations accessibles.The following example demonstrates the creation of an accessibility-aware chart control, using the AccessibleObject and Control.ControlAccessibleObject classes to expose accessible information. Le contrôle trace deux courbes avec une légende.The control plots two curves along with a legend. La classe ChartControlAccessibleObject, qui dérive de ControlAccessibleObject, est utilisée dans la méthode CreateAccessibilityInstance pour fournir des informations accessibles personnalisées pour le contrôle Chart.The ChartControlAccessibleObject class, which derives from ControlAccessibleObject, is used in the CreateAccessibilityInstance method to provide custom accessible information for the chart control. Étant donné que la légende du graphique n’est pas un contrôle réel basé sur Control, mais qu’elle est dessinée par le contrôle Chart, elle n’a pas d’informations accessibles intégrées.Since the chart legend is not an actual Control -based control, but instead is drawn by the chart control, it does not have any built-in accessible information. Pour cette raison, la classe ChartControlAccessibleObject remplace la méthode GetChild pour retourner le CurveLegendAccessibleObject qui représente des informations accessibles pour chaque partie de la légende.Because of this, the ChartControlAccessibleObject class overrides the GetChild method to return the CurveLegendAccessibleObject that represents accessible information for each part of the legend. Lorsqu’une application qui prend en charge l’accès utilise ce contrôle, le contrôle peut fournir les informations accessibles nécessaires.When an accessible-aware application uses this control, the control can provide the necessary accessible information.

Ce code montre comment substituer la méthode Navigate.This code demonstrates shows overriding the Navigate method. Consultez la vue d’ensemble de la classe AccessibleObject pour obtenir un exemple de code complet.See the AccessibleObject class overview for the complete code example.

   // 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 navigation, spatiale et logique, est toujours limitée aux éléments de l’interface utilisateur au sein d’un conteneur.Navigation, both spatial and logical, is always restricted to the user interface elements within a container. Avec la navigation spatiale, les clients peuvent naviguer uniquement vers un frère de l’objet de départ.With spatial navigation, clients can navigate only to a sibling of the starting object. En fonction de l’indicateur de navigation utilisé avec la navigation logique, les clients peuvent accéder à un enfant ou à un frère de l’objet de départ.Depending on the navigational flag used with logical navigation, clients can navigate to either a child or to a sibling of the starting object. Cette méthode ne modifie pas la sélection ou le focus.This method does not change the selection or focus. Pour modifier le focus ou pour sélectionner un objet, utilisez Select.To change the focus or to select an object, use Select. La méthode Navigate récupère uniquement les éléments d’interface utilisateur qui ont un emplacement défini à l’écran.The Navigate method retrieves only user interface elements that have a defined screen location.

Notes pour les héritiers

Tous les objets visuels doivent prendre en charge cette méthode.All visual objects must support this method. Si un objet a l’État Invisible, la navigation vers cet objet masqué peut échouer.If an object has the state Invisible, navigation to this hidden object might fail. Certains éléments d’interface définis par le système, tels que les menus, les éléments de menu et les menus contextuels, permettent de naviguer vers des objets qui ne sont pas visibles.Some system-defined interface elements such as menus, menu items, and pop-up menus allow navigation to objects that are not visible. Toutefois, les autres éléments d’interface utilisateur définis par le système ne prennent pas en charge cette opération.However, other system-defined user interface elements do not support this. Si possible, les serveurs doivent prendre en charge la navigation vers des objets qui ne sont pas visibles, mais cette prise en charge n’est pas obligatoire et les clients ne doivent pas l’attendre.If possible, servers should support navigation to objects that are not visible, but this support is not required and clients should not expect it.

S’applique à