AccessibleRole Enum

Reference

Definition

Namespace:: System.Windows.Forms

Assembly:: System.Windows.Forms.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Specifies values representing possible roles for an accessible object.

public enum class AccessibleRole

public enum AccessibleRole

type AccessibleRole =

Public Enum AccessibleRole

Inheritance: Object

ValueType

Enum
AccessibleRole

Fields

Name	Value	Description
Default	-1	A system-provided role.
None	0	No role.
TitleBar	1	A title or caption bar for a window.
MenuBar	2	A menu bar, usually beneath the title bar of a window, from which users can select menus.
ScrollBar	3	A vertical or horizontal scroll bar, which can be either part of the client area or used in a control.
Grip	4	A special mouse pointer, which allows a user to manipulate user interface elements such as a window. For example, a user can click and drag a sizing grip in the lower-right corner of a window to resize it.
Sound	5	A system sound, which is associated with various system events.
Cursor	6	A mouse pointer.
Caret	7	A caret, which is a flashing line, block, or bitmap that marks the location of the insertion point in a window's client area.
Alert	8	An alert or condition that you can notify a user about. Use this role only for objects that embody an alert but are not associated with another user interface element, such as a message box, graphic, text, or sound.
Window	9	A window frame, which usually contains child objects such as a title bar, client, and other objects typically contained in a window.
Client	10	A window's user area.
MenuPopup	11	A menu, which presents a list of options from which the user can make a selection to perform an action. All menu types must have this role, including drop-down menus that are displayed by selection from a menu bar, and shortcut menus that are displayed when the right mouse button is clicked.
MenuItem	12	A menu item, which is an entry in a menu that a user can choose to carry out a command, select an option, or display another menu. Functionally, a menu item can be equivalent to a push button, radio button, check box, or menu.
ToolTip	13	A tool tip, which is a small rectangular pop-up window that displays a brief description of the purpose of a button.
Application	14	The main window for an application.
Document	15	A document window, which is always contained within an application window. This role applies only to multiple-document interface (MDI) windows and refers to an object that contains the MDI title bar.
Pane	16	A separate area in a frame, a split document window, or a rectangular area of the status bar that can be used to display information. Users can navigate between panes and within the contents of the current pane, but cannot navigate between items in different panes. Thus, panes represent a level of grouping lower than frame windows or documents, but above individual controls. Typically, the user navigates between panes by pressing TAB, F6, or CTRL+TAB, depending on the context.
Chart	17	A graphical image used to represent data.
Dialog	18	A dialog box or message box.
Border	19	A window border. The entire border is represented by a single object, rather than by separate objects for each side.
Grouping	20	The objects grouped in a logical manner. There can be a parent-child relationship between the grouping object and the objects it contains.
Separator	21	A space divided visually into two regions, such as a separator menu item or a separator dividing split panes within a window.
ToolBar	22	A toolbar, which is a grouping of controls that provide easy access to frequently used features.
StatusBar	23	A status bar, which is an area typically at the bottom of an application window that displays information about the current operation, state of the application, or selected object. The status bar can have multiple fields that display different kinds of information, such as an explanation of the currently selected menu command in the status bar.
Table	24	A table containing rows and columns of cells and, optionally, row headers and column headers.
ColumnHeader	25	A column header, which provides a visual label for a column in a table.
RowHeader	26	A row header, which provides a visual label for a table row.
Column	27	A column of cells within a table.
Row	28	A row of cells within a table.
Cell	29	A cell within a table.
Link	30	A link, which is a connection between a source document and a destination document. This object might look like text or a graphic, but it acts like a button.
HelpBalloon	31	A Help display in the form of a ToolTip or Help balloon, which contains buttons and labels that users can click to open custom Help topics.
Character	32	A cartoon-like graphic object, such as Microsoft Office Assistant, which is typically displayed to provide help to users of an application.
List	33	A list box, which allows the user to select one or more items.
ListItem	34	An item in a list box or the list portion of a combo box, drop-down list box, or drop-down combo box.
Outline	35	An outline or tree structure, such as a tree view control, which displays a hierarchical list and usually allows the user to expand and collapse branches.
OutlineItem	36	An item in an outline or tree structure.
PageTab	37	A property page that allows a user to view the attributes for a page, such as the page's title, whether it is a home page, or whether the page has been modified. Normally, the only child of this control is a grouped object that contains the contents of the associated page.
PropertyPage	38	A property page, which is a dialog box that controls the appearance and the behavior of an object, such as a file or resource. A property page's appearance differs according to its purpose.
Indicator	39	An indicator, such as a pointer graphic, that points to the current item.
Graphic	40	A picture.
StaticText	41	The read-only text, such as in a label, for other controls or instructions in a dialog box. Static text cannot be modified or selected.
Text	42	The selectable text that can be editable or read-only.
PushButton	43	A push button control, which is a small rectangular control that a user can turn on or off. A push button, also known as a command button, has a raised appearance in its default off state and a sunken appearance when it is turned on.
CheckButton	44	A check box control, which is an option that can be turned on or off independent of other options.
RadioButton	45	An option button, also known as a radio button. All objects sharing a single parent that have this attribute are assumed to be part of a single mutually exclusive group. You can use grouped objects to divide option buttons into separate groups when necessary.
ComboBox	46	A combo box, which is an edit control with an associated list box that provides a set of predefined choices.
DropList	47	A drop-down list box. This control shows one item and allows the user to display and select another from a list of alternative choices.
ProgressBar	48	A progress bar, which indicates the progress of a lengthy operation by displaying colored lines inside a horizontal rectangle. The length of the lines in relation to the length of the rectangle corresponds to the percentage of the operation that is complete. This control does not take user input.
Dial	49	A dial or knob. This can also be a read-only object, like a speedometer.
HotkeyField	50	A hot-key field that allows the user to enter a combination or sequence of keystrokes to be used as a hot key, which enables users to perform an action quickly. A hot-key control displays the keystrokes entered by the user and ensures that the user selects a valid key combination.
Slider	51	A control, sometimes called a trackbar, that enables a user to adjust a setting in given increments between minimum and maximum values by moving a slider. The volume controls in the Windows operating system are slider controls.
SpinButton	52	A spin box, also known as an up-down control, which contains a pair of arrow buttons. A user clicks the arrow buttons with a mouse to increment or decrement a value. A spin button control is most often used with a companion control, called a buddy window, where the current value is displayed.
Diagram	53	A graphical image used to diagram data.
Animation	54	An animation control, which contains content that is changing over time, such as a control that displays a series of bitmap frames, like a filmstrip. Animation controls are usually displayed when files are being copied, or when some other time-consuming task is being performed.
Equation	55	A mathematical equation.
ButtonDropDown	56	A button that drops down a list of items.
ButtonMenu	57	A button that drops down a menu.
ButtonDropDownGrid	58	A button that drops down a grid.
WhiteSpace	59	A blank space between other objects.
PageTabList	60	A container of page tab controls.
Clock	61	A control that displays the time.
SplitButton	62	A toolbar button that has a drop-down list icon directly adjacent to the button.
IpAddress	63	A control designed for entering Internet Protocol (IP) addresses.
OutlineButton	64	A control that navigates like an outline item.

Examples

The following code example demonstrates the creation of an accessibility-aware chart control, using the AccessibleObject and Control.ControlAccessibleObject classes to expose accessible information. The control plots two curves along with a legend. The ChartControlAccessibleObject class, which derives from ControlAccessibleObject, is used in the CreateAccessibilityInstance method to provide custom accessible information for the chart control. Because 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. Because of this, the ChartControlAccessibleObject class overrides the GetChild method to return the CurveLegendAccessibleObject that represents accessible information for each part of the legend. When an accessible-aware application uses this control, the control can provide the necessary accessible information.

This example demonstrates using the AccessibleRole enumeration with the Role property. See the AccessibleObject class overview for the complete code example.

// Inner class ChartControlAccessibleObject represents accessible information associated with the ChartControl.
// The ChartControlAccessibleObject is returned in the ChartControl::CreateAccessibilityInstance .
ref class ChartControlAccessibleObject: public ControlAccessibleObject
{
private:
   ChartControl^ chartControl;

public:
   ChartControlAccessibleObject( ChartControl^ ctrl )
      : ControlAccessibleObject( ctrl )
   {
      chartControl = ctrl;
   }


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

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

   }

   property AccessibleStates State 
   {

      // Gets the state for the Chart. This is used by accessibility programs.
      virtual AccessibleStates get() override
      {
         return AccessibleStates::ReadOnly;
      }

   }

   // The CurveLegend objects are "child" controls in terms of accessibility so
   // return the number of ChartLengend objects.
   virtual int GetChildCount() override
   {
      return chartControl->Legends->Length;
   }


   // Gets the Accessibility object of the child CurveLegend idetified by index.
   virtual AccessibleObject^ GetChild( int index ) override
   {
      if ( index >= 0 && index < chartControl->Legends->Length )
      {
         return chartControl->Legends[ index ]->AccessibilityObject;
      }

      return nullptr;
   }


internal:

   // Helper function that is used by the CurveLegend's accessibility object
   // to navigate between sibiling controls. Specifically, this function is used in
   // the CurveLegend::CurveLegendAccessibleObject.Navigate function.
   AccessibleObject^ NavigateFromChild( CurveLegend::CurveLegendAccessibleObject^ child, AccessibleNavigation navdir )
   {
      switch ( navdir )
      {
         case AccessibleNavigation::Down:
         case AccessibleNavigation::Next:
            return GetChild( child->ID + 1 );

         case AccessibleNavigation::Up:
         case AccessibleNavigation::Previous:
            return GetChild( child->ID - 1 );
      }
      return nullptr;
   }


   // Helper function that is used by the CurveLegend's accessibility object
   // to select a specific CurveLegend control. Specifically, this function is used
   // in the CurveLegend::CurveLegendAccessibleObject.Select function.
   void SelectChild( CurveLegend::CurveLegendAccessibleObject^ child, AccessibleSelection selection )
   {
      int childID = child->ID;
      
      // Determine which selection action should occur, based on the
      // AccessibleSelection value.
      if ( (selection & AccessibleSelection::TakeSelection) != (AccessibleSelection)0 )
      {
         for ( int i = 0; i < chartControl->Legends->Length; i++ )
         {
            if ( i == childID )
            {
               chartControl->Legends[ i ]->Selected = true;
            }
            else
            {
               chartControl->Legends[ i ]->Selected = false;
            }

         }
         
         // AccessibleSelection->AddSelection means that the CurveLegend will be selected.
         if ( (selection & AccessibleSelection::AddSelection) != (AccessibleSelection)0 )
         {
            chartControl->Legends[ childID ]->Selected = true;
         }
         
         // AccessibleSelection->AddSelection means that the CurveLegend will be unselected.
         if ( (selection & AccessibleSelection::RemoveSelection) != (AccessibleSelection)0 )
         {
            chartControl->Legends[ childID ]->Selected = false;
         }
      }
   }

};

// class ChartControlAccessibleObject

// Inner class ChartControlAccessibleObject represents accessible information associated with the ChartControl.
// The ChartControlAccessibleObject is returned in the ChartControl.CreateAccessibilityInstance override.
public class ChartControlAccessibleObject : ControlAccessibleObject
{
    ChartControl chartControl;

    public ChartControlAccessibleObject(ChartControl ctrl) : base(ctrl) 
    {
        chartControl = ctrl;
    }

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

    // Gets the state for the Chart. This is used by accessibility programs.
    public override AccessibleStates State
    {  
        get {                    
            return AccessibleStates.ReadOnly;
        }
    }

    // The CurveLegend objects are "child" controls in terms of accessibility so 
    // return the number of ChartLengend objects.
    public override int GetChildCount()
    {  
        return chartControl.Legends.Length;
    }

    // Gets the Accessibility object of the child CurveLegend idetified by index.
    public override AccessibleObject GetChild(int index)
    {  
        if (index >= 0 && index < chartControl.Legends.Length) {
            return chartControl.Legends[index].AccessibilityObject;
        }                
        return null;
    }

    // Helper function that is used by the CurveLegend's accessibility object
    // to navigate between sibiling controls. Specifically, this function is used in
    // the CurveLegend.CurveLegendAccessibleObject.Navigate function.
    internal AccessibleObject NavigateFromChild(CurveLegend.CurveLegendAccessibleObject child, 
                                                AccessibleNavigation navdir) 
    {  
        switch(navdir) {
            case AccessibleNavigation.Down:
            case AccessibleNavigation.Next:
                return GetChild(child.ID + 1);
                
            case AccessibleNavigation.Up:
            case AccessibleNavigation.Previous:
                return GetChild(child.ID - 1);                        
        }
        return null;
    }

    // Helper function that is used by the CurveLegend's accessibility object
    // to select a specific CurveLegend control. Specifically, this function is used
    // in the CurveLegend.CurveLegendAccessibleObject.Select function.
    internal void SelectChild(CurveLegend.CurveLegendAccessibleObject child, AccessibleSelection selection) 
    {   
        int childID = child.ID;

        // Determine which selection action should occur, based on the
        // AccessibleSelection value.
        if ((selection & AccessibleSelection.TakeSelection) != 0) {
            for(int i = 0; i < chartControl.Legends.Length; i++) {
                if (i == childID) {
                    chartControl.Legends[i].Selected = true;                        
                } else {
                    chartControl.Legends[i].Selected = false;
                }
            }

            // AccessibleSelection.AddSelection means that the CurveLegend will be selected.
            if ((selection & AccessibleSelection.AddSelection) != 0) {
                chartControl.Legends[childID].Selected = true;                        
            }

            // AccessibleSelection.AddSelection means that the CurveLegend will be unselected.
            if ((selection & AccessibleSelection.RemoveSelection) != 0) {
                chartControl.Legends[childID].Selected = false;                        
            }
        }            
    }
}

' Inner Class ChartControlAccessibleObject represents accessible information 
' associated with the ChartControl.
' The ChartControlAccessibleObject is returned in the         ' ChartControl.CreateAccessibilityInstance override.
Public Class ChartControlAccessibleObject
    Inherits Control.ControlAccessibleObject

    Private chartControl As ChartControl
    
    Public Sub New(ctrl As ChartControl)
        MyBase.New(ctrl)
        chartControl = ctrl
    End Sub
    
    ' Get the role for the Chart. This is used by accessibility programs.            
    Public Overrides ReadOnly Property Role() As AccessibleRole
        Get
            Return System.Windows.Forms.AccessibleRole.Chart
        End Get
    End Property
    
    ' Get the state for the Chart. This is used by accessibility programs.            
    Public Overrides ReadOnly Property State() As AccessibleStates
        Get
            Return AccessibleStates.ReadOnly
        End Get
    End Property                        
    
    ' The CurveLegend objects are "child" controls in terms of accessibility so 
    ' return the number of ChartLengend objects.            
    Public Overrides Function GetChildCount() As Integer
        Return chartControl.Legends.Length
    End Function 
    
    ' Get the Accessibility object of the child CurveLegend idetified by index.
    Public Overrides Function GetChild(index As Integer) As AccessibleObject
        If index >= 0 And index < chartControl.Legends.Length Then
            Return chartControl.Legends(index).AccessibilityObject
        End If
        Return Nothing
    End Function 
    
    ' Helper function that is used by the CurveLegend's accessibility object
    ' to navigate between sibiling controls. Specifically, this function is used in
    ' the CurveLegend.CurveLegendAccessibleObject.Navigate function.
    Friend Function NavigateFromChild(child As CurveLegend.CurveLegendAccessibleObject, _
                                    navdir As AccessibleNavigation) As AccessibleObject
        Select Case navdir
            Case AccessibleNavigation.Down, AccessibleNavigation.Next
                    Return GetChild(child.ID + 1)
            
            Case AccessibleNavigation.Up, AccessibleNavigation.Previous
                    Return GetChild(child.ID - 1)
        End Select
        Return Nothing
    End Function            

    ' Helper function that is used by the CurveLegend's accessibility object
    ' to select a specific CurveLegend control. Specifically, this function is used 
    ' in the CurveLegend.CurveLegendAccessibleObject.Select function.            
    Friend Sub SelectChild(child As CurveLegend.CurveLegendAccessibleObject, selection As AccessibleSelection)
        Dim childID As Integer = child.ID
        
        ' Determine which selection action should occur, based on the
        ' AccessibleSelection value.
        If (selection And AccessibleSelection.TakeSelection) <> 0 Then
            Dim i As Integer
            For i = 0 To chartControl.Legends.Length - 1
                If i = childID Then
                    chartControl.Legends(i).Selected = True
                Else
                    chartControl.Legends(i).Selected = False
                End If
            Next i
            
            ' AccessibleSelection.AddSelection means that the CurveLegend will be selected.
            If (selection And AccessibleSelection.AddSelection) <> 0 Then
                chartControl.Legends(childID).Selected = True
            End If

            ' AccessibleSelection.AddSelection means that the CurveLegend will be unselected.                    
            If (selection And AccessibleSelection.RemoveSelection) <> 0 Then
                chartControl.Legends(childID).Selected = False
            End If
        End If
    End Sub
End Class

Remarks

The role of the object describes the function of the object and is used by accessibility applications.

This enumeration is used by AccessibleObject and Control.AccessibleRole

For additional information about the accessibility application, search for "Microsoft Active Accessibility" in the Microsoft Developer Network (MSDN) library.

Applies to

Condividi tramite