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AccessibleNavigation Enumeration

Specifies values for navigating among accessible objects.

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public enum AccessibleNavigation

Member nameDescription
DownNavigation to a sibling object located below the starting object.
FirstChildNavigation to the first child of the object.
LastChildNavigation to the last child of the object.
LeftNavigation to the sibling object located to the left of the starting object.
NextNavigation to the next logical object, typically from a sibling object to the starting object.
PreviousNavigation to the previous logical object, typically from a sibling object to the starting object.
RightNavigation to the sibling object located to the right of the starting object.
UpNavigation to a sibling object located above the starting object.

Accessible navigation directions are either spatial (up, down, left, and right) or logical (first child, last child, next, and previous). Logical directions are used when clients navigate from one user interface element to another within the same container.

AccessibleObject uses this enumeration.

For more information about the accessibility application, search for the "Microsoft Active Accessibility" topic in the MSDN library.

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. 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. 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 AccessibleNavigation enumeration with the Navigate method. 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 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;                        

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0