ToolStripItem.QueryAccessibilityHelp Event

Definition

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Source:

ToolStripItem.cs

Occurs when an accessibility client application invokes help for the ToolStripItem.

public:
 event System::Windows::Forms::QueryAccessibilityHelpEventHandler ^ QueryAccessibilityHelp;

public event System.Windows.Forms.QueryAccessibilityHelpEventHandler? QueryAccessibilityHelp;

member this.QueryAccessibilityHelp : System.Windows.Forms.QueryAccessibilityHelpEventHandler 

Public Custom Event QueryAccessibilityHelp As QueryAccessibilityHelpEventHandler 

Event Type

QueryAccessibilityHelpEventHandler

Examples

The following code example demonstrates the use of this member. In the example, an event handler reports on the occurrence of the QueryAccessibilityHelp event. This report helps you to learn when the event occurs and can assist you in debugging. To report on multiple events or on events that occur frequently, consider replacing MessageBox.Show with Console.WriteLine or appending the message to a multiline TextBox.

To run the example code, paste it into a project that contains an instance of a type that inherits from ToolStripItem, such as a ToolStripButton or ToolStripMenuItem. Then name the instance ToolStripItem1 and ensure that the event handler is associated with the QueryAccessibilityHelp event.

private void ToolStripItem1_QueryAccessibilityHelp(Object sender, QueryAccessibilityHelpEventArgs e) {

System.Text.StringBuilder messageBoxCS = new System.Text.StringBuilder();
messageBoxCS.AppendFormat("{0} = {1}", "HelpNamespace", e.HelpNamespace );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "HelpString", e.HelpString );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "HelpKeyword", e.HelpKeyword );
messageBoxCS.AppendLine();
MessageBox.Show(messageBoxCS.ToString(), "QueryAccessibilityHelp Event" );
}

Private Sub ToolStripItem1_QueryAccessibilityHelp(sender as Object, e as QueryAccessibilityHelpEventArgs) _ 
     Handles ToolStripItem1.QueryAccessibilityHelp

    Dim messageBoxVB as New System.Text.StringBuilder()
    messageBoxVB.AppendFormat("{0} = {1}", "HelpNamespace", e.HelpNamespace)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "HelpString", e.HelpString)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "HelpKeyword", e.HelpKeyword)
    messageBoxVB.AppendLine()
    MessageBox.Show(messageBoxVB.ToString(),"QueryAccessibilityHelp Event")

End Sub

Remarks

You should use the HelpProvider class to allow users to invoke help on your accessible object by pressing the F1 key. Using the HelpProvider provides you with complete information in the QueryAccessibilityHelpEventArgs object.

For more information about handling events, see Handling and Raising Events.