ToolStripItem.QueryAccessibilityHelp ToolStripItem.QueryAccessibilityHelp ToolStripItem.QueryAccessibilityHelp ToolStripItem.QueryAccessibilityHelp Event

定义

当具有辅助功能的客户端应用程序调用 ToolStripItem 的帮助时发生。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 

示例

下面的代码示例演示如何使用此成员。The following code example demonstrates the use of this member. 在此示例中, 事件处理程序报告QueryAccessibilityHelp事件的发生。In the example, an event handler reports on the occurrence of the QueryAccessibilityHelp event. 此报表可帮助你了解何时发生事件, 并可帮助你进行调试。This report helps you to learn when the event occurs and can assist you in debugging. 若要报告多个事件或频繁发生的事件, 请考虑MessageBox.ShowConsole.WriteLine消息替换为多行或将TextBox其追加到多行。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.

若要运行示例代码, 请将其粘贴到一个项目中, 该项目包含从ToolStripItem继承的类型的实例, 如ToolStripMenuItem ToolStripButton或。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. 然后命名该实例ToolStripItem1 , 并确保事件处理程序QueryAccessibilityHelp与事件相关联。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

注解

你应使用HelpProvider类来允许用户通过按 F1 键来调用辅助性对象上的帮助。You should use the HelpProvider class to allow users to invoke help on your accessible object by pressing the F1 key. 使用可以QueryAccessibilityHelpEventArgs在对象中HelpProvider提供完整信息。Using the HelpProvider provides you with complete information in the QueryAccessibilityHelpEventArgs object.

有关处理事件的详细信息, 请参阅处理和引发事件For more information about handling events, see Handling and Raising Events.

适用于