ContentElement.PreviewLostKeyboardFocus 事件
定义
在此元素不再聚焦于键盘时发生。Occurs when the keyboard is no longer focused on this element.
public:
virtual event System::Windows::Input::KeyboardFocusChangedEventHandler ^ PreviewLostKeyboardFocus;public event System.Windows.Input.KeyboardFocusChangedEventHandler PreviewLostKeyboardFocus;member this.PreviewLostKeyboardFocus : System.Windows.Input.KeyboardFocusChangedEventHandler Public Custom Event PreviewLostKeyboardFocus As KeyboardFocusChangedEventHandler 事件类型
实现
注解
由于此事件使用隧道路由，失去焦点的元素可能是子元素，而不是实际附加事件处理程序的元素。Because this event uses tunneling routing, the element that lost focus might be a child element instead of the element where the event handler is actually attached. 检查 Source 事件数据中的，以确定失去焦点的实际元素。Check the Source in the event data to determine the actual element that lost focus.
此事件将为 Keyboard.PreviewLostKeyboardFocus 此类创建附加事件的别名，因此 PreviewLostKeyboardFocus 当 ContentElement 继承为基元素时，它是类成员列表的一部分。This event creates an alias for the Keyboard.PreviewLostKeyboardFocus attached event for this class, so that PreviewLostKeyboardFocus is part of the class members list when ContentElement is inherited as a base element. 附加到事件的事件处理程序 PreviewLostKeyboardFocus 附加到基础 Keyboard.PreviewLostKeyboardFocus 附加事件，并接收相同的事件数据实例。Event handlers that are attached to the PreviewLostKeyboardFocus event are attached to the underlying Keyboard.PreviewLostKeyboardFocus attached event and receive the same event data instance.
路由事件信息Routed Event Information
| 标识符字段Identifier field | PreviewLostKeyboardFocusEvent |
| 路由策略Routing strategy | 隧道Tunneling |
| 委托Delegate | KeyboardFocusChangedEventHandler |
对应的冒泡事件为 LostKeyboardFocus 。The corresponding bubbling event is LostKeyboardFocus.
重写 OnPreviewLostKeyboardFocus 以在派生类中实现此事件的类处理。Override OnPreviewLostKeyboardFocus to implement class handling for this event in derived classes.