UIElement.PreviewMouseDown 事件
定義
指標在此元素上方且按下任何滑鼠按鈕時發生。Occurs when any mouse button is pressed while the pointer is over this element.
public:
event System::Windows::Input::MouseButtonEventHandler ^ PreviewMouseDown;public event System.Windows.Input.MouseButtonEventHandler PreviewMouseDown;member this.PreviewMouseDown : System.Windows.Input.MouseButtonEventHandler Public Custom Event PreviewMouseDown As MouseButtonEventHandler 事件類型
備註
此事件 Mouse.PreviewMouseDown 會為這個類別建立附加事件的別名，因此 PreviewMouseDown 當 UIElement 繼承為基底專案時，它就是類別成員清單的一部分。This event creates an alias for the Mouse.PreviewMouseDown attached event for this class, so that PreviewMouseDown is part of the class members list when UIElement is inherited as a base element. 附加至事件的事件處理常式 PreviewMouseDown 會附加至基礎 Mouse.PreviewMouseDown 附加事件，並接收相同的事件資料實例。Event handlers that are attached to the PreviewMouseDown event are attached to the underlying Mouse.PreviewMouseDown attached event and receive the same event data instance.
PreviewMouseDown事件通常會與或一起引發 PreviewMouseLeftButtonDown PreviewMouseRightButtonDown ，這會對應至兩個標準滑鼠按鍵的其中一個。The PreviewMouseDown event is often raised together with either PreviewMouseLeftButtonDown or PreviewMouseRightButtonDown, which correspond to a press of one of the two standard mouse buttons. PreviewMouseLeftButtonDown 和 PreviewMouseRightButtonDown 也是路由事件，但它們是直接路由事件，而且當 Mouse.PreviewMouseDown 事件到達事件路由的這個專案時，就會引發適當的按鈕特定事件。PreviewMouseLeftButtonDown and PreviewMouseRightButtonDown are also routed events, but they are direct routed events, and the appropriate button-specific event is raised when the Mouse.PreviewMouseDown event reaches this element along the event route. 請參閱或的備註 PreviewMouseLeftButtonDown PreviewMouseRightButtonDown 。See Remarks for PreviewMouseLeftButtonDown or PreviewMouseRightButtonDown.
路由事件資訊Routed Event Information
| 識別碼欄位Identifier field | PreviewMouseDownEvent |
| 路由策略Routing strategy | 隧道Tunneling |
| 代理人Delegate | MouseButtonEventHandler |
對應的反升事件為 MouseDown 。The corresponding bubbling event is MouseDown.
OnPreviewMouseDown在衍生類別中覆寫以執行這個事件的類別處理。Override OnPreviewMouseDown to implement class handling for this event in derived classes.