Component.CanRaiseEvents 屬性
定義
取得值,指出元件是否能引發事件。Gets a value indicating whether the component can raise an event.
protected:
virtual property bool CanRaiseEvents { bool get(); };
protected virtual bool CanRaiseEvents { get; }
member this.CanRaiseEvents : bool
Protected Overridable ReadOnly Property CanRaiseEvents As Boolean
屬性值
如果元件可以引發事件,則為 true
,否則為 false
。true
if the component can raise events; otherwise, false
. 預設為 true
。The default is true
.
備註
這個屬性的預設實值一律會傳回 true
。The default implementation of this property always returns true
. 繼承自類別的類別 Component 應該覆寫這個屬性,以提供停用引發事件的功能。Classes that inherit from the Component class should override this property to provide the ability to disable the raising of events. 例如,在類別中 Control ,如果控制項是裝載為 activex 控制項,則 CanRaiseEvents false
如果 activex 控制項的事件已凍結,則屬性會傳回。For example, in the Control class, if the control is being hosted as an ActiveX control, the CanRaiseEvents property returns false
if the ActiveX control has its events frozen.
給繼承者的注意事項
如果您在衍生類別中覆寫這個方法,並將其變更為傳回 false
, EventHandlerList 則屬性傳回的集合會 Events null
針對事件傳回。If you override this method in a deriving class and change it to return false
, the EventHandlerList collection returned by the Events property returns null
for an event. 您仍然可以在集合中加入和移除事件,但是集合的 Item[Object] 屬性一律會傳回 null
。Events can still be added and removed from the collection, but the collection's Item[Object] property will always return null
.