接收Flash中的Event.COPY事件

Question

我的目標是知道用戶何時按下剪切，複製，粘貼或選擇所有鍵盤快捷方式併爲每個鍵盤快捷鍵執行一些處理。我試着聽按鍵，但只有一些鍵在控制鍵關閉時觸發（顯然它只能在瀏覽器中工作，IE除外）。

然後，我正在閱讀Flash文檔，並遇到了分配給「當前具有焦點的對象」的Event.COPY,Event.PASTE和Event.CUT事件。我將這些事件的監聽器附加到文檔類中，並將stage.focus設置爲文檔類，但我的事件監聽器從未被調用。

有沒有人使用過這些事件？有沒有關於如何使用它們的例子？

注意：這是在Flash Player 10（內部CS4之一（禁用「禁用快捷方式」）和獨立的一個）。我沒有在任何瀏覽器中嘗試過。

Answer 1

除了可以從TextFields捕獲這些事件的限制（或焦點位於TextField上時），請確保stage.focus屬性確實設置爲您將偵聽器附加到的InteractiveObject，或者任何它的孩子（除非它是一個textfield ^^）。

記住，你只能將焦點設置通過直接設置Stage.focus屬性，並通過點擊或Tab鍵在查看tabEnabled InteractiveObjects。

Answer 2

爲了完整起見，下面是我最終使用的類，它允許焦點轉到「白名單」上的幾個對象，然後在焦點從對象中丟失時將焦點恢復爲默認對象。白名單的對象（除非將另一白名單的對象）：

/* 
Copyright (c) 2009, Cameron Desrochers 
All rights reserved. 

Redistribution and use in source and binary forms, with or without modification, are permitted 
provided that the following conditions are met: 

    * Redistributions of source code must retain the above copyright notice, this list of 
     conditions and the following disclaimer. 
    * Redistributions in binary form must reproduce the above copyright notice, this list 
     of conditions and the following disclaimer in the documentation and/or other materials 
     provided with the distribution. 

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR 
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
*/ 


package 
{ 
    import fl.controls.ColorPicker; 
    import flash.display.DisplayObject; 
    import flash.display.InteractiveObject; 
    import flash.display.DisplayObjectContainer; 
    import flash.display.Sprite; 
    import flash.display.Stage; 
    import flash.events.Event; 
    import flash.events.FocusEvent; 
    import flash.events.MouseEvent; 
    import flash.geom.Point; 
    import flash.utils.Dictionary; 



    public class FocusManager 
    { 
     public static var stage:Stage; 
     public static var defaultFocalObject:DisplayObjectContainer; 

     private static var _whiteList:Array = new Array(); 


     public static function init(stage:Stage, defaultFocalObject:DisplayObjectContainer):void 
     { 
      FocusManager.stage = stage; 
      FocusManager.defaultFocalObject = defaultFocalObject; 

      stage.addEventListener(MouseEvent.CLICK, onStageClicked); 

      defaultFocalObject.addEventListener(FocusEvent.FOCUS_OUT, onObjectFocusOut); 

      restoreDefaultFocus(); 
     } 


     public static function restoreDefaultFocus():void 
     { 
      stage.focus = defaultFocalObject; 
     } 


     public static function addToWhiteList(object:InteractiveObject):void 
     { 
      if (Object(object).constructor == ColorPicker) {  // Special case 
       // ColorPicker objects possess a textField that is for some reason not a child of the 
       // ColorPicker, and so the textField has to be added separately. 

       addToWhiteList(ColorPicker(object).textField); 
      } 

      _whiteList.push(object); 

      object.addEventListener(FocusEvent.FOCUS_OUT, onObjectFocusOut); 
      object.addEventListener(Event.REMOVED_FROM_STAGE, onObjectRemovedFromStage); 
     } 


     private static function onObjectFocusOut(e:FocusEvent):void 
     { 
      //trace('e.target:', e.target); 
      //trace('e.relatedObject:', e.relatedObject); 

      if ((e.relatedObject == null) || ((e.relatedObject !== defaultFocalObject) && (!whiteListContains(e.relatedObject)))) { 
       // Object that is gaining focus is not in white-list, restore focus: 

       //trace('restoring default focus'); 
       restoreDefaultFocus(); 
      } 
     } 


     private static function whiteListContains(object):Boolean 
     { 
      var inList:Boolean = false; 

      for each (var listItem in _whiteList) { 
       if ((object === listItem) || ((listItem.hasOwnProperty('contains')) && (listItem.contains(object)))) { 
        inList = true; 
        break; 
       } 
      } 

      return inList; 
     } 


     private static function onObjectRemovedFromStage(e:Event):void 
     { 
      restoreDefaultFocus(); 
     } 


     private static function onStageClicked(e:MouseEvent):void 
     { 
      var objectsUnderClick:Array = stage.getObjectsUnderPoint(new Point(stage.mouseX, stage.mouseY)); 

      var clickedOnWhiteListItem:Boolean = false; 
      for each (var object in objectsUnderClick) { 
       if (whiteListContains(object)) { 
        clickedOnWhiteListItem = true; 
        break; 
       } 
      } 

      if (!clickedOnWhiteListItem) { 
       restoreDefaultFocus(); 
      } 
     } 
    } 
} 

調用靜態init方法與文檔類的stage對象和對象，你想重點在默認情況下返回。然後用靜態的addToWhitelist方法將對象添加到白名單中。