Flex 4 - 如何從TitleBar皮膚中刪除titleText？

Question

我想從titleBar皮膚中刪除標題文本，但如果我只是註釋掉，我會得到一個錯誤。我認爲這意味着它是必需的皮膚部分？

<!-- title --> 
<!--- @copy spark.components.windowClasses.TitleBar#titleText --> 
<s:Label id="titleText" minWidth="0" maxDisplayedLines="1" width="100%" /> 

我試着將它設置爲text =「」和text =「random text」，但沒有效果。如果我在Main應用程序中設置了一個值，但它不適用於空字符串。

現在它顯示應用程序名稱大概來自「Main-app.xml」文件。

我該如何擺脫它？感謝任何幫助，這實在是煩我......

編輯1：TitleBar中皮膚

<!--- The default skin class for the title bar of the Spark WindowedApplication component 
     and Spark Window component when you use Flex chrome. 
     The title bar skin includes the close, minimize, and maximize buttons, the 
     title icon, and the title text. 

     <p>The Flex chrome is defined by the SparkChromeWindowedApplicationSkin skin class 
     in the spark.skins.spark package. 
     To use the Flex chrome, set <code>systemChrome</code> to "none" in the application's .xml file, 
     and set the <code>skinClass</code> style to spark.skins.spark.SparkChromeWindowedApplicationSkin. </p> 

     @langversion 3.0 
     @playerversion Flash 10 
     @playerversion AIR 1.5 
     @productversion Flex 4 

     @see spark.components.WindowedApplication 
     @see spark.components.Window 
     @see spark.skins.spark.SparkChromeWindowedApplicationSkin 


    This Skin is based on "TitleBar"; 
--> 
<s:SparkSkin xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark" 
      xmlns:fb="http://ns.adobe.com/flashbuilder/2009" xmlns:mx="library://ns.adobe.com/flex/mx" 
      minHeight="40" creationComplete="created()" > 

    <fx:Metadata> 
     [HostComponent("spark.components.windowClasses.TitleBar")] 
    </fx:Metadata> 

    <fx:Script fb:purpose="styling"> 


     import mx.core.FlexGlobals; 
     import mx.events.StateChangeEvent; 

     /* Exclude the titleBar and scroller because they are SparkSkins and we 
     * don't want to colorize them twice. */ 
     static private const exclusions:Array = ["titleBar"]; 

     override public function get colorizeExclusions():Array 
     { 
      return exclusions; 
     } 

     override protected function initializationComplete():void 
     { 
      useChromeColor = true; 
      super.initializationComplete(); 
     } 

     public var ifo:Boolean; 

     public function created():void 
     { 
      this.hostComponent.parentApplication.addEventListener(StateChangeEvent.CURRENT_STATE_CHANGE, buttonToggle); 
     } 

     override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void 
     { 
      //trace(hostComponent.parentApplication.currentState); 
      backgroundRect.radiusX = getStyle("cornerRadius"); 

      super.updateDisplayList(unscaledWidth, unscaledHeight); 
     } 

     private function returnButtonHandler(event:MouseEvent):void 
     { 
      this.hostComponent.parentApplication.currentState = "Home"; 
     } 

     private var lastState:String; 

     private function buttonToggle(event:StateChangeEvent):void 
     { 
      lastState = event.oldState; 

      if(event.newState == "Home") 
      { 
       returnButton.visible = false; 
       settingsButton.label = "Settings"; 
      } 
      else if(event.newState == "MoviePage") 
      { 
       returnButton.visible = true; 
       settingsButton.label = "Settings"; 
      } 
      else 
      { 
       returnButton.visible = false; 
       settingsButton.label = "Back"; 
      } 
     } 

     private function settingsButtonHandler(event:MouseEvent):void 
     { 
      if(settingsButton.label == "Settings") // if button label is settings 
      { 
       hostComponent.parentApplication.currentState = "Settings"; 
      } 
      else // if button label is back 
      { 
       hostComponent.parentApplication.currentState = lastState; // return to previous state 
      } 
     } 

    </fx:Script> 

    <s:states> 
     <s:State name="normal" /> 
     <s:State name="disabled" /> 
     <s:State name="normalAndMaximized" stateGroups="maximizedGroup" /> 
     <s:State name="disabledAndMaximized" stateGroups="maximizedGroup" /> 
    </s:states> 

    <!-- fill --> 
    <!--- Defines the background color of the title bar. --> 
    <s:Rect id="backgroundRect" left="0" right="0" top="0" bottom="0" > 
     <s:fill> 
      <s:LinearGradient id="bgFill" rotation="90"> 
       <s:GradientEntry color="0xFFFFFF" /> 
       <s:GradientEntry color="0xBABABA" /> 
      </s:LinearGradient> 
     </s:fill> 
    </s:Rect> 

    <!-- title bar content --> 
    <s:Group id="titleBar" minHeight="40" width="100%" height="100%" left="3" right="2" > 
     <s:layout> 
      <s:HorizontalLayout verticalAlign="middle" gap="5" /> 
     </s:layout> 

     <!-- title bar icon --> 
     <!--- @copy spark.components.windowClasses.TitleBar#titleIconImage --> 
     <s:BitmapImage id="titleIconImage" minWidth="0" fillMode="clip"/> 

     <!-- return button --> 
     <s:Button id="returnButton" label="Return" click="returnButtonHandler(event)" visible="false" /> 

     <!-- title --> 
     <!--- @copy spark.components.windowClasses.TitleBar#titleText --> 
     <s:Label id="titleText" visible="false" includeInLayout="false" minWidth="0" maxDisplayedLines="1" width="100%" /> !!!!!!!! Error if this line is deleted !!!!!!!!! 

     <!-- settings/back button --> 
     <s:Button id="settingsButton" label="Settings" click="settingsButtonHandler(event)" visible="true" /> 

     <!-- minimize button --> 
     <!--- 
      By default, the button uses the spark.skins.spark.windowChrome.MinimizeButtonSkin class 
      to define the skin for the mimimized button. 
      @copy spark.components.windowClasses.TitleBar#minimizeButton 
      @see spark.skins.spark.windowChrome.MinimizeButtonSkin 
     --> 
     <s:Button id="minimizeButton" verticalCenter="0" 
      skinClass="skins.CustomMinimizeButtonSkin" /> 

     <!-- maximize button --> 
     <!--- 
      By default, the button uses the spark.skins.spark.windowChrome.MinimizeButtonSkin class 
      to define the skin for the maximized button. 
      @copy spark.components.windowClasses.TitleBar#maximizeButton 
      @see spark.skins.spark.windowChrome.MaximizeButtonSkin 
     --> 
     <s:Button id="maximizeButton" verticalCenter="0" 
        skinClass="skins.CustomMaximizeButtonSkin" 
        skinClass.maximizedGroup="skins.CustomRestoreButtonSkin" /> 

     <!-- close button --> 
     <!--- 
      By default, the button uses the spark.skins.spark.windowChrome.MinimizeButtonSkin class 
      to define the skin for the close button. 
      @copy spark.components.windowClasses.TitleBar#closeButton 
      @see spark.skins.spark.windowChrome.CloseButtonSkin 
     --> 
     <s:Button id="closeButton" verticalCenter="0" 
      skinClass="skins.CustomCloseButtonSkin" /> 
     <s:Spacer /> 

    </s:Group> 

</s:SparkSkin> 

應用皮膚代碼段：

<!-- layer 3: title bar + content --> 
    <s:Group left="0" right="0" top="0" bottom="0" minHeight="0" minWidth="0" > 
     <s:layout> 
      <s:VerticalLayout gap="0"/> 
     </s:layout> 

     <!-- title bar --> 
     <s:TitleBar id="titleBar" width="100%" minHeight="40" skinClass="skins.CustomTitleBarSkin" /> 

     <!-- content --> 
     <s:Group id="contentGroup" width="100%" height="100%" minHeight="0" minWidth="0" /> 

    </s:Group> 

    <!-- layer 4: gripper --> 
    <!--- @see spark.skins.spark.windowChrome.GripperSkin --> 
    <s:Button id="gripper" right="6" bottom="5" tabEnabled="false" 
       skinClass="spark.skins.spark.windowChrome.GripperSkin" /> 

</s:SparkSkin> 

錯誤：

[SWF] Main.swf - 5,439,008 bytes after decompression 
TypeError: Error #1009: Cannot access a property or method of a null object reference. 
    at spark.components.windowClasses::TitleBar/commitProperties()[E:\dev\4.y\frameworks\projects\airspark\src\spark\components\windowClasses\TitleBar.as:443] 
    at mx.core::UIComponent/validateProperties()[E:\dev\4.y\frameworks\projects\framework\src\mx\core\UIComponent.as:8219] 
    at mx.managers::LayoutManager/validateProperties()[E:\dev\4.y\frameworks\projects\framework\src\mx\managers\LayoutManager.as:597] 
    at mx.managers::LayoutManager/doPhasedInstantiation()[E:\dev\4.y\frameworks\projects\framework\src\mx\managers\LayoutManager.as:783] 
    at mx.managers::LayoutManager/doPhasedInstantiationCallback()[E:\dev\4.y\frameworks\projects\framework\src\mx\managers\LayoutManager.as:1180] 

Answer 1

我只是看看TitleBar類中該行上的代碼，它看起來像一個錯誤給我。

override protected function commitProperties():void { 
    super.commitProperties(); 

    if (titleChanged) { 
     titleText.text = _title; 
     titleChanged = false; 
    } 

.... 

正如你所看到的，它不檢查試圖設置其屬性text，即使titleText不是必需skinpart之前是否存在titleText。

所以我檢查了Adobe JIRA錯誤數據庫。事實證明這個Bug已經提交併仍然沒有得到解決：

TitleBar lists titleText as optional, but throws exception when absent

最簡單的解決方法，我能想到的是離開titleText標籤它在哪裏，只是設置其visible和includeInLayout性質到false。