Flex 4 - 如何从TitleBar皮肤中删除titleText？

Question

我想从titleBar皮肤中删除标题文本，但如果我只是注释掉，我会得到一个错误。我认为这意味着它是必需的皮肤部分？

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

我试着将它设置为text =“”和text =“random text”，但没有效果。如果我在Main应用程序中设置了一个值，但它不适用于空字符串。

现在它显示应用程序名称大概来自“Main-app.xml”文件。

我该如何摆脱它？感谢任何帮助，这实在是烦我......

编辑1：TitleBar中皮肤

<!--- 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> 

应用皮肤代码段：

<!-- 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> 

错误：

[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类中该行上的代码，它看起来像一个错误给我。

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

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

.... 

正如你所看到的，它不检查试图设置其属性text，即使titleText不是必需skinpart之前是否存在titleText。

所以我检查了Adobe JIRA错误数据库。事实证明这个Bug已经提交并仍然没有得到解决：

TitleBar lists titleText as optional, but throws exception when absent

最简单的解决方法，我能想到的是离开titleText标签它在哪里，只是设置其visible和includeInLayout性质到false。