Flex - 与皮肤风格

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什么是剥皮？

• Flex 中的换肤是完全自定义 UI 组件外观的过程。

• 皮肤可以定义组件的文本、图像、过滤器、转换和状态。

• 皮肤可以创建为单独的 mxml 或 ActionScript 组件。

• 使用皮肤，我们可以控制 UI 组件的所有视觉方面。

• 对于所有 UI 组件来说，定义皮肤的过程都是相同的。

第 1 步 – 创建皮肤

使用选项File > New > MXML Skin启动创建 MXML Skin 向导。

输入 Package 为com.tutorialspoint.skin，名称为GradientBackgroundSkin，然后选择宿主组件作为现有的 flex BorderContainer 控件spark.component.BorderContainer。

现在您已经为 BorderContainer 创建了外观。修改 mxml 皮肤文件src/com.tutorialspoint/skin/GradientBackgroundSkin.mxml的内容。

更新填充层如下 -

<!-- fill -->
<s:Rect id = "backgroundRect" left = "0" right = "0" height = "100%" top = "0">
   <s:fill>
      <s:LinearGradient rotation = "90">
         <s:GradientEntry color = "0x888888" ratio = "0.2" />
         <s:GradientEntry color = "0x111111" ratio = "1" />
      </s:LinearGradient>
   </s:fill>
</s:Rect>	

第 2 步：涂抹皮肤

您可以通过两种方式在组件上应用皮肤 -

在 MXML 脚本中应用皮肤（静态）

使用其SkinClass属性将GradientBackgroundSkin应用于 ID 为mainContainer 的BorderContainer 。

<s:BorderContainer width = "560" height = "500" id = "mainContainer" 
   styleName = "container">
   <s:VGroup width = "100%" height = "100%" gap = "50" 
      horizontalAlign = "center" verticalAlign = "middle" 
      skinClass = "com.tutorialspoint.skin.GradientBackgroundSkin">

在 ActionScript 中应用皮肤（动态）

使用其SkinClass属性将GradientBackgroundSkin应用于 ID 为mainContainer 的BorderContainer 。

protected function gradientBackground_clickHandler(event:MouseEvent):void {
   mainContainer.setStyle("skinClass", GradientBackgroundSkin);
}

Flex 样式与皮肤示例

让我们按照以下步骤通过创建一个测试应用程序来查看 Flex 应用程序中的换肤效果 -

以下是 GradientBackgroundSkin.mxml 文件src/com/tutorialspoint/skin/GradientBackg roundSkin.mxml的内容。

<?xml version = "1.0" encoding = "utf-8"?>
<s:Skin xmlns:fx = "http://ns.adobe.com/mxml/2009" 
   xmlns:s = "library://ns.adobe.com/flex/spark" 
   xmlns:mx = "library://ns.adobe.com/flex/mx">
   
   <!-- host component -->
   <fx:Metadata>
      [HostComponent("spark.components.BorderContainer")]
   </fx:Metadata> 

   <!-- states -->
   <s:states>
      <s:State name = "disabled" />
      <s:State name = "disabled" />
      <s:State name = "normal" />
   </s:states>

   <!-- SkinParts
   name = contentGroup, type = spark.components.Group, required = false
   -->
   
   <!-- fill -->
   <s:Rect id = "backgroundRect" left = "0" right = "0" height = "100%" top = "0">
      <s:fill>
         <s:LinearGradient rotation = "90">
            <s:GradientEntry color = "0x111111" ratio = "0.2" />
            <s:GradientEntry color = "0x888888" ratio = "1" />
         </s:LinearGradient>
      </s:fill>
   </s:Rect>	
   
   <!-- must specify this for the host component --> 
   <s:Group id = "contentGroup" left = "0" right = "0" top = "0" bottom = "0" />
</s:Skin>

以下是修改后的 HelloWorld.mxml 文件的内容rc/com/tutorialspoint/client/HelloWorld.mxml。

<?xml version = "1.0" encoding = "utf-8"?>
<s:Application xmlns:fx = "http://ns.adobe.com/mxml/2009"
   xmlns:s = "library://ns.adobe.com/flex/spark"
   xmlns:mx = "library://ns.adobe.com/flex/mx"
   width = "100%" height = "100%" minWidth = "500" minHeight = "500"
   initialize = "application_initializeHandler(event)">

   <fx:Style source = "/com/tutorialspoint/client/Style.css" />
   <fx:Script>
      <![CDATA[
         import com.tutorialspoint.skin.GradientBackgroundSkin;
         import mx.controls.Alert;
         import mx.events.FlexEvent;
         import spark.skins.spark.BorderContainerSkin;			

         protected function btnClickMe_clickHandler(event:MouseEvent):void {
            Alert.show("Hello World!");				
         }

         protected function application_initializeHandler(event:FlexEvent):void {
            lblHeader.text = "My Hello World Application";				
         }

         protected function gradientBackground_clickHandler(event:MouseEvent):void {
            mainContainer.setStyle("skinClass", GradientBackgroundSkin );
         }

         protected function standardBackground_clickHandler(event:MouseEvent):void {
            mainContainer.setStyle("skinClass", BorderContainerSkin );
         }
      ]]>
   </fx:Script>
   
   <fx:Declarations>
      <s:RadioButtonGroup id = "selectorGroup" />
   </fx:Declarations>
   
   <s:BorderContainer width = "500" height = "500" id = "mainContainer"
      skinClass = "spark.skins.spark.BorderContainerSkin" 
      horizontalCenter = "0" verticalCenter = "0" cornerRadius = "10">
      
      <s:VGroup width = "100%" height = "100%" gap = "50" horizontalAlign = "center"
         verticalAlign = "middle">
         <s:Label id = "lblHeader" fontSize = "40" color = "green" 
            styleName = "heading" />
         <s:Button label = "Click Me!" id = "btnClickMe" 
            click = "btnClickMe_clickHandler(event)" />
         <s:RadioButton color = "gray" fontWeight = "bold" 
            group = "{selectorGroup}" label = "Standard Background" 
            click = "standardBackground_clickHandler(event)" selected = "true" />
         <s:RadioButton color = "gray" fontWeight = "bold" 
            group = "{selectorGroup}" label = "Gradient Background" 
            click = "gradientBackground_clickHandler(event)" />			
      </s:VGroup>			
   </s:BorderContainer>	
</s:Application>

准备好完成所有更改后，让我们在正常模式下编译并运行应用程序，就像我们在Flex - 创建应用程序一章中所做的那样。如果您的应用程序一切正常，它将产生以下结果：[在线尝试]