未绑定元素的前缀 [英] Prefix for element not bound

问题描述

我是 Flex 开发的新手，正在使用 Flash Builder 4 和 SDK 4.现在我在第 4 行收到未绑定元素fx:Style"的前缀fx"的错误.我搜索了它，它有……与命名空间有关，但我自己无法解决.

I am a newbie in Flex development and using Flash Builder 4 with SDK 4. Now I get the error that "the prefix "fx" for element "fx:Style" is not bound" in line number 4. I searched for it, and it has sth. to do with namespaces, but I can not solve it by myelf.

我在目录components"中有名为UserStory.mxml"的文件，通过main.mxml将其放置到屏幕上:

I have the file called "UserStory.mxml" in the directory "components" to place it via the main.mxml onto the screen:

<fx:Script>
    <![CDATA[
        import components.UserStory;
        private function init():void {
            var userStory1:UserStory = new UserStory();
            userStory1.x = 100;
            userStory1.y = 100;

            userStory1.userStoryText = "test";

            this.addChild(userStory1);
        }
    ]]>
</fx:Script>

第 1 行出现错误的文件.4:

The file in which the error occurs in line no. 4:

<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml" width="300" height="150" styleName="userstory">

    <fx:Style source="styles/styles.css"/>

    <fx:Text x="5" y="5" width="275" height="135" text="{userStoryText}" fontFamily="notes" fontSize="18"/>

    <mx:Script>
        ...
    </mx:Script>
</mx:Canvas>

谁能告诉我怎么了?

推荐答案

正如您怀疑是命名空间的问题.MXML 只是 XML，在 XML 中，您可以定义命名空间并将它们绑定到 URL.命名空间是 XML 元素冒号之前的部分，通常在封闭元素上定义.

As you suspected it is a problem with the namespace. MXML is just XML and in XML you can define namespaces and bind them to a URL. The namespaces are the part before the colon of an XML element and are usually defined on the enclosing element.

如果您查看 MXML 文件，您会看到 mx 命名空间的一个命名空间声明:

If you look at your MXML file you'll see one namespace declaration for the mx namespace:

<mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml" ...

fx 的声明丢失了，这就是编译器所抱怨的.添加适当的定义，您应该没问题(请参阅 此页面更多详情):

The declaration for fx is missing and that's what the compiler complains about. Add the appropriate definition and you should be fine (see this page for more details):

<mx:Canvas xmlns:fx="http://ns.adobe.com/mxml/2009" ...

此外，如果您使用的是 Flex 4，您应该查看该文件，因为 mx:Canvas 是一个 Flex 3 组件，因此不能直接在 Flex 4 应用程序中使用.看看 API用于 Flex 4 SDK 的 Canvas 文档.

Also, if you are using Flex 4 you should review the file as mx:Canvas is a Flex 3 component and as such not directly usable in Flex 4 apps. Have a look at the API docs of Canvas for the Flex 4 SDK.

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