什么是"android:" android-res模块中的前缀均值 [英] What is "android:" prefix mean in android framework-res module

问题描述

我从framework-res模块中的styles.xml文件复制此代码

<style name="Theme">

    <item name="colorForeground">@android:color/bright_foreground_dark</item>
    <item name="colorForegroundInverse">@android:color/bright_foreground_dark_inverse</item>
    <item name="colorBackground">@android:color/background_dark</item>

.

<style name="Theme.Black">
    <item name="android:windowBackground">@android:color/black</item>
    <item name="android:colorBackground">@android:color/black</item>
</style>

如您所见，它们都有一个属性名，其值是windowBackground.但是形式有android:，而后者没有.真的有必要在android框架中写一个android:前缀吗?

解决方案

发现这是一个有趣的问题，并尝试探索以找到答案.

来自: http://developer.android.com/guide/topic/resources/style-resource.html

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style
        name="style_name"
        parent="@[package:]style/style_to_inherit">
        <item
            name="[package:]style_property_name"
            >style_value</item>
    </style>
</resources>

item-为样式定义单个属性.必须是元素的子元素. 属性: 姓名 属性资源.必需的. 要定义的样式属性的名称，必要时带有包前缀(例如android:textColor).

来自: http://developer.android.com/guide/topic/manifest/manifest-intro.html

资源值 一些属性具有可以显示给用户的值，例如，活动的标签和图标.这些属性的值应本地化，因此应从资源或主题中进行设置.资源值以以下格式表示，

@[package:]type:name

，如果资源与应用程序位于同一软件包中，则可以省略软件包名称，其中type是资源的一种类型(例如字符串"或可绘制")，而name是标识特定资源的名称.例如: 主题的值以类似的方式表示，但以?"开头而不是"@":

?[package:]type:name

最后，我尝试在不使用android:的情况下给出属性，尽管编译成功，但它抛出了异常.

I copy the this code from the styles.xml file in framework-res module

<style name="Theme">

    <item name="colorForeground">@android:color/bright_foreground_dark</item>
    <item name="colorForegroundInverse">@android:color/bright_foreground_dark_inverse</item>
    <item name="colorBackground">@android:color/background_dark</item>

.

<style name="Theme.Black">
    <item name="android:windowBackground">@android:color/black</item>
    <item name="android:colorBackground">@android:color/black</item>
</style>

As you see, they all have a attribute name which's value is windowBackground. But the formar has a android: and the latter doesn't. Is it really necessary to write a android: prefix in android framework?

解决方案

Found this to be an interesting question and tried exploring to find the answer.. This is what I found..

from: http://developer.android.com/guide/topics/resources/style-resource.html

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style
        name="style_name"
        parent="@[package:]style/style_to_inherit">
        <item
            name="[package:]style_property_name"
            >style_value</item>
    </style>
</resources>

item - Defines a single property for the style. Must be a child of a element. attributes: name Attribute resource. Required. The name of the style property to be defined, with a package prefix if necessary (for example android:textColor).

from: http://developer.android.com/guide/topics/manifest/manifest-intro.html

Resource values Some attributes have values that can be displayed to users — for example, a label and an icon for an activity. The values of these attributes should be localized and therefore set from a resource or theme. Resource values are expressed in the following format,

@[package:]type:name

where the package name can be omitted if the resource is in the same package as the application, type is a type of resource — such as "string" or "drawable" — and name is the name that identifies the specific resource. For example: Values from a theme are expressed in a similar manner, but with an initial '?' rather than '@':

?[package:]type:name

And finally, I tried giving the attributes without android:, and it threw an exception, though it compiled successfully.

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