attrs文件

<?xml version="1.0" encoding="UTF-8"?>
<resources>
    <!-- attrs属性文件 -->
    <!--declare-styleable里标示的属性可以利用其父属性里的“内容（attr标签里的属性）”满足继承，
    不可利用其他declare·····里的私有内容（attr）,如果需要调用其他declare······里的私有属性，需
    添加引用"（如LinearLayout调用ListView里name="divider"的属性）"：源码☟：
    //表示控件为Listview 
    （1） <declare-styleable name="ListView">
     <attr name="divider" format="reference|color" />
     </declare-styleable>
     //LinearLayout布局控件
     <declare-styleable name="LinearLayout">
     <attr name="divider" />//此为引用（1）控件即ListView控件的私用属性
     </declare-styleable>
     以上两个组件都有共同的最终父类View，所以可以直接利用View里标示的属性“（如他们都可以在xml里用
    padding、background、margin、marginLeft等属性）”，如需引用其他declare-styleable
     内的属性，需在内部添加注明引用，如上所述，其他declare-styleable里的私有属性都可引用，不过需要内部
     注明。 
     -->
     <!-- themes文件和styles文件对attrs中属性的引用,没搞清楚,貌似attrs文件里的属性值
     都可引用，但style时定义控件风格的，theme时定义整个application或activity样式的，作用范围
     不一样 -->
     <!--      ☟以下引用方式通过attr属性
     <item name="dropdownListPreferredItemHeight">
     ?android:attr/listPreferredItemHeightSmall</item>
     直接引用属性值，如果定义多个此属性值，只能友情提示，不能多次第一一个属性值，唯一性，对于一个会报错的，如果你在
     你自定义的风格里设置的话应该会优先调用你自己设置的。
               -----------------------属性唯一性---------------------     
     这个问号引用应该是根据attrs文件下的android:attr/listPreferredItemHeightSmall来遍历所有的有这个
  “属性（listPreferredItemHeightSmall）”的设置，然后就引用这个设置，如果关于这个属性的设置，超过一个，
  android内部应该就判断不了，就报错提示。
  这种一个属性有两个<item name="listPreferredItemHeightSmall">@·····</item>的话，如果直接在另一
  个<item name="dropdownListPreferredItemHeight">
     ?android:attr/listPreferredItemHeightSmall</item>
     属性下引用这个属性的话，应该会报错，唯一性，不报错应该有优先权问题出现，前提是都是?android:attr引用这个下的，
     ?attr/····名字和以上相同没事，不同文件下。
       -->
                     <!-- themes.xml(sdk内部)源码 -->
    <declare-styleable name="WindowAnimation">
        <!-- The animation used when a window is being added. -->
        <attr name="windowEnterAnimation" format="reference" />
        <!-- The animation used when a window is being removed. -->
        <attr name="windowExitAnimation" format="reference" />
        <!-- The animation used when a window is going from INVISIBLE to VISIBLE. -->
        <attr name="windowShowAnimation" format="reference" />
        <!-- The animation used when a window is going from VISIBLE to INVISIBLE. -->
        <attr name="windowHideAnimation" format="reference" />
        </declare-styleable>
        <!-- ListView控件的属性 -->
    <declare-styleable name="ListView">//表示组件为Listview
        <!-- Reference to an array resource that will populate the ListView.  For static content,
             this is simpler than populating the ListView programmatically. -->
        <attr name="entries" />//Listview的引用属性
        <!-- Drawable or color to draw between list items. -->
        <attr name="divider" format="reference|color" />//Listview的私有属性
        <!-- Height of the divider. Will use the intrinsic height of the divider if this
             is not specified. -->
        <attr name="dividerHeight" format="dimension" />
                          <!-- 此处省略 -->
    </declare-styleable>
    
    <!-- 以下列举了View的一部分属性 -->
    <declare-styleable name="View">
        <attr name="visibility">
            <!-- Visible on screen; the default value. -->
            <enum name="visible" value="0" />
            <!-- Not displayed, but taken into account during layout (space is left for it). -->
            <enum name="invisible" value="1" />
            <!-- Completely hidden, as if the view had not been added. -->
            <enum name="gone" value="2" />
        </attr>
        <!-- Sets the padding, in pixels, of the left edge; see {@link android.R.attr#padding}. -->
        <attr name="paddingLeft" format="dimension" />
        <!-- Sets the padding, in pixels, of the top edge; see {@link android.R.attr#padding}. -->
        <attr name="paddingTop" format="dimension" />
        <!-- Sets the padding, in pixels, of the right edge; see {@link android.R.attr#padding}. -->
        <attr name="paddingRight" format="dimension" />
        <!-- Sets the padding, in pixels, of the bottom edge; see {@link android.R.attr#padding}. -->
        <attr name="paddingBottom" format="dimension" />
        </declare-styleable>
         <!-- Standard orientation constant. -->
         <!-- Theme的一部分属性 -->
         <declare-styleable name="Theme">
    <attr name="orientation">
        <!-- Defines an horizontal widget. -->
        <enum name="horizontal" value="0" />//orientation的元素（值）
        <!-- Defines a vertical widget. -->
        <enum name="vertical" value="1" />
    </attr>
    </declare-styleable>
    <!-- 以下为LinearLayout的一部分属性 -->
     <declare-styleable name="LinearLayout">
        <!-- Should the layout be a column or a row?  Use "horizontal"
             for a row, "vertical" for a column.  The default is
             horizontal. -->
        <attr name="orientation" /><!-- 引用<declare-styleable name="Theme">的属性 -->
        <attr name="gravity" />
        <attr name="divider" />//对listview私有属性的引用
        <!-- Defines the maximum weight sum. If unspecified, the sum is computed
             by adding the layout_weight of all of the children. This can be
             used for instance to give a single child 50% of the total available
             space by giving it a layout_weight of 0.5 and setting the weightSum
             to 1.0. -->
        <attr name="weightSum" format="float" />
        <!-- When set to true, all children with a weight will be considered having
             the minimum size of the largest child. If false, all children are
             measured normally. -->
        <attr name="measureWithLargestChild" format="boolean" />
                                <!-- 此处省略 -->
    </declare-styleable>
    
    <eat-comment />
    <attr name="orientation">
        <!-- Defines an horizontal widget. -->
        <enum name="horizontal" value="0" />
        <!-- Defines a vertical widget. -->
        <enum name="vertical" value="1" />
    </attr>
    <eat-comment />
     <attr name="gravity">
        <!-- Push object to the top of its container, not changing its size. -->
        <flag name="top" value="0x30" />//gravity的可选值
        <!-- Push object to the bottom of its container, not changing its size. -->
        <flag name="bottom" value="0x50" />
        <!-- Push object to the left of its container, not changing its size. -->
        <flag name="left" value="0x03" />
        <!-- Push object to the right of its container, not changing its size. -->
        <flag name="right" value="0x05" />
        <!-- Place object in the vertical center of its container, not changing its size. -->
                                   <!-- 此处省略 -->
        <!-- Push object to the beginning of its container, not changing its size. -->
        <flag name="start" value="0x00800003" />
        <!-- Push object to the end of its container, not changing its size. -->
        <flag name="end" value="0x00800005" />
    </attr>
</resources>