多个类定义attr属性重复的问题:Attribute ＂xxx＂ has already been defined

有时候做自定义控件时就会遇到命名冲突，改变有冲突的名字自然是最直接有效的方式，但是感觉很傻。我搜了下别人的解决方案，觉得很值得借鉴。就是把重名的属性，独立出来写一下，然后在定义时直接写属性名字即可。

比如：下面两个declare-styleable中icon重名了，我们就需要将icon独立出来写。

<? xml version = "1.0" encoding = "utf-8" ?>
< resources >
     < declare-styleable name= "PreferenceHeader" >
        <!-- Identifier value for the header. -->
        < attr name= "id" format = "integer"/>
        < attr name= "icon" format = "integer" />
        <!-- The fragment that is displayed when the user selects this item. -->
    </declare-styleable >
    < declare-styleable name= "Preference" >
        < attr name= "icon" format = "integer" />
        <!-- The key to store the Preference value. -->
        < attr name= "key" format = "string" />
    </declare-styleable >
</ resources >

icon独立定义，就可以被多次引用了。

<? xml version = "1.0" encoding = "utf-8" ?>
< resources >
     < attr name = "icon" format = "integer" />

     < declare-styleable name= "PreferenceHeader" >
        <!-- Identifier value for the header. -->
        < attr name= "id" format = "integer"/>
        < attr name= "icon" />
    </declare-styleable >

    < declare-styleable name= "Preference" >
        < attr name= "icon"  />
        <!-- The key to store the Preference value. -->
        < attr name= "key" format = "string" />
    </declare-styleable >

</ resources >

参考自：http://www.jcodecraeer.com/a/anzhuokaifa/androidkaifa/2014/0929/1718.html