<?xml version="1.0"?>
<ren xmlns="http://your_namespace"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.heihei.com/abce/xsd.xsd"
>
<name>xuexue</name>
<age>21</age>
</ren>
----------------------------------------
xsd.xsd文件如下：
<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://www.heihei.com/abce"
xmlns="http://http://www.heihei.com/hei">
<xsd:element name="re">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="name" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:schema>

请问 xml 是怎么引用xsd的？
上面的xsd.xml:的文件中<ren xmlns="http://your_namespace"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.heihei.com/abce/xsd.xsd"
>是什么意思？其中的‘xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
’是固定的吗？而“xsi:schemaLocation="http://www.heihei.com/abce/xsd.xsd"”又是什么意思？？

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   your xsi:element/attribute will automatically look for this namespace

xsi:schemaLocation="http://www.heihei.com/abce/xsd.xsd"  it's your schema xsd location, normally the xml file will look for the xsd.xsd fine in the current directory first.