Xml 如何使属性在xsd中唯一？

XML:

XSD:

---

我希望'screen'标签的'screenNumber'属性是唯一的。哪里出错了？

可能是由于名称空间的原因，请尝试在选择器前面加前缀：

...
<xsd:element name="configuration" 
  type="configuration.configuration.type">
  <xsd:unique name="uConfiguration">
    <xsd:selector xpath="screen" /> 
    <xsd:field xpath="@screenNumber" /> 
  </xsd:unique>
</xsd:element>

...
<xsd:element name="configuration" 
  type="configuration.configuration.type">
  <xsd:unique name="uConfiguration">
    <xsd:selector xpath="screen" /> 
    <xsd:field xpath="@screenNumber" /> 
  </xsd:unique>
</xsd:element>

    <xsd:unique name="uConfiguration">
        <xsd:selector xpath="p:screen"/>
        <xsd:field xpath="@screenNumber"/>
    </xsd:unique>