xml - s4s-elt-invalid-content.1 : The content is invalid. 元素 'attribute' 无效、放错位置或出现太频繁

Question

我有一个 XSD 的 XML，除了一个错误外，一切都很好:

Ln 25 Col 50 - s4s-elt-invalid-content.1: The content of '#AnonType_tracks' is invalid. Element 'attribute' is invalid, misplaced, or occurs too often.

这是我的 XML 代码:

<items xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:noNamespaceSchemaLocation="items.xsd">
<item>
  <title>Kind of Blue</title>
  <priceus>US: $11.99</priceus>
  <priceuk>UK: £8.39</priceuk>
  <artist>Miles Davis</artist>
  <tracks>
     <track length="9:22">So What</track>
     <track length="5:37">Blue in Green</track>
     <track length="11:33">All Blues</track>
     <track length="9:26">Flamenco Sketches</track>
  </tracks>
</item>
<item>
  <title>Blue Train</title>
  <priceus>US: $8.99</priceus>
  <priceuk>UK: £6.29</priceuk>
  <artist>John Coltrane</artist>
  <tracks>
     <track length="10:39">Blue Train</track>
     <track length="9:06">Moment's Notice</track>
     <track length="7:11">Locomotion</track>
  </tracks>
</item>
</items>

这是我的 XSD:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="title" type="xs:string" />
<xs:element name="priceus" type="xs:string" />
<xs:element name="priceuk" type="xs:string" />
<xs:element name="artist" type="xs:string" />
<xs:attribute name="track" type="xs:string" />

<xs:element name="tracks">
  <xs:complexType>
     <xs:simpleContent>
        <xs:attribute ref="track" use="required" />
     </xs:simpleContent>
  </xs:complexType>
 </xs:element>

<xs:element name="item">
  <xs:complexType>
     <xs:sequence>
        <xs:element ref="title" />
        <xs:element ref="priceus" />
        <xs:element ref="priceuk" />
        <xs:element ref="artist" />
        <xs:element ref="tracks"/>
     </xs:sequence>
  </xs:complexType>
</xs:element>

<xs:element name="items">
  <xs:complexType>
     <xs:sequence>
        <xs:element ref="item" minOccurs="1" maxOccurs="unbounded" />
     </xs:sequence>
  </xs:complexType>
</xs:element>
</xs:schema>

Answer 1

<xs:simpleContent>声明不能包含 <attribute>声明，只有 <restriction>或 <extension> .可以在 <restriction> 中指定属性或 <extension> block 。

参见 https://www.safaribooksonline.com/library/view/xml-schema/0596002521/re49.html