我知道,任何“全球界定的内容都可以作为根本要素使用,XML Schema没有确定哪些根本要素的概念。

You can however work around this by designing your XML Schema well, so that there is only one globally defined element - then only this element is valid as root element.

An example of this can be found at W3Schools (heading Using Named Types) This example only has one globally defined element, and thus only one possible root element.

并非每个人都同意,但XML Schema能够具体指明一个根本要素的事实是设计的。 据认为,如果<代码><invoice>在单证中是唯一一件事时有效,则该编码在其他文件中同样有效。 想法是,内容应当可以重新使用,而不应允许你阻止使用有效内容作为更大内容的一部分的人。

(The fact that ID and IDREF are scoped to a document rather goes against this policy; but then the language was designed by a rather large committee.)

是的,你是正确的。 the

<?xml version="1.0" encoding="ISO-8859-1" ?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<!-- definition of attributes -->
<xs:attribute name="orderid" type="xs:string"/>

<!-- definition of complex elements -->
<xs:complexType name="shiptoType">
  <xs:sequence>
    <xs:element name="name" type="xs:string" />
    <xs:element name="address" type="xs:string" />
    <xs:element name="city" type="xs:string" />
    <xs:element name="country" type="xs:string" />
  </xs:sequence>
</xs:complexType>

<xs:complexType name="itemType">
  <xs:sequence>
    <xs:element name="title" type="xs:string" />
    <xs:element name="note" minOccurs="0" type="xs:string" />
    <xs:element name="quantity" type="xs:string" />
    <xs:element name="price" type="xs:string" />
  </xs:sequence>
</xs:complexType>

<xs:element name="shiporder">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="orderperson" type="xs:string" />
      <xs:element name="shipto" type="shiptoType"/>
      <xs:element name="item" maxOccurs="unbounded" type="itemType"/>
    </xs:sequence>
    <xs:attribute ref="orderid" use="required"/>
  </xs:complexType>
</xs:element>

</xs:schema>

如你所知,现在只有一个<条码>x:element,只有一条能够成为有效根本要素:

How does this code indicate that is the root element?

John, That schema just defined all the elements and any of those can be chosen as a root element. If you try generating a sample xml from any tool like Altova XML Spy or its kind, you will get to choose an element to be the root element.

因此,任何这些因素都可能是根本的。

To prevent ambiguity, use one globally defined element.

全球许多因素的不利之处在于,它们都可以作为文件的根本内容。 这样,在界定新的类型时,你就可以利用这一要素,确保儿童部分的名称空间与父母类型相匹配。

I have changed from thinking there should only be one global element to that all complex types should have a global element.

根据你提供的例子,可以找到唯一的根本内容。

You can get a list of global elements, then get a list a nested elements that referenced in complexType under the node xs:sequence, thus the root element is the one in global elements list but not in nested elements list.

我通过在互联网上使用XmlSchemaSet的班子这样做。 这里是法典:

var localSchema = schemaSet.Schemas().OfType<XmlSchema>().Where(x => !x.SourceUri.StartsWith("http")).ToList();

var globalComplexTypes = localSchema
.SelectMany(x => x.Elements.Values.OfType<XmlSchemaElement>())
.Where(x => x.ElementSchemaType is XmlSchemaComplexType)
.ToList();

var nestedTypes = globalComplexTypes.Select(x => x.ElementSchemaType)
.OfType<XmlSchemaComplexType>()
.Select(x => x.ContentTypeParticle)
.OfType<XmlSchemaGroupBase>()
.SelectMany(x => x.GetNestedTypes())
.ToList();

var rootElement= globalComplexTypes.Single(x => !nestedTypes.Select(y => y.ElementSchemaType.QualifiedName).Contains(x.SchemaTypeName));

The extension method GetNestedTypes:

static IEnumerable<XmlSchemaElement> GetNestedTypes(this XmlSchemaGroupBase xmlSchemaGroupBase)
{
    if (xmlSchemaGroupBase != null)
    {
        foreach (var xmlSchemaObject in xmlSchemaGroupBase.Items)
        {
            var element = xmlSchemaObject as XmlSchemaElement;
            if (element != null)
                yield return element;
            else
            {
                var group = xmlSchemaObject as XmlSchemaGroupBase;
                if (group != null)
                    foreach (var item in group.GetNestedTypes())
                        yield return item;
            }
        }
    }
}

But there still has problems for the general xsd when using this approach. For example, in DotNetConfig.xsd that Visual studio use for configuration file, the root element is define as below:

  <xs:element name="configuration">
    <xs:complexType>
      <xs:choice minOccurs="0" maxOccurs="unbounded">
        <xs:any namespace="##any" processContents="lax" />
      </xs:choice>
      <xs:anyAttribute namespace="http://schemas.microsoft.com/XML-Document-Transform" processContents="strict"/>
    </xs:complexType>
  </xs:element>

我没有找到一个完整的解决办法来处理各种chem。 将继续这样做。