.NET & XML

Creating a Schema Programmatically

As you already know, xs:schema is the root element of an XSD document. XmlSchema is the type that represents the xs:schema element.

XmlSchema is a subclass of XmlSchemaObject, whose other subclasses are XmlSchemaAnnotated, XmlSchemaAnnotation, XmlSchemaAppInfo, XmlSchemaDocumentation, and XmlSchemaExternal. Each of these subclasses represents a specific type of XML Schema element, and some of them have their own subclasses. The .NET XmlSchema type hierarchy is shown in Figure 8-1.

Figure 8-1. XmlSchema type hierarchy

Table 8-4 shows each XML Schema element name with its corresponding .NET type. In some cases, more than one .NET class is used for the same XML Schema element; typically, this is the case when the same element has different behavior in different contexts. There are many more types in the System.Xml.Schema assembly that do not correspond directly to an XML Schema element, and they are listed in the assembly reference in Chapter 17.

Table 8-4. XML Schema element names and .NET types

XML Schema element name	.NET type
xs:all	XmlSchemaAll
xs:annotation	XmlSchemaAnnotation
xs:any	XmlSchemaAny
xs:anyAttribute	XmlSchemaAnyAttribute
xs:appinfo	XmlSchemaAppInfo
xs:attribute	XmlSchemaAttribute
xs:attributeGroup	XmlSchemaAttributeGroup XmlSchemaAttributeGroupRef
xs:choice	XmlSchemaChoice ...