XmlSchemaKeyref Class

Definition

Namespace:

System.Xml.Schema

Assemblies:

netstandard.dll, System.Xml.ReaderWriter.dll

Source:

XmlSchemaIdEntityConstraint.cs

This class represents the keyref element from XMLSchema as specified by the World Wide Web Consortium (W3C).

C#

public class XmlSchemaKeyref : System.Xml.Schema.XmlSchemaIdentityConstraint

Inheritance

Object

XmlSchemaObject

XmlSchemaAnnotated

XmlSchemaIdentityConstraint

XmlSchemaKeyref

Examples

The following example creates a key element.

C#

using System;
using System.Collections;
using System.IO;
using System.Xml;
using System.Xml.Xsl;
using System.Xml.Schema;

public class XmlSchemaObjectGenerator {

    private static void ValidationCallback(object sender, ValidationEventArgs args ){

    if(args.Severity == XmlSeverityType.Warning)
        Console.Write("WARNING: ");
    else if(args.Severity == XmlSeverityType.Error)
        Console.Write("ERROR: ");

    Console.WriteLine(args.Message);
    }

    public static void Main() {

      XmlTextReader tr = new XmlTextReader("empty.xsd");
        XmlSchema schema = XmlSchema.Read(tr, new ValidationEventHandler(ValidationCallback));

            schema.ElementFormDefault = XmlSchemaForm.Qualified;

            schema.TargetNamespace = "http://www.example.com/Report";

            {

        XmlSchemaElement element = new XmlSchemaElement();
        element.Name = "purchaseReport";

        XmlSchemaComplexType element_complexType = new XmlSchemaComplexType();

        XmlSchemaSequence element_complexType_sequence = new XmlSchemaSequence();

            {

        XmlSchemaElement element_complexType_sequence_element = new XmlSchemaElement();
        element_complexType_sequence_element.Name = "region";
        element_complexType_sequence_element.SchemaTypeName =
                new XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema")
            ;

            {

        XmlSchemaKeyref element_complexType_sequence_element_keyref = new XmlSchemaKeyref();
        element_complexType_sequence_element_keyref.Name = "dummy2";
        element_complexType_sequence_element_keyref.Selector = new XmlSchemaXPath();
            element_complexType_sequence_element_keyref.Selector.XPath = "r:zip/r:part";

            {
                XmlSchemaXPath field = new XmlSchemaXPath();
                
                field.XPath = "@number";
                element_complexType_sequence_element_keyref.Fields.Add(field);
            }
        element_complexType_sequence_element_keyref.Refer =
                new XmlQualifiedName("pNumKey", "http://www.example.com/Report")
            ;
        element_complexType_sequence_element.Constraints.Add(element_complexType_sequence_element_keyref);
            }
        element_complexType_sequence.Items.Add(element_complexType_sequence_element);
            }
        element_complexType.Particle = element_complexType_sequence;

            {

        XmlSchemaAttribute element_complexType_attribute = new XmlSchemaAttribute();
        element_complexType_attribute.Name = "periodEnding";
        element_complexType_attribute.SchemaTypeName =
                new XmlQualifiedName("date", "http://www.w3.org/2001/XMLSchema")
            ;
        element_complexType.Attributes.Add(element_complexType_attribute);
            }
        element.SchemaType = element_complexType;

            {

        XmlSchemaKey element_key = new XmlSchemaKey();
        element_key.Name = "pNumKey";
        element_key.Selector = new XmlSchemaXPath();
            element_key.Selector.XPath = "r:parts/r:part";

            {
                XmlSchemaXPath field = new XmlSchemaXPath();
                
                field.XPath = "@number";
                element_key.Fields.Add(field);
            }
        element.Constraints.Add(element_key);
            }

                schema.Items.Add(element);
            }

        schema.Write(Console.Out);
    }/* Main() */
}
//XmlSchemaObjectGenerator

The following XML file is generated for the preceding code example.

XML

<?xml version="1.0" encoding="IBM437"?>
<xs:schema xmlns:r="http://www.example.com/Report" elementFormDefault="qualified" targetNamespace="http://www.example.com/Report" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="purchaseReport">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="region" type="xs:string">
          <xs:keyref name="dummy2" refer="r:pNumKey">
            <xs:selector xpath="r:zip/r:part" />
            <xs:field xpath="@number" />
          </xs:keyref>
        </xs:element>
      </xs:sequence>
      <xs:attribute name="periodEnding" type="xs:date" />
    </xs:complexType>
    <xs:key name="pNumKey">
      <xs:selector xpath="r:parts/r:part" />
      <xs:field xpath="@number" />
    </xs:key>
  </xs:element>
</xs:schema>

Remarks

Specifies that an attribute or element value (or set of values) has a correspondence with those of the specified key or unique element. The constraint name must be unique within a schema.

Constructors

XmlSchemaKeyref()

Initializes a new instance of the XmlSchemaKeyref class.

Properties

Annotation	Gets or sets the annotation property. (Inherited from XmlSchemaAnnotated)
Fields	Gets the collection of fields that apply as children for the XML Path Language (XPath) expression selector. (Inherited from XmlSchemaIdentityConstraint)
Id	Gets or sets the string id. (Inherited from XmlSchemaAnnotated)
LineNumber	Gets or sets the line number in the file to which the schema element refers. (Inherited from XmlSchemaObject)
LinePosition	Gets or sets the line position in the file to which the schema element refers. (Inherited from XmlSchemaObject)
Name	Gets or sets the name of the identity constraint. (Inherited from XmlSchemaIdentityConstraint)
Namespaces	Gets or sets the XmlSerializerNamespaces to use with this schema object. (Inherited from XmlSchemaObject)
Parent	Gets or sets the parent of this XmlSchemaObject. (Inherited from XmlSchemaObject)
QualifiedName	Gets the qualified name of the identity constraint, which holds the post-compilation value of the QualifiedName property. (Inherited from XmlSchemaIdentityConstraint)
Refer	Gets or sets the name of the key that this constraint refers to in another simple or complex type.
Selector	Gets or sets the XPath expression selector element. (Inherited from XmlSchemaIdentityConstraint)
SourceUri	Gets or sets the source location for the file that loaded the schema. (Inherited from XmlSchemaObject)
UnhandledAttributes	Gets or sets the qualified attributes that do not belong to the current schema's target namespace. (Inherited from XmlSchemaAnnotated)

Methods

Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

Applies to