XmlSchemaUnique Class
Represents the unique element from XML Schema as specified by the . This class can be used to identify a unique constraint among a set of elements.
System.Xml.Schema.XmlSchemaObject
System.Xml.Schema.XmlSchemaAnnotated
System.Xml.Schema.XmlSchemaIdentityConstraint
System.Xml.Schema.XmlSchemaUnique
Assembly: System.Xml (in System.Xml.dll)
The XmlSchemaUnique type exposes the following members.
| Name | Description | |
|---|---|---|
![]() ![]() | 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.) |
![]() ![]() | 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.) |
| Name | Description | |
|---|---|---|
![]() ![]() | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
![]() ![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() ![]() | GetHashCode | Serves as a hash function for a particular type. (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.) |
The following example shows the use of the XmlSchemaUnique class.
Imports System Imports System.Xml Imports System.Xml.Schema Class XMLSchemaExamples Public Shared Sub Main() Dim schema As New XmlSchema() ' <xs:complexType name="customerOrderType"> Dim customerOrderType As New XmlSchemaComplexType() customerOrderType.Name = "customerOrderType" ' <xs:sequence> Dim sequence1 As New XmlSchemaSequence() ' <xs:element name="item" minOccurs="0" maxOccurs="unbounded"> Dim item As New XmlSchemaElement() item.MinOccurs = 0 item.MaxOccursString = "unbounded" item.Name = "item" ' <xs:complexType> Dim ct1 As New XmlSchemaComplexType() ' <xs:attribute name="itemID" type="xs:string"/> Dim itemID As New XmlSchemaAttribute() itemID.Name = "itemID" itemID.SchemaTypeName = New XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema") ' </xs:complexType> ct1.Attributes.Add(itemID) ' </xs:element> item.SchemaType = ct1 ' </xs:sequence> sequence1.Items.Add(item) customerOrderType.Particle = sequence1 ' <xs:attribute name="CustomerID" type="xs:string"/> Dim CustomerID As New XmlSchemaAttribute() CustomerID.Name = "CustomerID" CustomerID.SchemaTypeName = New XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema") customerOrderType.Attributes.Add(CustomerID) ' </xs:complexType> schema.Items.Add(customerOrderType) ' <xs:element name="ordersByCustomer"> Dim ordersByCustomer As New XmlSchemaElement() ordersByCustomer.Name = "ordersByCustomer" ' <xs:complexType> Dim ct2 As New XmlSchemaComplexType() ' <xs:sequence> Dim sequence2 As New XmlSchemaSequence() ' <xs:element name="customerOrders" type="customerOrderType" minOccurs="0" maxOccurs="unbounded" /> Dim customerOrders As New XmlSchemaElement() customerOrders.MinOccurs = 0 customerOrders.MaxOccursString = "unbounded" customerOrders.Name = "customerOrders" customerOrders.SchemaTypeName = New XmlQualifiedName("customerOrderType", "") ' </xs:sequence> sequence2.Items.Add(customerOrders) ' </xs:complexType> ct2.Particle = sequence2 ordersByCustomer.SchemaType = ct2 ' <xs:unique name="oneCustomerOrdersforEachCustomerID"> Dim element_unique As New XmlSchemaUnique() element_unique.Name = "oneCustomerOrdersforEachCustomerID" ' <xs:selector xpath="customerOrders"/> element_unique.Selector = New XmlSchemaXPath() element_unique.Selector.XPath = "customerOrders" ' <xs:field xpath="@customerID"/> Dim field As New XmlSchemaXPath() field.XPath = "@customerID" ' </xs:unique> element_unique.Fields.Add(field) ordersByCustomer.Constraints.Add(element_unique) ' </xs:element> schema.Items.Add(ordersByCustomer) Dim schemaSet As New XmlSchemaSet() AddHandler schemaSet.ValidationEventHandler, AddressOf ValidationCallbackOne schemaSet.Add(schema) schemaSet.Compile() Dim compiledSchema As XmlSchema = Nothing For Each schema1 As XmlSchema In schemaSet.Schemas() compiledSchema = schema1 Next Dim nsmgr As New XmlNamespaceManager(New NameTable()) nsmgr.AddNamespace("xs", "http://www.w3.org/2001/XMLSchema") compiledSchema.Write(Console.Out, nsmgr) End Sub Public Shared Sub ValidationCallbackOne(ByVal sender As Object, ByVal args As ValidationEventArgs) Console.WriteLine(args.Message) End Sub End Class
The following XML file is generated for this code example.
<?xml version="1.0" encoding="IBM437"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> <xs:complexType name="customerOrderType"> <xs:sequence> <xs:element name="item" minOccurs="0" maxOccurs="unbounded"> <xs:complexType> <xs:attribute name="itemID" type="xs:string"/> </xs:complexType> </xs:element> </xs:sequence> <xs:attribute name="CustomerID" type="xs:string"/> </xs:complexType> <xs:element name="ordersByCustomer"> <xs:complexType> <xs:sequence> <xs:element name="customerOrders" type="customerOrderType" minOccurs="0" maxOccurs="unbounded" /> </xs:sequence> </xs:complexType> <xs:unique name="oneCustomerOrdersforEachCustomerID"> <xs:selector xpath="customerOrders"/> <xs:field xpath="@customerID"/> </xs:unique> </xs:element> </xs:schema>
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.



