XmlWriter.WriteQualifiedName Method
When overridden in a derived class, writes out the namespace-qualified name. This method looks up the prefix that is in scope for the given namespace.
Namespace: System.Xml
Assembly: System.Xml (in System.Xml.dll)
Parameters
- localName
- Type: System.String
The local name to write.
- ns
- Type: System.String
The namespace URI for the name.
| Exception | Condition |
|---|---|
| ArgumentException | localName is either null or String.Empty. localName is not a valid name. |
| InvalidOperationException | An XmlWriter method was called before a previous asynchronous operation finished. In this case, InvalidOperationException is thrown with the message “An asynchronous operation is already in progress.” |
If ns maps to the current default namespace, no prefix is generated.
When writing attribute values, this method generates a prefix if ns is not found. When writing element content, it throws an exception if ns is not found.
 Note |
|---|
If a class derived from the XmlWriter does not override this method localName is not checked to be a valid W3C XML name. In such case, before calling this method, the validity of the string can be checked by IsName method. |
For the asynchronous version of this method, see WriteQualifiedNameAsync.
The example writes the following element:
<root xmlns:x="urn:abc"> <item href="#x:test"/> </root>
XmlWriterSettings settings = new XmlWriterSettings(); settings.Indent = true; settings.OmitXmlDeclaration = true; using (XmlWriter writer = XmlWriter.Create(Console.Out, settings)) { writer.WriteStartElement("root"); writer.WriteAttributeString("xmlns", "x", null, "urn:abc"); writer.WriteStartElement("item"); writer.WriteStartAttribute("href", null); writer.WriteString("#"); writer.WriteQualifiedName("test", "urn:abc"); writer.WriteEndAttribute(); writer.WriteEndElement(); writer.WriteEndElement(); }
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
