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XmlWriter.LookupPrefix Method

When overridden in a derived class, returns the closest prefix defined in the current namespace scope for the namespace URI.

Namespace:  System.Xml
Assembly:  System.Xml (in System.Xml.dll)

public abstract string LookupPrefix(
	string ns
)

Parameters

ns
Type: System.String
The namespace URI whose prefix you want to find.

Return Value

Type: System.String
The matching prefix or null if no matching namespace URI is found in the current scope.

ExceptionCondition
ArgumentException

ns is either null or String.Empty.



StringBuilder output = new StringBuilder();

XmlWriterSettings settings = new XmlWriterSettings();
settings.Indent = true;
using (XmlWriter writer = XmlWriter.Create(output, settings))
{
    writer.WriteComment("sample XML fragment");

    // Write an element (this one is the root).
    writer.WriteStartElement("book");

    // Write the namespace declaration.
    writer.WriteAttributeString("xmlns", "bk", null, "urn:samples");

    // Write the genre attribute.
    writer.WriteAttributeString("genre", "novel");

    // Write the title.
    writer.WriteStartElement("title");
    writer.WriteString("The Handmaid's Tale");
    writer.WriteEndElement();

    // Write the price.
    writer.WriteElementString("price", "19.95");

    // Lookup the prefix and write the ISBN element.
    string prefix = writer.LookupPrefix("urn:samples");
    writer.WriteStartElement(prefix, "ISBN", "urn:samples");
    writer.WriteString("1-861003-78");
    writer.WriteEndElement();

    // Write the style element (shows a different way to handle prefixes).
    writer.WriteElementString("style", "urn:samples", "hardcover");

    // Write the close tag for the root element.
    writer.WriteEndElement();

    // Write the XML to file.
    writer.Flush();
}

OutputTextBlock.Text = output.ToString();


Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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