XmlTextWriter.WriteStartAttribute(String, String, String) Método
Definição
Importante
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Escreve o início de um atributo.
public:
override void WriteStartAttribute(System::String ^ prefix, System::String ^ localName, System::String ^ ns);
public override void WriteStartAttribute(string? prefix, string localName, string? ns);
public override void WriteStartAttribute(string prefix, string localName, string ns);
override this.WriteStartAttribute : string * string * string -> unit
Public Overrides Sub WriteStartAttribute (prefix As String, localName As String, ns As String)
Parâmetros
- prefix
- String
Namespace prefixo do atributo.
- localName
- String
LocalName do atributo.
- ns
- String
NamespaceURI do atributo.
Exceções
localName é null ou String.Empty.
Exemplos
O exemplo seguinte escreve um livro.
using System;
using System.IO;
using System.Xml;
public class Sample
{
private const string filename = "sampledata.xml";
public static void Main()
{
XmlTextWriter writer = new XmlTextWriter (filename, null);
//Use indenting for readability.
writer.Formatting = Formatting.Indented;
writer.WriteComment("sample XML fragment");
//Write an element (this one is the root).
writer.WriteStartElement("bookstore");
//Write the namespace declaration.
writer.WriteAttributeString("xmlns", "bk", null, "urn:samples");
writer.WriteStartElement("book");
//Lookup the prefix and then write the ISBN attribute.
string prefix = writer.LookupPrefix("urn:samples");
writer.WriteStartAttribute(prefix, "ISBN", "urn:samples");
writer.WriteString("1-861003-78");
writer.WriteEndAttribute();
//Write the title.
writer.WriteStartElement("title");
writer.WriteString("The Handmaid's Tale");
writer.WriteEndElement();
//Write the price.
writer.WriteElementString("price", "19.95");
//Write the style element.
writer.WriteStartElement(prefix, "style", "urn:samples");
writer.WriteString("hardcover");
writer.WriteEndElement();
//Write the end tag for the book element.
writer.WriteEndElement();
//Write the close tag for the root element.
writer.WriteEndElement();
//Write the XML to file and close the writer.
writer.Flush();
writer.Close();
//Read the file back in and parse to ensure well formed XML.
XmlDocument doc = new XmlDocument();
//Preserve white space for readability.
doc.PreserveWhitespace = true;
//Load the file
doc.Load(filename);
//Write the XML content to the console.
Console.Write(doc.InnerXml);
}
}
Option Strict
Option Explicit
Imports System.IO
Imports System.Xml
Public Class Sample
Private Shared filename As String = "sampledata.xml"
Public Shared Sub Main()
Dim writer As New XmlTextWriter(filename, Nothing)
'Use indenting for readability.
writer.Formatting = Formatting.Indented
writer.WriteComment("sample XML fragment")
'Write an element (this one is the root).
writer.WriteStartElement("bookstore")
'Write the namespace declaration.
writer.WriteAttributeString("xmlns", "bk", Nothing, "urn:samples")
writer.WriteStartElement("book")
'Lookup the prefix and then write the ISBN attribute.
Dim prefix As String = writer.LookupPrefix("urn:samples")
writer.WriteStartAttribute(prefix, "ISBN", "urn:samples")
writer.WriteString("1-861003-78")
writer.WriteEndAttribute()
'Write the title.
writer.WriteStartElement("title")
writer.WriteString("The Handmaid's Tale")
writer.WriteEndElement()
'Write the price.
writer.WriteElementString("price", "19.95")
'Write the style element.
writer.WriteStartElement(prefix, "style", "urn:samples")
writer.WriteString("hardcover")
writer.WriteEndElement()
'Write the end tag for the book element.
writer.WriteEndElement()
'Write the close tag for the root element.
writer.WriteEndElement()
'Write the XML to file and close the writer.
writer.Flush()
writer.Close()
'Read the file back in and parse to ensure well formed XML.
Dim doc As New XmlDocument()
'Preserve white space for readability.
doc.PreserveWhitespace = True
'Load the file.
doc.Load(filename)
'Write the XML content to the console.
Console.Write(doc.InnerXml)
End Sub
End Class
Observações
Note
Recomendamos que crie instâncias XmlWriter usando o método XmlWriter.Create e a classe XmlWriterSettings para aproveitar a nova funcionalidade.
Esta é uma versão mais avançada que WriteAttributeString permite escrever um valor de atributo usando múltiplos métodos de escrita, como WriteString.