通过

XmlTextWriter.WriteStartDocument 方法

  • 参考

定义

命名空间:
System.Xml
程序集:
System.Xml.ReaderWriter.dll
程序集:
System.Xml.dll
程序集:
netstandard.dll

写入版本为“1.0”的 XML 声明。

重载

WriteStartDocument()

写入版本为“1.0”的 XML 声明。
WriteStartDocument(Boolean)

写入版本为“1.0”的 XML 声明和独立的属性。

注解

备注

从 .NET Framework 2.0 开始，我们建议使用XmlWriter.Create方法和XmlWriterSettings类创建XmlWriter实例，以利用新功能。

WriteStartDocument()

写入版本为“1.0”的 XML 声明。

public:
 override void WriteStartDocument();
public override void WriteStartDocument ();
override this.WriteStartDocument : unit -> unit
Public Overrides Sub WriteStartDocument ()

例外

InvalidOperationException

这不是在构造函数后调用的第一个写方法。

示例

以下示例编写一个表示书籍的 XML 文件。

#using <System.Xml.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml;
int main()
{
   XmlTextWriter^ writer = nullptr;
   String^ filename = "sampledata.xml";
   writer = gcnew XmlTextWriter( filename, nullptr );
   
   //Use indenting for readability.
   writer->Formatting = Formatting::Indented;
   
   //Write the XML delcaration. 
   writer->WriteStartDocument();
   
   //Write the ProcessingInstruction node.
   String^ PItext = "type='text/xsl' href='book.xsl'";
   writer->WriteProcessingInstruction( "xml-stylesheet", PItext );
   
   //Write the DocumentType node.
   writer->WriteDocType( "book", nullptr, nullptr, "<!ENTITY h 'hardcover'>" );
   
   //Write a Comment node.
   writer->WriteComment( "sample XML" );
   
   //Write a root element.
   writer->WriteStartElement( "book" );
   
   //Write the genre attribute.
   writer->WriteAttributeString( "genre", "novel" );
   
   //Write the ISBN attribute.
   writer->WriteAttributeString( "ISBN", "1-8630-014" );
   
   //Write the title.
   writer->WriteElementString( "title", "The Handmaid's Tale" );
   
   //Write the style element.
   writer->WriteStartElement( "style" );
   writer->WriteEntityRef( "h" );
   writer->WriteEndElement();
   
   //Write the price.
   writer->WriteElementString( "price", "19.95" );
   
   //Write CDATA.
   writer->WriteCData( "Prices 15% off!!" );
   
   //Write the close tag for the root element.
   writer->WriteEndElement();
   writer->WriteEndDocument();
   
   //Write the XML to file and close the writer.
   writer->Flush();
   writer->Close();
   
   //Load the file into an XmlDocument to ensure well formed XML.
   XmlDocument^ doc = gcnew XmlDocument;
   
   //Preserve white space for readability.
   doc->PreserveWhitespace = true;
   
   //Load the file.
   doc->Load( filename );
   
   //Display the XML content to the console.
   Console::Write( doc->InnerXml );
}

using System;
using System.IO;
using System.Xml;

public class Sample
{
  private const string filename = "sampledata.xml";

  public static void Main()
  {
     XmlTextWriter writer = null;

     writer = new XmlTextWriter (filename, null);
     //Use indenting for readability.
     writer.Formatting = Formatting.Indented;

     //Write the XML delcaration.
     writer.WriteStartDocument();

     //Write the ProcessingInstruction node.
     String PItext="type='text/xsl' href='book.xsl'";
     writer.WriteProcessingInstruction("xml-stylesheet", PItext);

     //Write the DocumentType node.
     writer.WriteDocType("book", null , null, "<!ENTITY h 'hardcover'>");

     //Write a Comment node.
     writer.WriteComment("sample XML");

     //Write a root element.
     writer.WriteStartElement("book");

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

     //Write the ISBN attribute.
     writer.WriteAttributeString("ISBN", "1-8630-014");

     //Write the title.
     writer.WriteElementString("title", "The Handmaid's Tale");

     //Write the style element.
     writer.WriteStartElement("style");
     writer.WriteEntityRef("h");
     writer.WriteEndElement();

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

     //Write CDATA.
     writer.WriteCData("Prices 15% off!!");

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

     writer.WriteEndDocument();

     //Write the XML to file and close the writer.
     writer.Flush();
     writer.Close();

     //Load the file into an XmlDocument to ensure well formed XML.
     XmlDocument doc = new XmlDocument();
     //Preserve white space for readability.
     doc.PreserveWhitespace = true;
     //Load the file.
     doc.Load(filename);

     //Display the XML content to the console.
     Console.Write(doc.InnerXml);
  }
}

Option Explicit
Option Strict

Imports System.IO
Imports System.Xml

Public Class Sample
    Private Shared filename As String = "sampledata.xml"
    Public Shared Sub Main()
        Dim writer As XmlTextWriter = Nothing
        
        writer = New XmlTextWriter(filename, Nothing)
        'Use indenting for readability.
        writer.Formatting = Formatting.Indented
        
        'Write the XML delcaration. 
        writer.WriteStartDocument()
        
        'Write the ProcessingInstruction node.
        Dim PItext As String = "type='text/xsl' href='book.xsl'"
        writer.WriteProcessingInstruction("xml-stylesheet", PItext)
        
        'Write the DocumentType node.
        writer.WriteDocType("book", Nothing, Nothing, "<!ENTITY h 'hardcover'>")
        
        'Write a Comment node.
        writer.WriteComment("sample XML")
        
        'Write a root element.
        writer.WriteStartElement("book")
        
        'Write the genre attribute.
        writer.WriteAttributeString("genre", "novel")
        
        'Write the ISBN attribute.
        writer.WriteAttributeString("ISBN", "1-8630-014")
        
        'Write the title.
        writer.WriteElementString("title", "The Handmaid's Tale")
        
        'Write the style element.
        writer.WriteStartElement("style")
        writer.WriteEntityRef("h")
        writer.WriteEndElement()
        
        'Write the price.
        writer.WriteElementString("price", "19.95")
        
        'Write CDATA.
        writer.WriteCData("Prices 15% off!!")
        
        'Write the close tag for the root element.
        writer.WriteEndElement()
        
        writer.WriteEndDocument()
        
        'Write the XML to file and close the writer.
        writer.Flush()
        writer.Close()
        
        'Load the file into an XmlDocument to ensure well formed XML.
        Dim doc As New XmlDocument()
        'Preserve white space for readability.
        doc.PreserveWhitespace = True
        'Load the file.
        doc.Load(filename)
        
        'Display the XML content to the console.
        Console.Write(doc.InnerXml)
    End Sub
End Class

注解

备注

从 .NET Framework 2.0 开始，我们建议使用XmlWriter.Create方法和XmlWriterSettings类创建XmlWriter实例，以利用新功能。

文档的编码级别由编写器实现方式决定。 例如，如果在构造函数中XmlTextWriter指定对象Encoding，则确定编码特性的值。 此方法不创建独立属性。

调用编写器时 WriteStartDocument ，验证正在编写的内容是否是格式正确的 XML 文档。 例如，它会检查 XML 声明是否是第一个节点，其中一个和只有一个根级元素存在，依此而行。 如果未调用此方法，编写器假定正在编写 XML 片段，并且不应用根级别规则。

如果 WriteStartDocument 已调用，然后 WriteProcessingInstruction 该方法用于创建另一个 XML 声明，则会引发异常。

适用于

WriteStartDocument(Boolean)

写入版本为“1.0”的 XML 声明和独立的属性。

public:
 override void WriteStartDocument(bool standalone);
public override void WriteStartDocument (bool standalone);
override this.WriteStartDocument : bool -> unit
Public Overrides Sub WriteStartDocument (standalone As Boolean)

参数

standalone
Boolean

如果为 true，则它将写入"standalone=yes"；如果为 false，则它将写入"standalone=no"。

例外

InvalidOperationException

这不是在构造函数后调用的第一个写方法。

注解

备注

从 .NET Framework 2.0 开始，我们建议使用XmlWriter.Create方法和XmlWriterSettings类创建XmlWriter实例，以利用新功能。

文档的编码级别由编写器实现方式决定。 例如，如果在构造函数中XmlTextWriter指定对象Encoding，则确定编码特性的值。

调用编写器时 WriteStartDocument ，验证正在编写的内容是否是格式正确的 XML 文档。 例如，它会检查 XML 声明是否是第一个节点，其中一个和只有一个根级元素存在，依此而行。 如果未调用此方法，编写器假定正在编写 XML 片段，并且不应用根级别规则。

如果 WriteStartDocument 已调用，然后 WriteProcessingInstruction 该方法用于创建另一个 XML 声明，则会引发异常。

适用于