xml - 如何使 XMLDOMDocument 包含 XML 声明？

Question

当 XMLDOMDocument 保存自身时，我怎样才能让它包含 XML 声明，例如:

• <?xml version="1.0" encoding="UTF-8" ?>
• <?xml version="1.0" encoding="UTF-16" ?>
• <?xml version="1.0" encoding="UCS-2" ?>
• <?xml version="1.0" encoding="UCS-4" ?>
• <?xml version="1.0" encoding="ISO-10646-UCS-2" ?>
• <?xml version="1.0" encoding="UNICODE-1-1-UTF-8" ?>
• <?xml version="1.0" encoding="UNICODE-2-0-UTF-16" ?>
• <?xml version="1.0" encoding="UNICODE-2-0-UTF-8" ?>
• <?xml version="1.0" encoding="US-ASCII" ?>
• <?xml version="1.0" encoding="ISO-8859-1" ?>
• <?xml version="1.0" encoding="WINDOWS-1250" ?>

正在内存中创建 XMLDOMDomcument 对象(即未从某些外部源加载 xml):

{
   IXMLDOMDocument2 doc = new DOMDocument60();

   //add nodes to the doc
   ...

   doc.Save(saveTarget);
}

如果没有 xml 声明，您只会得到主体 xml，例如:

<Customer>
   ...
</Customer>

而不是完整的 XML 文档:

<?xml version="1.0" encoding="US-ASCII" ?>
<Customer>
   ...
</Customer>

问题2

我如何控制 encoding the XMLDOMDocument将在保存到流时使用？

Answer 1

您需要使用 MXXMLWriter60，而不是直接保存它。抱歉，我没有 C# 示例，但这是 VB.Net 的等效示例。参见 IMXWriter了解详情。

' Create and load a DOMDocument object.

Dim xmlDoc As New DOMDocument60
xmlDoc.loadXML("<doc><one>test1</one><two>test2</two></doc>")

' Set properties on the XML writer - including BOM, XML declaration and encoding

Dim wrt As New MXXMLWriter60
wrt.byteOrderMark = True
wrt.omitXMLDeclaration = False
wrt.encoding = "US-ASCII"
wrt.indent = True

' Set the XML writer to the SAX content handler.

Dim rdr As New SAXXMLReader60
Set rdr.contentHandler = wrt
Set rdr.dtdHandler = wrt
Set rdr.errorHandler = wrt
rdr.putProperty "http://xml.org/sax/properties/lexical-handler", wrt
rdr.putProperty "http://xml.org/sax/properties/declaration-handler", wrt

' Now pass the DOM through the SAX handler, and it will call the writer

rdr.parse xmlDoc

' Let the writer do its thing

Dim iFileNo As Integer
iFileNo = FreeFile
Open App.Path + "\saved.xml" For Output As #iFileNo
Print #iFileNo, wrt.output
Close #iFileNo