当XMLDOMDocument自行保存时，如何让它包含 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xml未从某些外部源加载）：
{
IXMLDOMDocument2 doc = new DOMDocument60();
//add nodes to the doc
...
doc.Save(saveTarget);
}
如果没有xml声明，则只能获取正文xml，例如：
<Customer>
...
</Customer>
而不是完整的XML文档：
<?xml version="1.0" encoding="US-ASCII" ?>
<Customer>
...
</Customer>
如何控制encoding the XMLDOMDocument在保存到流时使用的内容？
答案 0 :(得分：8)
您需要使用MXXMLWriter60，而不是直接保存它。对不起，我没有C＃示例，但这里是VB.Net等价物。有关详细信息，请参阅IMXWriter。
' 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
答案 1 :(得分：3)
您应该能够通过使用CreateProcessingInstruction方法实现相同的目的。
实施例
' Create and load a DOMDocument object.
Dim xmlDoc As New DOMDocument
Dim xRecords As IXMLDOMElement
' Make the Records the root node and add instructional line to XML file.
Set xRecords = xmlDoc.createElement("HeuristicFiler")
xmlDoc.appendChild xmlDoc.createProcessingInstruction("xml", "version=""1.0"" encoding=""UTF-8"" standalone=""yes""")
xmlDoc.appendChild xRecords
' Add various records
' Save the XML File
xmlDoc.Save strFilePath
答案 2 :(得分：2)
这是c ++中的same thing
bool PPrintDOMDocument (IXMLDOMDocument* pDoc, IStream* pStream)
{
// Create the writer
CComPtr <IMXWriter> pMXWriter;
CHK_FAILED(pMXWriter.CoCreateInstance(__uuidof (MXXMLWriter), NULL, CLSCTX_ALL));
CComPtr <ISAXContentHandler> pISAXContentHandler;
CHK_FAILED (pMXWriter.QueryInterface(&pISAXContentHandler));
CComPtr <ISAXErrorHandler> pISAXErrorHandler;
CHK_FAILED(pMXWriter.QueryInterface (&pISAXErrorHandler));
CComPtr <ISAXDTDHandler> pISAXDTDHandler;
CHK_FAILED (pMXWriter.QueryInterface (&pISAXDTDHandler));
CHK_FAILED (pMXWriter->put_omitXMLDeclaration (VARIANT_FALSE));
CHK_FAILED (pMXWriter->put_standalone (VARIANT_TRUE));
CHK_FAILED (pMXWriter->put_indent (VARIANT_TRUE));
CHK_FAILED (pMXWriter->put_encoding (L"UTF-8"));
CComPtr <ISAXXMLReader> pSAXReader;
CHK_FAILED (pSAXReader.CoCreateInstance (__uuidof (SAXXMLReader), NULL, CLSCTX_ALL));
CHK_FAILED (pSAXReader ->putContentHandler (pISAXContentHandler));
CHK_FAILED (pSAXReader ->putDTDHandler (pISAXDTDHandler));
CHK_FAILED (pSAXReader ->putErrorHandler (pISAXErrorHandler));
CHK_FAILED (pSAXReader ->putProperty (
L"http://xml.org/sax/properties/lexical-handler", CComVariant (pMXWriter)));
CHK_FAILED (pSAXReader ->putProperty (
L"http://xml.org/sax/properties/declaration-handler", CComVariant (pMXWriter)));
if (! SUCCEEDED (pMXWriter ->put_output (CComVariant (pStream)))) return false;
if (! SUCCEEDED (pSAXReader->parse(CComVariant (pDoc)))) return false;
pMXWriter->flush();
}
...你需要一个合适的IStream ...
//implement filestream that derives from IStream
class FileStream : public IStream
{
FileStream(HANDLE hFile)
{
_refcount = 1;
_hFile = hFile;
}
~FileStream()
{
if (_hFile != INVALID_HANDLE_VALUE)
{
::CloseHandle(_hFile);
}
}
public:
HRESULT static OpenFile(LPCWSTR pName, IStream ** ppStream, bool fWrite)
{
HANDLE hFile = ::CreateFileW(pName,
fWrite ? GENERIC_WRITE : GENERIC_READ, FILE_SHARE_READ,
NULL,
fWrite ? CREATE_ALWAYS : OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);
if (hFile == INVALID_HANDLE_VALUE)
return HRESULT_FROM_WIN32(GetLastError());
*ppStream = new FileStream(hFile);
if(*ppStream == NULL)
CloseHandle(hFile);
return S_OK;
}
virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, void ** ppvObject)
{
if (iid == __uuidof(IUnknown)
|| iid == __uuidof(IStream)
|| iid == __uuidof(ISequentialStream))
{
*ppvObject = static_cast<IStream*>(this);
AddRef();
return S_OK;
} else
return E_NOINTERFACE;
}
virtual ULONG STDMETHODCALLTYPE AddRef(void)
{
return (ULONG)InterlockedIncrement(&_refcount);
}
virtual ULONG STDMETHODCALLTYPE Release(void)
{
ULONG res = (ULONG) InterlockedDecrement(&_refcount);
if (res == 0)
delete this;
return res;
}
// ISequentialStream Interface
public:
virtual HRESULT STDMETHODCALLTYPE Read(void* pv, ULONG cb, ULONG* pcbRead)
{
BOOL rc = ReadFile(_hFile, pv, cb, pcbRead, NULL);
return (rc) ? S_OK : HRESULT_FROM_WIN32(GetLastError());
}
virtual HRESULT STDMETHODCALLTYPE Write(void const* pv, ULONG cb, ULONG* pcbWritten)
{
BOOL rc = WriteFile(_hFile, pv, cb, pcbWritten, NULL);
return rc ? S_OK : HRESULT_FROM_WIN32(GetLastError());
}
// IStream Interface
public:
virtual HRESULT STDMETHODCALLTYPE SetSize(ULARGE_INTEGER)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE CopyTo(IStream*, ULARGE_INTEGER, ULARGE_INTEGER*,
ULARGE_INTEGER*)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE Commit(DWORD)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE Revert(void)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE LockRegion(ULARGE_INTEGER, ULARGE_INTEGER, DWORD)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE UnlockRegion(ULARGE_INTEGER, ULARGE_INTEGER, DWORD)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE Clone(IStream **)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE Seek(LARGE_INTEGER liDistanceToMove, DWORD dwOrigin,
ULARGE_INTEGER* lpNewFilePointer)
{
DWORD dwMoveMethod;
switch(dwOrigin)
{
case STREAM_SEEK_SET:
dwMoveMethod = FILE_BEGIN;
break;
case STREAM_SEEK_CUR:
dwMoveMethod = FILE_CURRENT;
break;
case STREAM_SEEK_END:
dwMoveMethod = FILE_END;
break;
default:
return STG_E_INVALIDFUNCTION;
break;
}
if (SetFilePointerEx(_hFile, liDistanceToMove, (PLARGE_INTEGER) lpNewFilePointer,
dwMoveMethod) == 0)
return HRESULT_FROM_WIN32(GetLastError());
return S_OK;
}
virtual HRESULT STDMETHODCALLTYPE Stat(STATSTG* pStatstg, DWORD grfStatFlag)
{
if (GetFileSizeEx(_hFile, (PLARGE_INTEGER) &pStatstg->cbSize) == 0)
return HRESULT_FROM_WIN32(GetLastError());
return S_OK;
}
private:
HANDLE _hFile;
LONG _refcount;
};
......以及explanation正在发生的事情。
答案 3 :(得分：1)
在Delphi中也是如此：
//writes the document to the WideString as UTF-16 (since it's a WideString)
class function TXMLHelper.WriteDocumentToString(
const Document60: DOMDocument60): WideString;
var
writer: IMXWriter;
reader: IVBSAXXMLReader;
bstr: OleVariant;
begin
{
From http://support.microsoft.com/kb/275883
INFO: XML Encoding and DOM Interface Methods
MSXML has native support for the following encodings:
UTF-8
UTF-16
UCS-2
UCS-4
ISO-10646-UCS-2
UNICODE-1-1-UTF-8
UNICODE-2-0-UTF-16
UNICODE-2-0-UTF-8
It also recognizes (internally using the WideCharToMultibyte
API function for mappings) the following encodings:
US-ASCII
ISO-8859-1
ISO-8859-2
ISO-8859-3
ISO-8859-4
ISO-8859-5
ISO-8859-6
ISO-8859-7
ISO-8859-8
ISO-8859-9
WINDOWS-1250
WINDOWS-1251
WINDOWS-1252
WINDOWS-1253
WINDOWS-1254
WINDOWS-1255
WINDOWS-1256
WINDOWS-1257
WINDOWS-1258
}
if Document60 = nil then
raise Exception.Create('TXMLHelper.WriteDocument: Document60 cannot be nil');
// Set properties on the XML writer
// - including BOM, XML declaration and encoding
writer := CoMXXMLWriter60.Create;
writer.byteOrderMark := False; //Don't write the BOM. Has no effect for BSTR output, but still: we don't want it. Determines whether to write the Byte Order Mark (BOM). The byteOrderMark property has no effect for BSTR or DOM output. (Default True)
writer.omitXMLDeclaration := False; //Don't skip the xml declaration. Forces the IMXWriter to skip the XML declaration. Useful for creating document fragments. (Default False)
// writer.encoding := 'UTF-8'; //Sets and gets encoding for the output. (Default "UTF-16")
writer.indent := True; //Sets whether to indent output. (Default False)
writer.standalone := True; //Sets the value of the standalone attribute in the XML declaration to "yes" or "no".
// Set the XML writer to the SAX content handler.
reader := CoSAXXMLReader60.Create;
reader.contentHandler := writer as IVBSAXContentHandler;
reader.dtdHandler := writer as IVBSAXDTDHandler;
reader.errorHandler := writer as IVBSAXErrorHandler;
reader.putProperty('http://xml.org/sax/properties/lexical-handler', writer);
reader.putProperty('http://xml.org/sax/properties/declaration-handler', writer);
// Now pass the DOM through the SAX handler, and it will call the writer
reader.parse(Document60);
// Let the writer do its thing
bstr := writer.output;
Result := bstr;
end;
写一个流的版本：
class procedure TXMLHelper.WriteDocumentToStream(const Document60: DOMDocument60; const stream: IStream; Encoding: string);
var
writer: IMXWriter;
reader: IVBSAXXMLReader;
begin
{
From http://support.microsoft.com/kb/275883
INFO: XML Encoding and DOM Interface Methods
MSXML has native support for the following encodings:
UTF-8
UTF-16
UCS-2
UCS-4
ISO-10646-UCS-2
UNICODE-1-1-UTF-8
UNICODE-2-0-UTF-16
UNICODE-2-0-UTF-8
It also recognizes (internally using the WideCharToMultibyte API function for mappings) the following encodings:
US-ASCII
ISO-8859-1
ISO-8859-2
ISO-8859-3
ISO-8859-4
ISO-8859-5
ISO-8859-6
ISO-8859-7
ISO-8859-8
ISO-8859-9
WINDOWS-1250
WINDOWS-1251
WINDOWS-1252
WINDOWS-1253
WINDOWS-1254
WINDOWS-1255
WINDOWS-1256
WINDOWS-1257
WINDOWS-1258
}
if Document60 = nil then
raise Exception.Create('TXMLHelper.WriteDocument: Document60 cannot be nil');
if stream = nil then
raise Exception.Create('TXMLHelper.WriteDocument: stream cannot be nil');
// Set properties on the XML writer - including BOM, XML declaration and encoding
writer := CoMXXMLWriter60.Create;
writer.byteOrderMark := True; //Determines whether to write the Byte Order Mark (BOM). The byteOrderMark property has no effect for BSTR or DOM output. (Default True)
writer.omitXMLDeclaration := False; //Forces the IMXWriter to skip the XML declaration. Useful for creating document fragments. (Default False)
if Encoding <> '' then
writer.encoding := Encoding; //Sets and gets encoding for the output. (Default "UTF-16")
writer.indent := True; //Sets whether to indent output. (Default False)
writer.standalone := True;
// Set the XML writer to the SAX content handler.
reader := CoSAXXMLReader60.Create;
reader.contentHandler := writer as IVBSAXContentHandler;
reader.dtdHandler := writer as IVBSAXDTDHandler;
reader.errorHandler := writer as IVBSAXErrorHandler;
reader.putProperty('http://xml.org/sax/properties/lexical-handler', writer);
reader.putProperty('http://xml.org/sax/properties/declaration-handler', writer);
writer.output := stream; //The resulting document will be written into the provided IStream
// Now pass the DOM through the SAX handler, and it will call the writer
reader.parse(Document60);
writer.flush;
end;
注意：任何代码都会发布到公共域中。无需归属。
答案 4 :(得分：-1)
C ++：
std::string xmlString = ...
xmlString = "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>" + xmlString
因为，严肃地说，正确的解决方案是一个笑话......