用CComPtr<IXMLDOMDocument> (C++)保存XML头

Question

我使用atl和CComPtr，如下所示：

CComPtr<IXMLDOMDocument> xml_doc;
HRESULT hr = xml_doc.CoCreateInstance(__uuidof(DOMDocument))
...
HRESULT hr = xml_doc->createElement(CComBSTR(element_name.c_str()), &element);
...
etc

当我调用xml_doc->save时，它会保存没有标题的xml。添加标题的最简单方法是什么？

Answer 1

已解决：

HRESULT hr;

CComPtr<IXMLDOMProcessingInstruction> proc_instr;
hr = xml_out->createProcessingInstruction(L"xml", L"version=\"1.0\" encoding=\"UTF-8\"", &proc_instr);
if (FAILED(hr))
    throw std::exception("Failed to create IXMLDOMDocument processing instruction");


CComPtr<IXMLDOMNode> first_child;
hr = xml_out->get_firstChild(&first_child);
if (FAILED(hr))
    throw std::exception("Failed to get first child of IXMLDOMDocument");

hr = xml_out->insertBefore(proc_instr, CComVariant(first_child), NULL);
if (FAILED(hr))
    throw std::exception("Failed to insert IXMLDOMDocument processing instruction");


hr = xml_out->save(CComVariant(header->output_file.c_str()));
if (FAILED(hr))
    throw std::exception("Failed to save response XML to '" + header->output_file + "'");

http://msdn.microsoft.com/en-us/library/windows/desktop/ms755439(v=vs.85).aspx