VC++ 创建 XML文件时总是报appendChild()找不到?

Question

我使用VS2015/VC++来建立一个XML文件，首先引入了msxml6, 然后参考了微软的示例代码如下:

import "msxml6.dll"
using namespace MSXML2;

主循环里的代码如下:

MSXML2::IXMLDOMDocumentPtr pXMLDom; 
HRESULT hr = pXMLDom.CreateInstance(__uuidof(MSXML2::DOMDocument60), NULL,     CLSCTX_INPROC_SERVER);

if (FAILED(hr))
{
    printf("Failed to instantiate an XML DOM.\n");
    return;
}

try
{
    pXMLDom->async = VARIANT_FALSE;
    pXMLDom->validateOnParse = VARIANT_FALSE;
    pXMLDom->resolveExternals = VARIANT_FALSE;
    pXMLDom->preserveWhiteSpace = VARIANT_TRUE;

    // Create a processing instruction targeted for xml.
    MSXML2::IXMLDOMProcessingInstructionPtr pi =       pXMLDom->createProcessingInstruction(L"xml", L"version='1.0'");    
    **pXMLDom->appendChild(pi);**

    // Create a comment for the document.
    MSXML2::IXMLDOMCommentPtr pc = pXMLDom->createComment(L"sample xml file created using XML DOM object.");
    **pXMLDom->appendChild(pc);**

...... }

但是VS2015总是报class "MSXML2::IXMLDOMDocument" 没有成员 "appendChild". 编译是也是报错，网上查夜查不到答案。有没有人知道为什么?