MSXML使用教程

/*++

Copyright (c) 2007 nsfocus information technology

Module Name:

    enumxml.cpp

Abstract:

    枚举foo，打印每个节点的值。

Author:

    xuyibo (xuyibo) 2007-09-22

Revision History:

--*/

#include 
#include 
#pragma comment(lib, "ole32.lib")
#pragma comment(lib, "oleaut32.lib")

IXMLDOMDocument2* LoadXML(WCHAR* pXML)
{
    HRESULT hr;
    IXMLDOMDocument2* pXMLDoc = NULL;
    IXMLDOMParseError* pObjError = NULL;
    BSTR bstr = NULL;
    VARIANT_BOOL status;
    VARIANT vSrc;
    
    //
    // 创建一msxml 文档实例，返回IXMLDOMDocument2接口。
    hr = CoCreateInstance(CLSID_DOMDocument2, 
        NULL, 
        CLSCTX_INPROC_SERVER, 
        __uuidof(IXMLDOMDocument2),
        (void**)&pXMLDoc);
    if (FAILED(hr)) {
        printf("Failed to CoCreate an instance of an XML DOM\n");
        printf("Error code: %x\n", hr);
        goto clean;
    }

    hr = pXMLDoc->put_async(VARIANT_FALSE);
    if (FAILED(hr)) {
        printf("Failed to set async property\n");
        goto clean;
    }

    hr = pXMLDoc->put_validateOnParse(VARIANT_FALSE);
    if (FAILED(hr)) {
        printf("Failed to set validateOnParse\n");
        goto clean;
    }

    hr = pXMLDoc->put_resolveExternals(VARIANT_FALSE);
    if (FAILED(hr)) {
        printf("Failed to disable resolving externals.\n");
        goto clean;
    }

    VariantInit(&vSrc);
    V_BSTR(&vSrc) = SysAllocString(pXML);
    V_VT(&vSrc) = VT_BSTR;

    //
    // 读取foo.xml
    hr = pXMLDoc->load(vSrc, &status);

    if (status!=VARIANT_TRUE) {
        hr = pXMLDoc->get_parseError(&pObjError);
        hr = pObjError->get_reason(&bstr);
        printf("Failed to load DOM from books.xml. %S\n",bstr);
        goto clean;
    }
    
clean:
    if (bstr)
        SysFreeString(bstr);
    if (&vSrc) 
        VariantClear(&vSrc);
    if (pObjError)
        pObjError->Release();
    
    return pXMLDoc;
}

void Dump(BSTR pData)
{
    char Buffer[512];
    
    WideCharToMultiByte(CP_ACP, WC_COMPOSITECHECK, pData,
			-1, Buffer, sizeof(Buffer), NULL, NULL);
    puts(Buffer);
}

int main(int argc, char* argv[])
{
    HRESULT hr;
    IXMLDOMDocument2* pXMLDoc = NULL;
    IXMLDOMNodeList* pNodeList = NULL;
    IXMLDOMNode* Node;
    IXMLDOMNamedNodeMap* NodeMap;
    IXMLDOMNode* IDNode;
    long I;
    long Length;
    BSTR BStr;
	BSTR BStrValue;

    //
    // First we must call CoInitialize.
    //
    
    CoInitialize(NULL);

    //
    // Load xml.
    //
    
    pXMLDoc = LoadXML(L"foo.xml");
    if (pXMLDoc == NULL) {
        return 1;
    }

    if (pXMLDoc->selectNodes(L"//root/item", &pNodeList) != S_OK) {
        return 1;
    }
    
    hr = pNodeList->get_length(&Length);
    if (FAILED(hr)) {
        return 1;
    }
    
    for (I = 0; I < Length; i++) {
        if (pNodeList->get_item(I, &Node) == S_OK) {
            
            //
            // Dump text => Hello MSXML
            //
                
            if (Node->get_text(&BStr) == S_OK) {
                Dump(BStr);
            }
            
            if (Node->get_attributes(&NodeMap) == S_OK) {
                if (NodeMap->getNamedItem(L"id", &IDNode) == S_OK) {
                    
                    //
                    // Dump id => 1
                    //
                    
                    if (IDNode->get_text(&BStrValue) == S_OK) {
                        Dump(BStrValue);
                        puts("");
                        SysFreeString(BStrValue);
                    }
                    IDNode->Release();
                }
                NodeMap->Release();
            }
            
            SysFreeString(BStr);
            Node->Release();
        }   
    }
    
    pXMLDoc->Release();

    //
    // Finally we should call CoUninitialize
    //
    
    CoUninitialize();

    getchar();
    return 0;
}