使用MsXML存取XML(2).docx

使用MsXML存取XML（2）与JavaScript相比而言，在C+中调用COM比较麻烦，MsXML库是一组COM动态库，这意味Visual C+应用程序必须以COM调用方式调用MsXML组件。下面是实现存取persons.xml文件的Visual C+版本。需要导入“msxml4.dll”组件库【程序 6-8】使用MsXML读写XML文件1. 01 #include stdafx.h 2. 02 #include comutil.h 3. 03 #include 4. 04 5. 05 #import msxml4.dll 6. 06 7. 07 void WritePerson(MSXML2:IXMLDOMDocument2Ptr pDocument, 8. MSXML2:IXMLDOMNodePtr pParentNode, CString name, long age) 9. 08 10. 09 /创建一个节点 11. 10 MSXML2:IXMLDOMElementPtr pPersonNode = pDocument-createElement(_T(person); 12. 11 pParentNode-appendChild(pPersonNode); 13. 12 14. 13 /写入name 15. 14 MSXML2:IXMLDOMElementPtr pPersonNameNode = pDocument-createElement(_T(name); 16. 15 pPersonNameNode-text = _bstr_t(name); 17. 16 18. 17 /写入age 19. 18 MSXML2:IXMLDOMElementPtr pPersonAgeNode = pDocument-createElement(_T(age); 20. 19 pPersonAgeNode-text = _bstr_t(age); 21. 20 22. 21 pPersonNode-appendChild(pPersonNameNode); 23. 22 pPersonNode-appendChild(pPersonAgeNode); 24. 23 25. 24 26. 25 void WritePersons() 27. 26 28. 27 MSXML2:IXMLDOMDocument2Ptr pXMLDocument; 29. 28 pXMLDocument.CreateInstance(_uuidof(MSXML2:DOMDocument); 30. 29 MSXML2:IXMLDOMElementPtr pPersonsNode = 31. pXMLDocument-createElement(_T(persons); 32. 30 pXMLDocument-appendChild(pPersonsNode); 33. 31 34. 32 WritePerson(pXMLDocument, pPersonsNode, _T(佟湘玉), 28); 35. 33 WritePerson(pXMLDocument, pPersonsNode, _T(白展堂), 27); 36. 34 37. 35 pXMLDocument-save(_T(persons.xml); 38. 36 39. 37 40. 38 void ReadPersons() 41. 39 42. 40 MSXML2:IXMLDOMDocument2Ptr pXMLDocument; 43. 41 pXMLDocument.CreateInstance(_uuidof(MSXML2:DOMDocument); 44. 42 45. 43 pXMLDocument-load(_T(persons.xml); 46. 44 47. 45 MSXML2:IXMLDOMElementPtr pRootNode = pXMLDocument-documentElement; 48. 46 /查找节点 49. 47 MSXML2:IXMLDOMNodeListPtr pPersonNodes = pRootNode-selectNodes(_T(person); 50. 48 51. 49 CString s; 52. 50 long size = pPersonNodes-length; 53. 51 54. 52 for(int i = 0; i itemi; 57. 55 58. 56 MSXML2:IXMLDOMNodePtr pNameNode = pPersonNode-selectSingleNode(_T(name); 59. 57 MSXML2:IXMLDOMNodePtr pAgeNode =pPersonNode-selectSingleNode(_T(age); 60. 58 61. 59 s.Format(_T(%sname: %stage: %srn), s, (LPCTSTR)pNameNode- 62. text, (LPCTSTR)pAgeNode-text); 63. 60 64. 61 65. 62 _tprintf(s); 66. 63 67. 64 68. 65 int _tmain() 69. 66 70. 67 setlocale(LC_ALL, chs); 71. 68 72. 69 HRESULT hr; 73. 70 hr = :CoInitialize(NULL); 74. 71 75. 72 WritePersons(); 76. 73 ReadPersons(); 77. 74 78. 75 :CoUninitialize(); 79. 76 return 0;77 运行结果如图6-27所示。图6-27 运行结果在Visual C+中，调用COM组件比较省力、安全的办法是使用#import方式。另外，MsXML的版本不同，其提供的DLL文件名也不同，如MSXML 4.0对应的DLL为msxml4.dll。细心的读者可能会发现，一旦在程序中导入了msxml4.dll并build（生成）一次项目，在程序中就可以自动引入一些类，如：MSXML2:IXMLDOMDocument2Ptr，MSXML2是一个C+名字空间，IXMLDOMDocument2Ptr则是一个封装了IXMLDOMDocument对象操