ZC: 这里的代码，就是 http://www.cnblogs.com/cppskill/p/6207609.html(我的文章"XML_CPP_资料_libXml2_01 - CppSkill - 博客园.html")里面的代码...
1、创建xml文档
1.1、CreateXmlFile.cpp
/******************************************************************** created: 2007/11/09 created: 9:11:2007 15:34 filename: CreateXmlFile.cpp author: Wang xuebin depend: libxml2.lib build: nmake TARGET_NAME=CreateXmlFile purpose: 创建一个xml文件 *********************************************************************/ #include <stdio.h> #include <libxml/parser.h> #include <libxml/tree.h> #include <iostream.h> int main() { //定义文档和节点指针 xmlDocPtr doc = xmlNewDoc(BAD_CAST"1.0"); xmlNodePtr root_node = xmlNewNode(NULL,BAD_CAST"root"); //设置根节点 xmlDocSetRootElement(doc,root_node); //在根节点中直接创建节点 xmlNewTextChild(root_node, NULL, BAD_CAST "newNode1", BAD_CAST "newNode1 content"); xmlNewTextChild(root_node, NULL, BAD_CAST "newNode2", BAD_CAST "newNode2 content"); xmlNewTextChild(root_node, NULL, BAD_CAST "newNode3", BAD_CAST "newNode3 content"); //创建一个节点，设置其内容和属性，然后加入根结点 xmlNodePtr node = xmlNewNode(NULL,BAD_CAST"node2"); xmlNodePtr content = xmlNewText(BAD_CAST"NODE CONTENT"); xmlAddChild(root_node,node); xmlAddChild(node,content); xmlNewProp(node,BAD_CAST"attribute",BAD_CAST "yes"); //创建一个儿子和孙子节点 node = xmlNewNode(NULL, BAD_CAST "son"); xmlAddChild(root_node,node); xmlNodePtr grandson = xmlNewNode(NULL, BAD_CAST "grandson"); xmlAddChild(node,grandson); xmlAddChild(grandson, xmlNewText(BAD_CAST "This is a grandson node")); //存储xml文档 int nRel = xmlSaveFile("CreatedXml.xml",doc); if (nRel != -1) { cout<<"一个xml文档被创建,写入"<<nRel<<"个字节"<<endl; } //释放文档内节点动态申请的内存 xmlFreeDoc(doc); return 1; }
1.2、CreatedXml.xml
<?xml version="1.0"?> <root> <newNode1>newNode1 content</newNode1> <newNode2>newNode2 content</newNode2> <newNode3>newNode3 content</newNode3> <node2 attribute="yes">NODE CONTENT</node2> <son> <grandson>This is a grandson node</grandson> </son> </root>
2、解析xml文档
2.1、ParseXmlFile.cpp
/******************************************************************** created: 2007/11/15 created: 15:11:2007 11:47 filename: ParseXmlFile.cpp author: Wang xuebin depend: libxml2.lib build: nmake TARGET_NAME=ParseXmlFile purpose: 解析xml文件 *********************************************************************/ #include <libxml/parser.h> #include <iostream.h> int main(int argc, char* argv[]) { xmlDocPtr doc; //定义解析文档指针 xmlNodePtr curNode; //定义结点指针(你需要它为了在各个结点间移动) xmlChar *szKey; //临时字符串变量 char *szDocName; if (argc <= 1) { printf("Usage: %s docname ", argv[0]); return(0); } szDocName = argv[1]; doc = xmlReadFile(szDocName,"GB2312",XML_PARSE_RECOVER); //解析文件 //检查解析文档是否成功，如果不成功，libxml将指一个注册的错误并停止。 //一个常见错误是不适当的编码。XML标准文档除了用UTF-8或UTF-16外还可用其它编码保存。 //如果文档是这样，libxml将自动地为你转换到UTF-8。更多关于XML编码信息包含在XML标准中. if (NULL == doc) { fprintf(stderr,"Document not parsed successfully. "); return -1; } curNode = xmlDocGetRootElement(doc); //确定文档根元素 /*检查确认当前文档中包含内容*/ if (NULL == curNode) { fprintf(stderr,"empty document "); xmlFreeDoc(doc); return -1; } /*在这个例子中，我们需要确认文档是正确的类型。“root”是在这个示例中使用文档的根类型。*/ if (xmlStrcmp(curNode->name, BAD_CAST "root")) { fprintf(stderr,"document of the wrong type, root node != root"); xmlFreeDoc(doc); return -1; } curNode = curNode->xmlChildrenNode; xmlNodePtr propNodePtr = curNode; while(curNode != NULL) { //取出节点中的内容 if ((!xmlStrcmp(curNode->name, (const xmlChar *)"newNode1"))) { szKey = xmlNodeGetContent(curNode); printf("newNode1: %s ", szKey); xmlFree(szKey); } //查找带有属性attribute的节点 if (xmlHasProp(curNode,BAD_CAST "attribute")) { propNodePtr = curNode; } curNode = curNode->next; } //查找属性 xmlAttrPtr attrPtr = propNodePtr->properties; while (attrPtr != NULL) { if (!xmlStrcmp(attrPtr->name, BAD_CAST "attribute")) { xmlChar* szAttr = xmlGetProp(propNodePtr,BAD_CAST "attribute"); cout<<"get attribute = "<<szAttr<<endl; xmlFree(szAttr); } attrPtr = attrPtr->next; } xmlFreeDoc(doc); return 0; }
2.2、ParseXmlFile.exe CreatedXml.xml
3、修改xml文档
3.1、ChangeXmlFile.cpp
/******************************************************************** created: 2007/11/15 created: 15:11:2007 15:20 filename: ChangeXmlFile.cpp author: Wang xuebin depend: libxml2.lib build: nmake TARGET_NAME=ChangeXmlFile purpose: 修改XML元素及属性 *********************************************************************/ #include <libxml/parser.h> #include <iostream.h> int main(int argc, char* argv[]) { xmlDocPtr doc; //定义解析文档指针 xmlNodePtr curNode; //定义结点指针(你需要它为了在各个结点间移动) char *szDocName; if (argc <= 1) { printf("Usage: %s docname ", argv[0]); return(0); } szDocName = argv[1]; doc = xmlReadFile(szDocName,"GB2312",XML_PARSE_RECOVER); //解析文件 if (NULL == doc) { fprintf(stderr,"Document not parsed successfully. "); return -1; } curNode = xmlDocGetRootElement(doc); /*检查确认当前文档中包含内容*/ if (NULL == curNode) { fprintf(stderr,"empty document "); xmlFreeDoc(doc); return -1; } curNode = curNode->children; while (NULL != curNode) { //删除newNode1 if (!xmlStrcmp(curNode->name, BAD_CAST "newNode1")) { xmlNodePtr tempNode; tempNode = curNode->next; xmlUnlinkNode(curNode); xmlFreeNode(curNode); curNode = tempNode; continue; } //修改node2的属性值 if (!xmlStrcmp(curNode->name, BAD_CAST "node2")) { xmlSetProp(curNode,BAD_CAST "attribute", BAD_CAST "no"); } //修改newNode2的内容 if (!xmlStrcmp(curNode->name, BAD_CAST "newNode2")) { xmlNodeSetContent(curNode, BAD_CAST "content changed"); } //增加一个属性 if (!xmlStrcmp(curNode->name, BAD_CAST "newNode3")) { xmlNewProp(curNode, BAD_CAST "newAttr", BAD_CAST "YES"); } //增加一个子节点 if (!xmlStrcmp(curNode->name, BAD_CAST "son")) { xmlNewTextChild(curNode, NULL, BAD_CAST "newGrandSon", BAD_CAST "new content"); } curNode = curNode->next; } //存储xml文档 int nRel = xmlSaveFile("ChangedXml.xml",doc); if (nRel != -1) { cout<<"一个xml文档被创建,写入"<<nRel<<"个字节"<<endl; } xmlFreeDoc(doc); return 0; }
3.2、ChangedXml.xml （ChangeXmlFile.exe CreatedXml.xml）
<?xml version="1.0"?> <root> <newNode2>content changed</newNode2> <newNode3 newAttr="YES">newNode3 content</newNode3> <node2 attribute="no">NODE CONTENT</node2> <son> <grandson>This is a grandson node</grandson> <newGrandSon>new content</newGrandSon></son> </root>
4、使用XPATH查找xml文档
4.1、XPathForXmlFile.cpp
/******************************************************************** created: 2007/11/15 created: 15:11:2007 16:01 filename: XpathForXmlFile.cpp author: Wang xuebin depend: libxml2.lib build: nmake TARGET_NAME=XPathForXmlFile purpose: 使用XPATH查找xml文档中的节点 *********************************************************************/ #include <libxml/parser.h> #include <libxml/xpath.h> #include <iostream.h> xmlXPathObjectPtr get_nodeset(xmlDocPtr doc, const xmlChar *szXpath) { xmlXPathContextPtr context; //XPATH上下文指针 xmlXPathObjectPtr result; //XPATH对象指针，用来存储查询结果 context = xmlXPathNewContext(doc); //创建一个XPath上下文指针 if (context == NULL) { printf("context is NULL "); return NULL; } result = xmlXPathEvalExpression(szXpath, context); //查询XPath表达式，得到一个查询结果 xmlXPathFreeContext(context); //释放上下文指针 if (result == NULL) { printf("xmlXPathEvalExpression return NULL "); return NULL; } if (xmlXPathNodeSetIsEmpty(result->nodesetval)) //检查查询结果是否为空 { xmlXPathFreeObject(result); printf("nodeset is empty "); return NULL; } return result; } int main(int argc, char* argv[]) { xmlDocPtr doc = NULL; //定义解析文档指针 xmlNodePtr curNode = NULL; //定义结点指针(你需要它为了在各个结点间移动) char *szDocName = NULL; if (argc <= 1) { printf("Usage: %s docname ", argv[0]); return(0); } szDocName = argv[1]; doc = xmlReadFile(szDocName,"GB2312",XML_PARSE_RECOVER); //解析文件 if (NULL == doc) { fprintf(stderr,"Document not parsed successfully. "); return -1; } xmlChar *szXpath =BAD_CAST ("/root/node2[@attribute='yes']"); xmlXPathObjectPtr app_result = get_nodeset(doc,szXpath); //查询并得到结果 if (NULL == app_result) { printf("app_result is NULL "); return -1; } xmlChar *szValue = NULL; if(app_result) { xmlNodeSetPtr nodeset = app_result->nodesetval; for (int i = 0; i < nodeset->nodeNr; i++) { curNode = nodeset->nodeTab[i]; if(curNode != NULL) { szValue = xmlGetProp(curNode,BAD_CAST "attribute"); if (szValue != NULL) { printf("attribute = %s ", szValue); xmlFree(szValue); } szValue = xmlNodeGetContent(curNode); if (szValue != NULL) { printf("content = %s ", szValue); xmlFree(szValue); } } } xmlXPathFreeObject (app_result); } xmlFreeDoc(doc); return 0; }
4.2、XpathForXmlFile.exe CreatedXml.xml
5、用ICONV解决XML中的中文问题
5.1、wxb_codeConv.c
/******************************************************************** created: 2007/11/15 created: 15:11:2007 10:30 filename: wxb_codeConv.c author: Wang xuebin depend: iconv.lib build: 不需要build，被包含到其它源代码中 purpose: 提供从UTF-8到GB2312的内码转换，以及反向的转换 *********************************************************************/ #include "iconv.h" #include <string.h> //代码转换:从一种编码转为另一种编码 int code_convert(char* from_charset, char* to_charset, char* inbuf, int inlen, char* outbuf, int outlen) { iconv_t cd; char** pin = &inbuf; char** pout = &outbuf; cd = iconv_open(to_charset,from_charset); if(cd == 0) return -1; memset(outbuf,0,outlen); if(iconv(cd,(const char**)pin,(unsigned int *)&inlen,pout,(unsigned int*)&outlen) == -1) return -1; iconv_close(cd); return 0; } //UNICODE码转为GB2312码 //成功则返回一个动态分配的char*变量，需要在使用完毕后手动free，失败返回NULL char* u2g(char *inbuf) { int nOutLen = 2 * strlen(inbuf) - 1; char* szOut = (char*)malloc(nOutLen); if (-1 == code_convert("utf-8","gb2312",inbuf,strlen(inbuf),szOut,nOutLen)) { free(szOut); szOut = NULL; } return szOut; } //GB2312码转为UNICODE码 //成功则返回一个动态分配的char*变量，需要在使用完毕后手动free，失败返回NULL char* g2u(char *inbuf) { int nOutLen = 2 * strlen(inbuf) - 1; char* szOut = (char*)malloc(nOutLen); if (-1 == code_convert("gb2312","utf-8",inbuf,strlen(inbuf),szOut,nOutLen)) { free(szOut); szOut = NULL; } return szOut; }
5.2、CreateXmlFile_cn.cpp
/******************************************************************** created: 2007/11/17 created: 9:11:2007 15:34 filename: CreateXmlFile.cpp author: Wang xuebin depend: libxml2.lib iconv.lib build: nmake TARGET_NAME=CreateXmlFile_cn purpose: 创建一个xml文件，其中包含中文 *********************************************************************/ #include <stdio.h> #include <libxml/parser.h> #include <libxml/tree.h> #include <iostream.h> #include "wxb_codeConv.c" //自己写的编码转换函数 int main(int argc, char **argv) { //定义文档和节点指针 xmlDocPtr doc = xmlNewDoc(BAD_CAST"1.0"); xmlNodePtr root_node = xmlNewNode(NULL,BAD_CAST"root"); //设置根节点 xmlDocSetRootElement(doc,root_node); //一个中文字符串转换为UTF-8字符串，然后写入 char* szOut = g2u("节点1的内容"); //在根节点中直接创建节点 xmlNewTextChild(root_node, NULL, BAD_CAST "newNode1", BAD_CAST "newNode1 content"); xmlNewTextChild(root_node, NULL, BAD_CAST "newNode2", BAD_CAST "newNode2 content"); xmlNewTextChild(root_node, NULL, BAD_CAST "newNode3", BAD_CAST "newNode3 content"); xmlNewChild(root_node, NULL, BAD_CAST "node1",BAD_CAST szOut); free(szOut); //创建一个节点，设置其内容和属性，然后加入根结点 xmlNodePtr node = xmlNewNode(NULL,BAD_CAST"node2"); xmlNodePtr content = xmlNewText(BAD_CAST"NODE CONTENT"); xmlAddChild(root_node,node); xmlAddChild(node,content); szOut = g2u("属性值"); xmlNewProp(node,BAD_CAST"attribute",BAD_CAST szOut); free(szOut); //创建一个中文节点 szOut = g2u("中文节点"); xmlNewChild(root_node, NULL, BAD_CAST szOut,BAD_CAST "content of chinese node"); free(szOut); //存储xml文档 int nRel = xmlSaveFormatFileEnc("CreatedXml_cn.xml",doc,"GB2312",1); if (nRel != -1) { cout<<"一个xml文档被创建,写入"<<nRel<<"个字节"<<endl; } xmlFreeDoc(doc); return 1; }
5.3、CreatedXml_cn.xml
<?xml version="1.0" encoding="GB2312"?> <root> <newNode1>newNode1 content</newNode1> <newNode2>newNode2 content</newNode2> <newNode3>newNode3 content</newNode3> <node1>节点1的内容</node1> <node2 attribute="属性值">NODE CONTENT</node2> <中文节点>content of chinese node</中文节点> </root>
6、用XML来做点什么
6.1、1.xml
<?xml version="1.0" encoding="GB2312"?> <root> <My_Program_Code content="1"></My_Program_Code> </root>
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