Borland C++ Builder 6.0 XML处理总结
1、安装
C++ Builder对于XML处理主要封装在TXMLDocument组件中，该组件是Internet组件的一部分。
如果在安装包有已经有Borland Internet Components组件，那表示已经可以使用
TXMLDocument控件了。该控件在Internet控制卡中，笔者的在最后一个，图标为标识有XML
的文档式样。如果没有该控件的话，你需要安装。
TXMLDocument不是C++ Builder缺省安装的包，需要自己添加安装包。如果在C++ Builder
目录的Bin目录下存在dclnet60.bpl文件，就直接安装就是，否则需要修改安装，以安装该
组件包。
2、使用
2.1 基本操作
2.1.1 使用控件方式加载XML文件示例:
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//加载XML文件
OpenDialog1->Filter = "XML(程序配置文件)|*.xml";
if (!OpenDialog1->Execute()){
return;
}
XMLDoc->LoadFromFile(OpenDialog1->FileName);
_di_IXMLNode node = XMLDoc->DocumentElement;
if (node == NULL){
ShowMessage("不是合法的程序配置文件XML文件格式。");
return;
}
//加载XML文件
OpenDialog1->Filter = "XML(程序配置文件)|*.xml";
if (!OpenDialog1->Execute()){
return;
}
XMLDoc->LoadFromFile(OpenDialog1->FileName);
_di_IXMLNode node = XMLDoc->DocumentElement;
if (node == NULL){
ShowMessage("不是合法的程序配置文件XML文件格式。");
return;
}
2.1.2 使用控件方式保存XML文件示例：
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SaveDialog1->FileName = FDevTypeName + ".xml";
SaveDialog1->Filter = "XML(程序配置文件)|*.xml";
if (SaveDialog1->Execute()){
XMLDoc->Active=true;
XMLDoc->Version = "1.0";
XMLDoc->Encoding = "GB2312";
XMLDoc->Options << doNodeAutoIndent;
//建立文档主元素
XMLDoc->DocumentElement = XMLDoc->CreateElement("Config", "");
XMLDoc->DocumentElement->SetAttribute("DevType", FDevTypeName);
//从UI更新XML数据
UpdateXMLDataFromUI(XMLDoc->DocumentElement);
//格式化XML
XMLDoc->LoadFromXML(formatXMLDoc(XMLDoc, 1));
//保存XML文件
XMLDoc->SaveToFile(SaveDialog1->FileName);
ShowMessage("保存配置"+ SaveDialog1->FileName + "文件成功");
}
SaveDialog1->FileName = FDevTypeName + ".xml";
SaveDialog1->Filter = "XML(程序配置文件)|*.xml";
if (SaveDialog1->Execute()){
XMLDoc->Active=true;
XMLDoc->Version = "1.0";
XMLDoc->Encoding = "GB2312";
XMLDoc->Options << doNodeAutoIndent;
//建立文档主元素
XMLDoc->DocumentElement = XMLDoc->CreateElement("Config", "");
XMLDoc->DocumentElement->SetAttribute("DevType", FDevTypeName);
//从UI更新XML数据
UpdateXMLDataFromUI(XMLDoc->DocumentElement);
//格式化XML
XMLDoc->LoadFromXML(formatXMLDoc(XMLDoc, 1));
//保存XML文件
XMLDoc->SaveToFile(SaveDialog1->FileName);
ShowMessage("保存配置"+ SaveDialog1->FileName + "文件成功");
}
2.2 读
2.2.1 读取节点数据
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AnsiString GetNodeData(_di_IXMLNode panode,
AnsiString nodename, AnsiString defaultvalue)
{
//取得子节点列表
_di_IXMLNodeList nodes = panode->ChildNodes;
//从子节点列表查找节点
_di_IXMLNode node = nodes->FindNode(nodename);
if (node == NULL){
return defaultvalue;
}
//从节点取得数据
return node->GetText();
}
AnsiString GetNodeData(_di_IXMLNode panode,
AnsiString nodename, AnsiString defaultvalue)
{
//取得子节点列表
_di_IXMLNodeList nodes = panode->ChildNodes;
//从子节点列表查找节点
_di_IXMLNode node = nodes->FindNode(nodename);
if (node == NULL){
return defaultvalue;
}
//从节点取得数据
return node->GetText();
}
2.2.1 读取节点属性
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//在格式描述XML文件中定位列描述
nodename = "grid";
_di_IXMLNode uinode = XMLUI->DocumentElement;
_di_IXMLNodeList uinodelst = uinode->ChildNodes;
uinode = uinodelst->FindNode(nodename);
uinodelst = uinode->ChildNodes;
for (jdx = 0; jdx < uinodelst->Count; jdx++){
//取得当前列在表格中的位置
colname = uinodelst->Nodes[jdx]->GetText();
//设置列头
colheader = colname + "(" + uinodelst->Nodes[jdx]->GetAttribute("length") ;
//根据类型设置表格列类型，用于编辑
//取得节点属性示例
if (AnsiString(uinodelst->Nodes[jdx]->GetAttribute("type")) == AnsiString("Hex")){
colheader += ", Hex";
}else if (AnsiString(uinodelst->Nodes[jdx]->GetAttribute("type")) == AnsiString("DevType")){
}else if (AnsiString(uinodelst->Nodes[jdx]->GetAttribute("type")) == AnsiString("Baud")){
}else if (AnsiString(uinodelst->Nodes[jdx]->GetAttribute("type")) == AnsiString("Integer")){
colheader += ", Dec";
}else{
colheader += ", Dec";
}
colheader += ")";
//...(省略)
}//~for(jdx...
//在格式描述XML文件中定位列描述
nodename = "grid";
_di_IXMLNode uinode = XMLUI->DocumentElement;
_di_IXMLNodeList uinodelst = uinode->ChildNodes;
uinode = uinodelst->FindNode(nodename);
uinodelst = uinode->ChildNodes;
for (jdx = 0; jdx < uinodelst->Count; jdx++){
//取得当前列在表格中的位置
colname = uinodelst->Nodes[jdx]->GetText();
//设置列头
colheader = colname + "(" + uinodelst->Nodes[jdx]->GetAttribute("length") ;
//根据类型设置表格列类型，用于编辑
//取得节点属性示例
if (AnsiString(uinodelst->Nodes[jdx]->GetAttribute("type")) == AnsiString("Hex")){
colheader += ", Hex";
}else if (AnsiString(uinodelst->Nodes[jdx]->GetAttribute("type")) == AnsiString("DevType")){
}else if (AnsiString(uinodelst->Nodes[jdx]->GetAttribute("type")) == AnsiString("Baud")){
}else if (AnsiString(uinodelst->Nodes[jdx]->GetAttribute("type")) == AnsiString("Integer")){
colheader += ", Dec";
}else{
colheader += ", Dec";
}
colheader += ")";
//...(省略)
}//~for(jdx...
2.3 写
以下代码演示了如果添加子节点，以及设置属性，写XML文件在第1节点有所描述。
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void UpdateNodeData(_di_IXMLNode panode,
AnsiString nodename, AnsiString value, AnsiString friendlyname)
{
_di_IXMLNodeList nodes = panode->ChildNodes;
_di_IXMLNode node = nodes->FindNode(nodename);
if (node == NULL){
//添加子节点
node = panode->AddChild(nodename);
//设置属性
node->SetAttribute("FriendlyName", friendlyname);
}
//改变节点数据
node->SetText(value);
}
void UpdateNodeData(_di_IXMLNode panode,
AnsiString nodename, AnsiString value, AnsiString friendlyname)
{
_di_IXMLNodeList nodes = panode->ChildNodes;
_di_IXMLNode node = nodes->FindNode(nodename);
if (node == NULL){
//添加子节点
node = panode->AddChild(nodename);
//设置属性
node->SetAttribute("FriendlyName", friendlyname);
}
//改变节点数据
node->SetText(value);
}
2.4 格式化XML
以上代码为格式化XML，调用方式在写XML在2.1.2节中有描述。使用该组件的缩进方式直接
通过写入节点方式并不能得到格式化文档，当加载一个文件时可以自动格式化。一种简单的
格式化方式就是先保存好文件再读取一次，再保存就可以得到格式化的文档。
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//声明：该代码源于网络，并做了些修改
//---------------------------------------------------------------------------
//格式化XML文档
//---------------------------------------------------------------------------
AnsiString formatXMLDoc(TXMLDocument* doc, int indent)
{
AnsiString sRes;
int i;
sRes = "<?xml version=\"" + doc->Version + "\" encoding=\"" + doc->Encoding + "\"?>\r\n";
sRes += "<" + doc->DocumentElement->NodeName;
for (i = 0; i < doc->DocumentElement->AttributeNodes->Count; i++)
{
sRes += " " + doc->DocumentElement->AttributeNodes->Nodes[i]->NodeName
+ "=\"" + doc->DocumentElement->AttributeNodes->Nodes[i]->NodeValue + "\"";
}
sRes += ">\r\n";
for (i = 0; i < doc->DocumentElement->ChildNodes->Count; ++i){
sRes += formatXMLNode(doc->DocumentElement->ChildNodes->Nodes[i], indent);
}
sRes += "</" + doc->DocumentElement->NodeName + ">\r\n";
return sRes;
}
AnsiString formatXMLNode(_di_IXMLNode element, int indent)
{
AnsiString sBlank = "";
AnsiString sRes = "";
int i;
for (i = 0; i < indent; ++i){
sBlank += " ";
}
if (element->NodeType == ELEMENT_NODE
&& element->ChildNodes && element->ChildNodes->Count > 0
&& element->ChildNodes->Nodes[0]->NodeType != TEXT_NODE)
{
sRes = sBlank + '<'+element->NodeName;
for (i = 0; i < element->AttributeNodes->Count; i++)
{
sRes += " " + element->AttributeNodes->Nodes[i]->NodeName
+ "=\"" + element->AttributeNodes->Nodes[i]->NodeValue + "\"";
}
sRes += ">\r\n";
indent++;
for (i = 0; i < element->ChildNodes->Count; i++)
{
sRes += formatXMLNode(element->ChildNodes->Nodes[i], indent);
}
sRes += sBlank + "</" + element->NodeName + ">\r\n";
}
else if (element->NodeType != PROCESSING_INSTRUCTION_NODE)
{
sRes += sBlank + element->XML + "\r\n";
}
return sRes;
}
//声明：该代码源于网络，并做了些修改
//---------------------------------------------------------------------------
//格式化XML文档
//---------------------------------------------------------------------------
AnsiString formatXMLDoc(TXMLDocument* doc, int indent)
{
AnsiString sRes;
int i;
sRes = "<?xml version=\"" + doc->Version + "\" encoding=\"" + doc->Encoding + "\"?>\r\n";
sRes += "<" + doc->DocumentElement->NodeName;
for (i = 0; i < doc->DocumentElement->AttributeNodes->Count; i++)
{
sRes += " " + doc->DocumentElement->AttributeNodes->Nodes[i]->NodeName
+ "=\"" + doc->DocumentElement->AttributeNodes->Nodes[i]->NodeValue + "\"";
}
sRes += ">\r\n";
for (i = 0; i < doc->DocumentElement->ChildNodes->Count; ++i){
sRes += formatXMLNode(doc->DocumentElement->ChildNodes->Nodes[i], indent);
}
sRes += "</" + doc->DocumentElement->NodeName + ">\r\n";
return sRes;
}
AnsiString formatXMLNode(_di_IXMLNode element, int indent)
{
AnsiString sBlank = "";
AnsiString sRes = "";
int i;
for (i = 0; i < indent; ++i){
sBlank += " ";
}
if (element->NodeType == ELEMENT_NODE
&& element->ChildNodes && element->ChildNodes->Count > 0
&& element->ChildNodes->Nodes[0]->NodeType != TEXT_NODE)
{
sRes = sBlank + '<'+element->NodeName;
for (i = 0; i < element->AttributeNodes->Count; i++)
{
sRes += " " + element->AttributeNodes->Nodes[i]->NodeName
+ "=\"" + element->AttributeNodes->Nodes[i]->NodeValue + "\"";
}
sRes += ">\r\n";
indent++;
for (i = 0; i < element->ChildNodes->Count; i++)
{
sRes += formatXMLNode(element->ChildNodes->Nodes[i], indent);
}
sRes += sBlank + "</" + element->NodeName + ">\r\n";
}
else if (element->NodeType != PROCESSING_INSTRUCTION_NODE)
{
sRes += sBlank + element->XML + "\r\n";
}
return sRes;
}
3、注意事项
以上描述的方式是通过XML控件方式来操作XML文档。在使用对象方式操作XML文件时，需要注意一些问题。
在加载一个文件时，不需要创建一个TXMLDocument对象（TXMLDocument *myxml = new TXMLDocument()），
而是使用_di_IXMLDocument接口。从文件加载XML文件是使用LoadXMLDocument来获得该接口的实例。操作
一个空的XML文档并开始写时也是使用该接口NewXMLDocument获得该接口