Borland C++ Builder 6.0 XML处理总结

不念不忘少年蓝@ 2023-11-20 06:47 59阅读 0赞

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:  
view plaincopy to clipboardprint?  
//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：

view plaincopy to clipboardprint?  
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。

view plaincopy to clipboardprint?  
//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