实例简析XPath串函数和XSLT

2013 年 12 月 17 日3360

XPath(XML Path language)是一种处理XML文档段的语言。XSLT(Extensible Stylesheet Language Transformations,可扩展样式表语言转换)使用XPath描述表达式和地址路径控制节点选取。XSLT可以将XML转换为各种格式，如HTML或其他格式。
下面用一个邮件合并程序来简要说明XPath的串函数。下面的XML文件中包含数据，XSLT文件中包含对邮件格式的定义。MSXML4.0对XML文档应用样式表，产生一个合并的邮件文本文档。
XML文件 Letter.xml

July 17, 2002

Vicky
P
Male

900 National Pkwy
Suite 105
Bellevue
WA
98007
USA

ESTATE OF JOHN DOE / FILE NO. 12345.6789

Please pay the property taxes as soon as possible.

John
M
Sr. Tax Consultant

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XSLT样式表文档 Letter.xsl

xmlns:xsl="http://http://www.zjjv.com///1999/XSL/Transform">

To,

Regarding:

Dear Mr. Miss
,

Sincerely,

上面的样式表举例说明了concat和starts-with XPath串函数和怎样在输出文本中增加新行，还有定义和使用变量。
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下面是程序的执行结果。
1.VC6建立Win32控制台应用程序。
2.在stdafx.h中添加下面的代码：

#include
#include
#include
#import "msxml4.dll"
// If this import statement fails, you need to install MSXML 4.0 SP1 from:
//http://http://www.zjjv.com///downloads/sample.asp?url=/MSDN-FILES/027/001/766/msdncompositedoc.xml
#include
// If this include statement fails, you need to install MSXML 4.0 SP1 SDK from:
//http://http://www.zjjv.com///downloads/sample.asp?url=/MSDN-FILES/027/001/766/msdncompositedoc.xml
// You also need to add the include file and library search path
// to Visual C++'s list of directories (Tools > Options... > Directories).
using namespace MSXML2;
inline void EVAL_HR( HRESULT _hr )
{ if FAILED(_hr) throw(_hr); }
#define TEMP_SIZE _MAX_PATH // size of short buffer
static _TCHAR szTemp[TEMP_SIZE]; // multipurpose buffer on stack
static DWORD dwLen;

3.上面的代码引入MSXML4类型库，包含MSXML头文件，检查HRESULT值并声明了一些全局变量。
4.main函数：

int main(int argc, char* argv[])
{
try
{
EVAL_HR(CoInitialize(NULL));
// Make sure that MSXML 4.0 is installed
if (!isMSXMLInstalled())
return -1;
// Make sure that XML and XSL file names are passed
// as command line parameters
if (argc < 3)
// Show proper message here
return -1;

IXMLDOMDocument2Ptr pXMLDoc = NULL;
IXMLDOMDocument2Ptr pXSLDoc = NULL;

// Load the XML document
if (loadDocument(pXMLDoc, argv[1], true))
{
// Load the stylesheet
if (loadDocument(pXSLDoc, argv[2], false))
{
_ftprintf(stdout, pXMLDoc->transformNode(pXSLDoc));
}
else
{
printMSXMLError(pXSLDoc);
}
}
else
{
printMSXMLError(pXMLDoc);
}
}
catch(...)
{//exception handling
}