RegEx Tpis

1. IsEnglishLetter

4-26 16:07:29 PM IS2120@CSDN  
1. 正则表达式，匹配（字母，数字，子母和数字）  
Only letters:  
Regex.IsMatch(input, @"^[a-zA-Z]+$");  
  
Only letters and numbers:  
Regex.IsMatch(input, @"^[a-zA-Z0-9]+$");  
  
Only letters, numbers and underscore:  
Regex.IsMatch(input, @"^[a-zA-Z0-9_]+$");  
  
bool IsEnglishLetter(char c)  
{  
    return (c>='A' && c<='Z') || (c>='a' && c<='z');  
}  
  
You can make this an extension method:  
static bool IsEnglishLetter(this char c) ...  
  
You can use Char.IsLetter(c) && c < 128 . Or just c < 128 by itself, that seems to match   
your problem the closest.  
  
But you are solving an Encoding issue by filtering chars. Do investigate what that other   
application understands exactly.  
  
It could be that you should just be writing with Encoding.GetEncoding(someCodePage)  

2. c++ windows tr1 regex (vs 2008 sp 1 以上版本)

#include <regex>
#include <string>
#include <iostream>

//z 2014-05-19 13:07:42 L.226'39138 BG57IV3@XCL T1984143998.K.F253293061 [T467,L6323,R307,V7876]
// tr1 正则表达式 例子

/*
output: 2. Egg prices
*/
void Test_Search_Match()
{
	//std::tr1::cmatch res;
	std::tr1::match_results<const char*> res;
	std::string str = "<h2>Egg prices</h2>";
	std::tr1::regex rx("<h(.)>([^<]+)");    
	std::tr1::regex_search(str.c_str(), res, rx);    
	std::cout << res[1] << ". " << res[2] << "\n";
}

/*
output : Hello planet
*/
void Test_Replace_Match()
{
    std::string str = "Hello world";    
	std::tr1::regex rx("world");    
	std::string replacement = "planet";    
	std::string str2 = std::tr1::regex_replace(str, rx, replacement);

	std::cout << str2 <<std::endl;
}

int _tmain(int argc, _TCHAR* argv[])
{
	Test_Search_Match();
	std::cout << std::endl;
	Test_Replace_Match();

	return 0;
}