wchar_t char string wstring 之间的转换

在处理中文时有时需要进行wchar_t，char，string，wstring之间的转换。

其中char和string之间、wchar_t和wstring之间的转换较为简单，代码在vs2010下测试通过。

#include <iostream>
#include <string>
#include <tchar.h>
#include <Windows.h>

using namespace std;

//Converting a WChar string to a Ansi string
char *w2c(char *pcstr,const wchar_t *pwstr, size_t len)
{
	int nlength=wcslen(pwstr);
	//获取转换后的长度
	int nbytes = WideCharToMultiByte( 0, 0, pwstr, nlength, NULL,0,NULL, NULL ); 
	if(nbytes>len)   nbytes=len;
	// 通过以上得到的结果，转换unicode 字符为ascii 字符
	WideCharToMultiByte( 0,0, pwstr, nlength,   pcstr, nbytes, NULL,   NULL );
	return pcstr ;
}

int main(){

	setlocale(LC_ALL,"chs");
	char* cc = "this is a char 测试";
	wchar_t* wcc = L"this is a wchar 测试";
	string str("this is a string 测试 ");
	wstring wstr = L"this is a wstring 测试";


	//string to char
	const char* char_test = str.c_str(); 
	//cout<<"char_test:"<<char_test<<endl;

	//char to string
	string ss = cc;
	//cout<<"ss is :"<<ss<<endl;

	//wstring to wchar
	const wchar_t* wchar_test = wstr.c_str(); 
	//wcout<<wchar_test<<endl;

	//wchar to wstring
	wstring wss = wcc;
	wcout<<wcc<<endl;

	//char to wchar_t
	wchar_t *wc = new wchar_t[str.size()+1];
	//swprintf(wc,L"%S",cc); 
	//wcout<<cc<<endl;
	delete []wc;
	
	// wchar_t to char
	char *pcstr = (char *)malloc(sizeof(char)*(2 * wcslen(wcc)+1));
	memset(pcstr , 0 , 2 * wcslen(wcc)+1 );
	w2c(pcstr,wcc,2 * wcslen(wcc)+1) ;
	free(pcstr);
	
	system("pause");
	return 1;
}