Under VC, Unicode and ANSI are converted to each other, cstringw and std:: string are converted to each other

Preface

as everyone knows ,CString There are two kinds of , They are using ANSI Coded CStringA And use Unicode Coded CStringW, among CStringA and std::string The transformation of is very simple , After all, they are used ANSI code , Let's not talk about it here , Only talk CStringW and std::string The transformation of .

Text

Microsoft has provided wide and narrow byte conversion API function , But it's a little troublesome , Here is Microsoft in ATL Several macros provided in , It's very easy to use . The following conversion macros are commonly used ：

1、W2A and A2W

2、CW2A and CA2W

One 、W2A and A2W How to use ：

#include <atlconv.h>
#include <atlstr.h>
int main(int argc, _TCHAR* argv[])
{
	// Use W2A and A2W when , This macro is required 
	USES_CONVERSION;
	CStringW strw = L"Hello World";
	//Unicode turn ANSI Use W2A
	std::string strstd = W2A(strw);
	//ANSI turn Unicode Use A2W
	strw = A2W(strstd.c_str());

	return 0;
}

Before using this set of macros, you need to use USES_CONVERSION macro , This set of macros was developed by Microsoft in its early days ATL3.0 Released in , Now it seems This set of macros has