C++ string best practices => LPTSTR, PSTR, CString, _T, TEXT, Win32 API, Win16. string, wstring.
strings
http://msdn.microsoft.com/en-us/library/ms174288.aspx
LPTSTR
http://baike.baidu.com/view/3186101.htm
Using CString very useful
http://msdn.microsoft.com/en-us/library/ms174288.aspx
CryptStringToBinary <=> CryptBinaryToString
// CString_example_1.cpp : Defines the entry point for the console application. // #include "stdafx.h" #include <stdio.h> #include <tchar.h> #include <windows.h> #include <string> #include <wincrypt.h> #include <iostream> // std::cout, std::end #pragma comment(lib, "crypt32.lib") int _tmain(int argc, _TCHAR* argv[]) { // Chinese characters for "zhongwen" ("Chinese language"). const BYTE kChineseSampleText[] = { -28, -72, -83, -26, -106, -121, 0 }; //-28 => 1110,0100 => 228 //-72 => 1011,1000 => 184 //-83 => 1010,1101 => 173 //-26 => 1110,0110 => 230 //-106 => 1001,0110 => 150 //-121 => 1000,0111 => 135 //const char kChineseSampleText[] = "xe4xb8xadxe6x96x87"; //const char kChineseSampleText[] = "e48ade69687"; DWORD strLen = 0; CryptBinaryToString(kChineseSampleText, 6, CRYPT_STRING_HEXRAW, NULL, &strLen ); LPTSTR string1 = new TCHAR[strLen + 1]; CryptBinaryToString(kChineseSampleText, 6, CRYPT_STRING_HEXRAW, string1, &strLen ); string1[strLen] = ' '; LPCTSTR stringC = string1; //string strii = wprintf(string1, "%s"); //string to bytes DWORD strCLen = 0; CryptStringToBinary( stringC, strLen, CRYPT_STRING_HEXRAW, NULL, &strCLen, 0, 0 ); BYTE* cwStr = new BYTE[strCLen + 1]; CryptStringToBinary( stringC, strLen, CRYPT_STRING_HEXRAW, cwStr, &strCLen, 0, 0 ); for (int i = 0; i < 6; i++) { BYTE x = cwStr[i]; x++; } return 0; }
Wstring -> bytes -> base64 -> bytes -> Wstring Example
// CString_example_1.cpp : Defines the entry point for the console application. // #include "stdafx.h" #include <stdio.h> #include <tchar.h> #include <windows.h> #include <string> #include <wincrypt.h> #include <iostream> // std::cout, std::end #pragma comment(lib, "crypt32.lib") void WstringToBytes(LPWSTR wszString, char* szAnsi, DWORD* bytesSize) { *bytesSize = WideCharToMultiByte(CP_UTF8, NULL, wszString, -1, NULL, 0, NULL, FALSE); WideCharToMultiByte(CP_UTF8, NULL, wszString, -1, szAnsi, *bytesSize, NULL, FALSE); } void BytesToWstring(char* bytes, LPWSTR wszString) { DWORD dwNum = MultiByteToWideChar(CP_UTF8, 0, bytes, -1, NULL, 0); MultiByteToWideChar(CP_UTF8, 0, bytes, -1, wszString, dwNum); //×îºó¼ÓÉÏ' ' wszString[dwNum] = ' '; } int _tmain(int argc, _TCHAR* argv[]) { // Chinese characters for "zhongwen" ("Chinese language"). //const BYTE kChineseSampleText[] = { -28, -72, -83, -26, -106, -121, 0 }; //-28 => 1110,0100 => 228 //-72 => 1011,1000 => 184 //-83 => 1010,1101 => 173 //-26 => 1110,0110 => 230 //-106 => 1001,0110 => 150 //-121 => 1000,0111 => 135 //const char kChineseSampleText[] = "xe4xb8xadxe6x96x87"; //const char kChineseSampleText[] = "e48ade69687"; LPWSTR plainText = L"abcd1234"; DWORD bytesLen = 6; char* buffer = new char[100]; WstringToBytes(plainText, buffer, &bytesLen); BYTE* kChineseSampleText = new BYTE[bytesLen + 1]; memcpy(kChineseSampleText, buffer, bytesLen); DWORD strLen = 0; CryptBinaryToString(kChineseSampleText, bytesLen, CRYPT_STRING_BASE64, //CRYPT_STRING_HEXRAW, CRYPT_STRING_BASE64 NULL, &strLen ); LPTSTR string1 = new TCHAR[strLen + 1]; CryptBinaryToString(kChineseSampleText, bytesLen, CRYPT_STRING_BASE64, //CRYPT_STRING_HEXRAW, CRYPT_STRING_BASE64 string1, &strLen ); string1[strLen] = ' '; LPCTSTR stringC = string1; //string strii = wprintf(string1, "%s"); //string to bytes DWORD strCLen = 0; CryptStringToBinary( stringC, strLen, CRYPT_STRING_BASE64, NULL, &strCLen, 0, 0 ); BYTE* cwStr = new BYTE[strCLen + 1]; CryptStringToBinary( stringC, strLen, CRYPT_STRING_BASE64, //CRYPT_STRING_HEXRAW, CRYPT_STRING_BASE64 cwStr, &strCLen, 0, 0 ); cwStr[strCLen] = ' '; /*for (int i = 0; i < 6; i++) { BYTE x = cwStr[i]; x++; }*/ LPWSTR result = (LPWSTR)malloc(1000); BytesToWstring((char*)cwStr, result); return 0; }
Example
UTF16 to UTF8 to UTF16 simple CString based conversion
http://www.codeproject.com/Articles/26134/UTF-to-UTF-to-UTF-simple-CString-based-conver
wstring => char*
char* = > wstring
int _tmain(int argc, _TCHAR* argv[]) { /*char sText[20] = { "多字节字符串!OK!" }; //bug; it is bytes DWORD dwNum = MultiByteToWideChar(CP_UTF8, 0, sText, -1, NULL, 0); wchar_t* pwText; pwText = new wchar_t[dwNum]; MultiByteToWideChar(CP_UTF8, 0, sText, -1, pwText, dwNum);*/ wchar_t wText[20] = { L"宽字符转换实例!OK!" }; DWORD dwNum2 = WideCharToMultiByte(CP_UTF8, NULL, wText, -1, NULL, 0, NULL, FALSE); char* psText; psText = new char[dwNum2]; WideCharToMultiByte(CP_UTF8, NULL, wText, -1, psText, dwNum2, NULL, FALSE); DWORD dwNum = MultiByteToWideChar(CP_UTF8, 0, psText, -1, NULL, 0); wchar_t* pwText; pwText = new wchar_t[dwNum]; MultiByteToWideChar(CP_UTF8, 0, psText, -1, pwText, dwNum); return 0; }
CString is an ATL/MFC class (actually, a specialization of the CStringT class template). Because ATL and MFC are Windows specific, the class is also inherently Windows specific. ATL and MFC are not included with VC++ Express, so if you don't have VC++ Professional or better, using this isn't an option for you.
If you want a string class that is platform agnostic, use std::string or std::wstring (which are specializations of the std::basic_string class template) instead, as these are part of the C++ standard library.
But, if you are going to write Win32 C++ code, I think CString's interface is more convenient (...but maybe someone would say it is more "bloated" ;)
For example: with CString you have methods to load strings from the resources.
Moreover, CString offers a convenient FormatMessage method, which is good for internationalization, see the so called problem of "Yoda speak" on Mihai Nita's blog post here:
http://mihai-nita.net/2006/04/15/string-api-and-internationalization/
And CString assumes that strings are NUL-terminated (which is good for interoperability with Win32 functions like say GetWindowText), instead std::[w]string doesn't.
And CString offers an implicit conversion operator LPCTSTR, so you can simply pass CString's to Win32 APIs having LPCTSTR parameters.
Moreover, if you are using a pre-VC10 compiler which does not support move semantics, I think storing CString in STL containers and passing them around is faster than std::[w]string, because CString uses COW (Copy-On-Write) technique, so it avoids useless copies (e.g. when a vector is resized because its capacity is insufficient). (However, I think this problem is solved in VC10 thanks to move semantics applied to std::[w]string.)