utf,unicode,ascii字符串之间的相互转换

来源：互联网发布：石家庄知乎编辑：程序博客网时间：2024/06/08 01:03

作者：飘飘白云

utf8 转换到 utf16 ：

CStringW ConvertUTF8ToUTF16(const CStringA& utf8){int wLen = MultiByteToWideChar(CP_UTF8, 0, utf8, -1, 0, 0);CStringW buf;WCHAR*dd = buf.GetBuffer(wLen);wLen = MultiByteToWideChar(CP_UTF8, 0, utf8, -1, dd, wLen);buf.ReleaseBuffer(wLen);return buf;}

unicode 转换到 utf8 ：

CStringA ConvertUnicodeToUTF8(const CStringW& unicode){// wide char to multi charint wLen = WideCharToMultiByte(CP_UTF8, 0, unicode, -1, NULL, 0, NULL, NULL);CStringA buf;char* dd = buf.GetBuffer(wLen);WideCharToMultiByte(CP_UTF8, 0, unicode, -1, dd, wLen, NULL, NULL);buf.ReleaseBuffer(wLen);return buf;}

unicode 转换到 ascii ：

CStringA ConvertUnicodeToAnsi(const CStringW& unicode){// wide char to multi charint wLen = WideCharToMultiByte(CP_ACP, 0, unicode, -1, NULL, 0, NULL, NULL);CStringA buf;char* dd = buf.GetBuffer(wLen);WideCharToMultiByte(CP_ACP, 0, unicode, -1, dd, wLen, NULL, NULL);buf.ReleaseBuffer(wLen);return buf;}

另有一个 utf16 转换到 utf8 的非调用 WideCharToMultiByte 的版本：

int ConvertUnicodeToUTF8(const wchar_t* src, int srcLen, unsigned char* dest, int destLen){int i = 0;int outputlen = 0;/*bytes */char tchar;if (!src || !dest) {return outputlen;}for (i = 0; i < srcLen; i++) {if (outputlen >= destLen - 1) {//overflow detectedbreak;}// 0xxxxxxxif (src[i] < 0x80) {dest[outputlen++] = (unsigned char)(src[i]);}// 110xxxxx 10xxxxxxelse if (src[i] < 0x800) {dest[outputlen++] = (src[i] >> 6 | 0xc0);dest[outputlen++] = (src[i] & 0x3f | 0x80);}// 1110xxxx 10xxxxxx 10xxxxxxelse if (src[i] > 0xd800 && src[i] < 0xdfff) {tchar = (((src[i] & 0x3c0) >> 6) + 1);dest[outputlen++] = (tchar >> 2 | 0xf0);dest[outputlen++] = ((tchar & 0x03 | 0x80) | (src[i] & 0x3e) >> 2);}else {dest[outputlen++] = (src[i] >> 12 | 0xe0);dest[outputlen++] = (src[i] >> 6 & 0x3f | 0x80);dest[outputlen++] = (src[i] & 0x3f | 0x80);}}dest[outputlen] = '/0';return outputlen;}