C++ 多字节string转UTF-8 string

需求:数据库数据格式为UTF-8,本地VS工程编码字符集为多字节字符集,导入到本地csv文件时需要转化多字节std::string为UTF-8 std::string

接口与实现:

 1 #include <Windows.h>
 2 #include <string>
 3 
 4 //以下为main需要的头文件,接口实现不需要
 5 #include <iostream>
 6 #include <fstream>
 7 using namespace std;
 8 
 9 std::wstring MultiChartoWideChar(std::string str)
10 {
11     int nLen = MultiByteToWideChar(CP_ACP, 0, str.c_str(), (int)(str.size()), NULL, 0);
12     WCHAR *pBuffer = new WCHAR[nLen + 1];
13     MultiByteToWideChar(CP_ACP, 0, str.c_str(), (int)(str.size()), pBuffer, nLen);
14     pBuffer[nLen] = '\0';
15     std::wstring wstr;
16     wstr.append(pBuffer);
17     delete[] pBuffer;
18     return wstr;
19 }
20 
21 std::string WideChartoMultiChar(std::wstring wstr)
22 {
23     int nLen = WideCharToMultiByte(CP_UTF8, 0, wstr.c_str(), (int)(wstr.size()), NULL, 0, NULL, NULL);
24     CHAR *pBuffer = new CHAR[nLen + 1];
25     WideCharToMultiByte(CP_UTF8, 0, wstr.c_str(), (int)(wstr.size()), pBuffer, nLen, NULL, NULL);
26     pBuffer[nLen] = '\0';
27     std::string str;
28     str.append(pBuffer);
29     delete[] pBuffer;
30     return str;
31 }
32 
33 std::string stringToUTF8string(std::string str)
34 {
35     std::wstring wstr = MultiChartoWideChar(str);
36     return WideChartoMultiChar(wstr);
37 }
38 
39 int main()
40 {
41     std::string str = "C++字符串编码转换";
42     cout << "源字符串:" << str << endl;
43     cout << "UTF8字符串:"<< stringToUTF8string(str) << endl;
44 
45     ofstream ofs;
46     ofs.open("utf8.txt", ios::trunc);
47     ofs << stringToUTF8string(str) << endl;
48     ofs.close();
49 
50     system("Pause");
51     return 0;
52 }