时间：2019-03-17 标签：c++WriteFileunicodecharacters

Question

我正在尝试使用 WriteFile 函数将 wstring 写入 UTF-8 文件。\n我希望该文件具有这些字符“\xc3\x91\xc3\x81”，但我得到的是“\xef\xbf” \xbd"。

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这是代码

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#include <iostream>\n#include <cstdlib>\n#include <sstream>\n#include <string>\n#include <fstream>\n#include <windows.h>\n#include <wchar.h>\n#include <stdio.h>\n#include <winbase.h>\nusing namespace std;\n\nconst char filepath [] = "unicode.txt";\n\nint main ()\n{ \n   wstring str;\n   str.append(L"\xc3\x91\xc3\x81");\n   wchar_t* wfilepath;\n\n   // Create a file to work with Unicode and UTF-8\n   ofstream fs;\n   fs.open(filepath, ios::out|ios::binary);\n   unsigned char smarker[3];\n   smarker[0] = 0xEF;\n   smarker[1] = 0xBB;\n   smarker[2] = 0xBF;\n   fs << smarker;\n   fs.close();\n\n   //Open and write in the file with windows functions\n   mbstowcs(wfilepath, filepath, strlen(filepath));\n   HANDLE hfile;\n   hfile = CreateFileW(TEXT(wfilepath), GENERIC_WRITE, 0, NULL,\n       OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);\n   wstringbuf strBuf (str, ios_base::out|ios::app);\n   DWORD bytesWritten;\n   DWORD dwBytesToWrite = (DWORD) strBuf.in_avail();\n   WriteFile(hfile, &strBuf, dwBytesToWrite, &bytesWritten, NULL);\n   CloseHandle(hfile);\n}\n

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我使用以下命令行在 cygwin 上编译它：
\ng++ -std=c++11 -g Windows.C -o Windows

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Answer 1

在将 UTF-16 数据写入文件之前，您需要将其转换为 UTF-8。

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并且无需使用 创建文件std::ofstream、关闭它并使用 重新打开它CreateFileW()。只需打开文件一次并写入您需要的所有内容。

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尝试这个：

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#include <iostream>\n#include <cstdlib>\n#include <string>\n//#include <codecvt>\n//#include <locale>\n\n#include <windows.h>\n#include <wchar.h>\n#include <stdio.h>\n\nusing namespace std;\n\nLPCWSTR filepath = L"unicode.txt";\n\nstring to_utf8(const wstring &s)\n{\n    /*\n    wstring_convert<codecvt_utf8_utf16<wchar_t>> utf16conv;\n    return utf16conv.to_bytes(s);\n    */\n\n    string utf8;\n    int len = WideCharToMultiByte(CP_UTF8, 0, s.c_str(), s.length(), NULL, 0, NULL, NULL);\n    if (len > 0)\n    {\n        utf8.resize(len);\n        WideCharToMultiByte(CP_UTF8, 0, s.c_str(), s.length(), &utf8[0], len, NULL, NULL);\n    }\n    return utf8;\n}\n\nint main ()\n{ \n    wstring str = L"\xc3\x91\xc3\x81";\n\n    // Create a UTF-8 file and write in it using Windows functions\n    HANDLE hfile = CreateFileW(filepath, GENERIC_WRITE, 0, NULL,\n       CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);\n    if (hfile != INVALID_HANDLE_VALUE)\n    {\n        unsigned char smarker[3];\n        DWORD bytesWritten;\n\n        smarker[0] = 0xEF;\n        smarker[1] = 0xBB;\n        smarker[2] = 0xBF;\n        WriteFile(hfile, smarker, 3, &bytesWritten, NULL);\n\n        string strBuf = to_utf8(str);\n        WriteFile(hfile, strBuf.c_str(), strBuf.size(), &bytesWritten, NULL);\n\n        CloseHandle(hfile);\n    }\n\n    return 0;\n}\n

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