fstream中ios::mode汇总一览表

本文详细介绍了文件操作的各种模式,包括in(输入)、out(输出)、ate(从文件末尾开始)、binary(二进制模式)、app(从末尾开始追加)、trunc(清空已存在内容)。特别强调了binary模式的重要性,避免因模式错误导致的数据问题。

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主要是给自己做个笔记,方便查询。

 

标志位表示输入输出方式
成员常量全拼表示内容
ininput读文件
outoutput写文件
ateat the end从文件末尾开始
binarybinary以二进制模式打开,而不是txt模式,记住这个非常关键,如果模式不对读出来的数据可能出现很多意想不到的问题。
appappend写文件从末尾开始,如果不存在则创建文件
trunctruncate打开文件之前,清掉已存在的内容

备注:Trunc与app模式不能同时使用,Trunc需要与Out模式一起使用。

49725@DESKTOP-CB4LRLP /cygdrive/f/S $ g++ -o screensaver_clock F:/S/screensaver_clock.cpp -lgdiplus -mwindows F:/S/screensaver_clock.cpp: In function 'void SetFontSize(HWND)': F:/S/screensaver_clock.cpp:21:54: error: no matching function for call to 'std::basic_ofstream<wchar_t>::open(std::__cxx11::wstring&, const openmode&)' logFile.open(g_runtimeFilePath, std::ios::app); ^ In file included from F:/S/screensaver_clock.cpp:2: D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:851:7: note: candidate: 'void std::basic_ofstream<_CharT, _Traits>::open(const char*, std::ios_base::openmode) [with _CharT = wchar_t; _Traits = std::char_traits<wchar_t>; std::ios_base::openmode = std::_Ios_Openmode]' open(const char* __s, ios_base::openmode __mode = ios_base::out) ^~~~ D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:851:7: note: no known conversion for argument 1 from 'std::__cxx11::wstring' {aka 'std::__cxx11::basic_string<wchar_t>'} to 'const char*' D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:871:7: note: candidate: 'void std::basic_ofstream<_CharT, _Traits>::open(const string&, std::ios_base::openmode) [with _CharT = wchar_t; _Traits = std::char_traits<wchar_t>; std::__cxx11::string = std::__cxx11::basic_string<char>; std::ios_base::openmode = std::_Ios_Openmode]' open(const std::string& __s, ios_base::openmode __mode = ios_base::out) ^~~~ D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:871:7: note: no known conversion for argument 1 from 'std::__cxx11::wstring' {aka 'std::__cxx11::basic_string<wchar_t>'} to 'const string&' {aka 'const std::__cxx11::basic_string<char>&'} F:/S/screensaver_clock.cpp: In function 'void SetTitle(HWND)': F:/S/screensaver_clock.cpp:32:54: error: no matching function for call to 'std::basic_ofstream<wchar_t>::open(std::__cxx11::wstring&, const openmode&)' logFile.open(g_runtimeFilePath, std::ios::app); ^ In file included from F:/S/screensaver_clock.cpp:2: D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:851:7: note: candidate: 'void std::basic_ofstream<_CharT, _Traits>::open(const char*, std::ios_base::openmode) [with _CharT = wchar_t; _Traits = std::char_traits<wchar_t>; std::ios_base::openmode = std::_Ios_Openmode]' open(const char* __s, ios_base::openmode __mode = ios_base::out) ^~~~ D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:851:7: note: no known conversion for argument 1 from 'std::__cxx11::wstring' {aka 'std::__cxx11::basic_string<wchar_t>'} to 'const char*' D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:871:7: note: candidate: 'void std::basic_ofstream<_CharT, _Traits>::open(const string&, std::ios_base::openmode) [with _CharT = wchar_t; _Traits = std::char_traits<wchar_t>; std::__cxx11::string = std::__cxx11::basic_string<char>; std::ios_base::openmode = std::_Ios_Openmode]' open(const std::string& __s, ios_base::openmode __mode = ios_base::out) ^~~~ D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:871:7: note: no known conversion for argument 1 from 'std::__cxx11::wstring' {aka 'std::__cxx11::basic_string<wchar_t>'} to 'const string&' {aka 'const std::__cxx11::basic_string<char>&'} F:/S/screensaver_clock.cpp: In function 'void SetCountdownDate(HWND)': F:/S/screensaver_clock.cpp:43:54: error: no matching function for call to 'std::basic_ofstream<wchar_t>::open(std::__cxx11::wstring&, const openmode&)' logFile.open(g_runtimeFilePath, std::ios::app); ^ In file included from F:/S/screensaver_clock.cpp:2: D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:851:7: note: candidate: 'void std::basic_ofstream<_CharT, _Traits>::open(const char*, std::ios_base::openmode) [with _CharT = wchar_t; _Traits = std::char_traits<wchar_t>; std::ios_base::openmode = std::_Ios_Openmode]' open(const char* __s, ios_base::openmode __mode = ios_base::out) ^~~~ D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:851:7: note: no known conversion for argument 1 from 'std::__cxx11::wstring' {aka 'std::__cxx11::basic_string<wchar_t>'} to 'const char*' D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:871:7: note: candidate: 'void std::basic_ofstream<_CharT, _Traits>::open(const string&, std::ios_base::openmode) [with _CharT = wchar_t; _Traits = std::char_traits<wchar_t>; std::__cxx11::string = std::__cxx11::basic_string<char>; std::ios_base::openmode = std::_Ios_Openmode]' open(const std::string& __s, ios_base::openmode __mode = ios_base::out) ^~~~ D:/wingcc/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/fstream:871:7: note: no known conversion for argument 1 from 'std::__cxx11::wstring' {aka 'std::__cxx11::basic_string<wchar_t>'} to 'const string&' {aka 'const std::__cxx11::basic_string<char>&'}报错,优化代码,代码全输出
最新发布
05-13
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