有关错误可能来自哪里的任何想法？在构建解决方案时，我收到此构建失败消息。我有一个MyFolder程序文件夹，我复制并粘贴并命名为MyFolder2（现在有两个不同的文件夹，用于两个程序，MyFolder和MyFolder2）。我还做了一个查找/替换，用文件夹中的所有文件替换所有“MyFolder”和“MyFolder2”，并尽力确保区分大小写。 MyFolder编译得很好。 MyFolder2产生以下消息：
1>------ Build started: Project: MyFolder2, Configuration: Release x64 ------
1>Build started 2/15/2012 8:46:34 PM.
1>InitializeBuildStatus:
1> Touching "x64\Release\MyFolder2.unsuccessfulbuild".
1>ClCompile:
1> All outputs are up-to-date.
1> All outputs are up-to-date.
1> All outputs are up-to-date.
1>Link:
1> Creating library x64\Release\Homework_dlls\MyFolder2.lib and object x64
\Release\Homework_dlls\MyFolder2.exp
1>MyFolder.obj : error LNK2001: unresolved external symbol "public: static class
std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >
MyFolder2::m_HomeworkType" (?m_HomeworkType@MyFolder2@@2V?$basic_string@DU
?$char_traits@D@std@@V? $allocator@D@2@@std@@A)
1>x64\Release\Homework_dlls\MyFolder2.dll : fatal error LNK1120: 1 unresolved externals
1>
1>Build FAILED.
1>
1>Time Elapsed 00:00:01.09
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========