VS2010 Package DLL times wrong: Error LNK2019: unresolved external symbols "__declspec (dllimport) _visual

VS2010 Package DLL times wrong:

Error LNK2019: unresolved external symbol "__declspec (dllimport) const ctriplinedetection:: ' vftable '" (__imp_?? _7ctriplinedetection@@6b@), the symbol is in the function "public: __thiscall ctriplinedetection::ctriplinedetection (void)" (?? 0ctriplinedetection@ @QAE @xz) is referenced 1>m:\test\svnnew4.2\allneeds\triplinedetection.dll:fatal error lnk1120:1 An unresolved external command

Online search solutions, some netizens suggest:

An engineering build DLL file is executed for another project, but error LNK2019: an unresolved external symbol "__declspec (dllimport) error occurs at each execution. Check the code several times and feel that there is no problem.

Finally, the character set was found to be problematic. The character set of the build DLL file is Unicode and the character set for the EXE file is the default ASCII.

The problem can be resolved as long as the unified character set:

The VS2005 C + + Project default character set is the use of the Unicode character set, which sets the character set in the project properties-> Configuration Properties--> The General-> project default-> character set.

The supplemental VC6.0 is by default in the ASCII character set.

But I found that the default character set in engineering is the use of the Unicode character set, this method can not solve the problem, the program will still complain

The solution is:

Suppose the newly defined DLL name is Newfuncdll

Property-> Configuration properties are added->c/c++-> preprocessor-> preprocessor definitions; Newfuncdll problem can be solved