当在VC里编译时，发现这个警告，就是说设置的目录参数不是以反斜杠结束的目录名称，如下：
1>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140\Microsoft.CppBuild.targets(368,5): warning MSB8004: Output Directory does not end with a trailing slash. This build instance will add the slash as it is required to allow proper evaluation of the Output Directory.
按上图在$(ProjectDir)bin里改为$(ProjectDir)bin\，就可以了。