How to tell if a DLL is 32-bit or 64-bit

First make sure that visual studio has been installed, then search in the installation path, dumpbin.exe
enter the folder where dumpbin.exe is located, and open the terminal. (Directly enter cmd in the path box and press Enter)
and then enter the following command to query:

dumpbin.exe /headers [dll文件路径] | find "machine"

Example:

D:\VS2019\VC\Tools\MSVC\14.29.30133\bin\Hostx64\x86>dumpbin.exe /headers E:\zhankun\program_github\Ag_PlanAlgo\HnAlgorithm\include\HnAlgorithm3.dll |find "machine"

D:\VS2019\VC\Tools\MSVC\14.29.30133\bin\Hostx64\x86>dumpbin.exe /headers E:\zhankun\program_github\Ag_PlanAlgo\other_demo\GPV_pathplantool\HnAlgorithm3.dll |find "machine"

D:\VS2019\VC\Tools\MSVC\14.29.30133\bin\Hostx64\x86>dumpbin.exe /headers E:\zhankun\program_github\Ag_PlanAlgo\other_demo\GPV_pathplantool\HnAlgorithm2.dll |find "machine"
            8664 machine (x64)

D:\VS2019\VC\Tools\MSVC\14.29.30133\bin\Hostx64\x86>dumpbin.exe /headers E:\zhankun\program_github\Ag_PlanAlgo\other_demo\GPV_pathplantool\HnAlgorithm.dll |find "machine"
             14C machine (x86)
                   32 bit word machine