SWMM源代码，里面包含SWMM计算引擎，以及动态链接库、源文件和头文件，可供其他软件进行二次开发(swmm resurce code reate a sub-directory named VC2010_DLL under the directory where
　 the SWMM 5 Engine source code files are stored and copy SWMM5.DEF
　 and VC2010-DLL.VCPROJ to it.)