proe二次开发SOS

boboxiaoxun

我是个proe二次开发初学者，问个很菜的问题啊，
我按照张继春编的二次开发的书商步骤测试pro/toolkit时
将make_install改名为make_install.mak后，然后用vc打开，可是却出现
    this makefile was not generated by Developer Studio
    continuing will create a new Developer Studio project to wrap this makefile,you will be prompted to save after the new project has been create.
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为什么会这样？