对话框数目比较多，我自己写了一个头文件foodlist.h，里面定义了两个类，那么在其他对话框用到这个类的时候就得在该文件添加#include"foodlist.h"。问题是在一个对话框文件中添加这一头文件不会出现问题，在多个对话框文件同时添加我写的这个头文件以后，程序就无法运行了。求教大神，下楼附上编译时的问题。

FoodDlg.obj : error LNK2005: "public: __thiscall CFood::CFood(void)" (??0CFood@@QAE@XZ) already defined in CustomerDlg.obj
FoodDlg.obj : error LNK2005: "public: __thiscall CFood::CFood(class CString,int,int,int,class CString)" (??0CFood@@QAE@VCString@@HHH0@Z) already defined in CustomerDlg.obj
FoodDlg.obj : error LNK2005: "public: __thiscall CFoodList::CFoodList(void)" (??0CFoodList@@QAE@XZ) already defined in CustomerDlg.obj
FoodDlg.obj : error LNK2005: "public: void __thiscall CFoodList::AddNode(class CString,int,int,int,class CString)" (?AddNode@CFoodList@@QAEXVCString@@HHH0@Z) already defined in CustomerDlg.obj
FoodDlg.obj : error LNK2005: "public: void __thiscall CFoodList::DeleteNode(class CFood *)" (?DeleteNode@CFoodList@@QAEXPAVCFood@@@Z) already defined in CustomerDlg.obj
FoodDlg.obj : error LNK2005: "public: void __thiscall CFoodList::ChangeState(class CFood *)" (?ChangeState@CFoodList@@QAEXPAVCFood@@@Z) already defined in CustomerDlg.obj
FoodDlg.obj : error LNK2005: "public: void __thiscall CFoodList::ChangeNode(class CFood *,class CString,int)" (?ChangeNode@CFoodList@@QAEXPAVCFood@@VCString@@H@Z) already defined in CustomerDlg.obj
FoodDlg.obj : error LNK2005: "public: class CFood * __thiscall CFoodList::FindNode(class CString)" (?FindNode@CFoodList@@QAEPAVCFood@@VCString@@@Z) already defined in CustomerDlg.obj
FoodDlg.obj : error LNK2005: "public: void __thiscall CFoodList::LoadFromFile(char *)" (?LoadFromFile@CFoodList@@QAEXPAD@Z) already defined in CustomerDlg.obj
FoodDlg.obj : error LNK2005: "public: void __thiscall CFoodList::ReleaseList(void)" (?ReleaseList@CFoodList@@QAEXXZ) already defined in CustomerDlg.obj
FoodDlg.obj : error LNK2005: "public: void __thiscall CFoodList::SaveToFile(char *)" (?SaveToFile@CFoodList@@QAEXPAD@Z) already defined in CustomerDlg.obj
FoodDlg.obj : error LNK2005: "class CFoodList m_List" (?m_List@@3VCFoodList@@A) already defined in CustomerDlg.obj
Debug/外卖哦.exe : fatal error LNK1169: one or more multiply defined symbols found

显示就一个错误，但是这么长，而且我试了很多次，原因似乎就是我把自己编写的头文件添加到多个对话框文件造成的，真的不会解决了，大家教教我吧。

对了，我感觉是不是我类成员函数也放在了头文件的缘故啊？

already defined in CustomerDlg.obj
是不是重复定义了？你在你的头文件最前面加上#pragma once