未定义引用 Class::Function 链接器错误

Question

尝试从两个 .cpp 文件和一个 .h 文件构建可执行文件，但似乎出现链接器错误。这是我遇到的错误...

/usr/bin/ld: CMakeFiles/Diary.dir/home/adam/Dev/Diary/src/Main.cpp.o:
in function `main': Main.cpp:(.text+0x73): undefined reference to
`Entry::write(char*, char*)' collect2: error: ld returned 1 exit
status make[2]: *** [CMakeFiles/Diary.dir/build.make:85:
/home/adam/Dev/Diary/bin/Diary] Error 1 make[1]: ***
[CMakeFiles/Makefile2:105: CMakeFiles/Diary.dir/all] Error 2 make: ***
[Makefile:84: all] Error 2

这是我的代码...

Main.cpp

#include <iostream>
#include "CSV.hpp"

using namespace std;

int main(int argc, char* argv[]) {
    
    if(argc==1){
        cout << "Usage: ./Diary add <date> <text>" << endl;
    }
    else{
        Entry entry;
        bool success = entry.write(argv[1], argv[2]);
    }

    return 0;
}

CSV.cpp

#include <iostream>
#include <fstream>

using namespace std;

class Entry {
    private:
    public:
    bool write (char* date, char* text){
        ofstream file;
        file.open("../Diary.csv", ios_base::app);
        file << date << "," << text << endl;
        file.close();
        return true;
    }

};

CSV.hpp

#pragma once

class Entry{
    private:
    public:
    bool write (char* date, char* text);
};

真的不确定问题出在哪里。有什么建议吗？

Answer 1

您 CSV.cpp 文件应该是这样的：

#include <iostream>
#include <fstream>

#include "CSV.hpp"

using namespace std;

bool Entry::write (char* date, char* text)
{
    ofstream file;
    file.open("../Diary.csv", ios_base::app);
    file << date << "," << text << endl;
    file.close();
    return true;
}

并且您必须将 cpp 文件（Main.cpp 和 CSV.cpp）和 link 编译为 target（您的程序可执行文件。）

未定义引用 Class::Function 链接器错误

Undefined reference to Class::Function linker error

c++

linker

linker-errors