未定义的引用`Class :: Class()'

Question

我正在写一个GTKmm窗口程序; 主窗口创建两个按钮,一个用于英语,一个用于中文.用户可以单击按钮以适当的语言显示不同的窗口.目前我在主窗口内初始化多项容器时遇到问题.它是MainWindowPane类型的对象,它继承了Gtk :: HBox.

当我尝试制作时,编译器发出以下错误:

$ make 
g++ -g `pkg-config gtkmm-2.4 --cflags` -c MainWindow.cpp  
g++  -g -o QPI_frontend main.o MainWindow.o StartButton.o `pkg-config gtkmm-2.4 --libs`  
MainWindow.o: In function `MainWindow':  
/home/dmurvihill/Documents/QPI_frontend/MainWindow.cpp:9: undefined reference to   `MainWindowPane::MainWindowPane()'  
/home/dmurvihill/Documents/QPI_frontend/MainWindow.cpp:9: undefined reference to  `MainWindowPane::MainWindowPane()'  
collect2: ld returned 1 exit status  
make: *** [QPI_frontend] Error 1  

我正在使用最新版本的gcc和pkg-config来包含适当的库.我也是一个java人.

/*
 * MAIN_WINDOW.H
 * Responsible for creating "slave" RSED windows. Can create English or Chinese
 * versions of the demo, and can destroy them all with one click.
 */  
#ifndef MAINWINDOW_H  
#define MAINWINDOW_H  

#include <gtkmm/window.h>

//#include "SlaveWindow.h"
#include "StartButton.h"
#include "MainWindowPane.h"

class MainWindow : public Gtk::Window
{
public:
    MainWindow();   
private:
    MainWindowPane pane;
//  std::list<SlaveWindowThread> windows;       // Keeps track of all windows that have been created thus far.
    void destroyAllWindows();           // Iterates through the linked list and destroys each window.
};
#endif      //ifndef MAINWINDOW_H

---

/* 
 * MAIN_WINDOW.CPP
 *
 */  
#include "MainWindow.h"  
#include "MainWindowPane.h"  
#include "StartButton.h"  

MainWindow::MainWindow()// : /*list,*/ pane(/*list*/)
{
    pane;
}

void MainWindow::destroyAllWindows()
{
    //gtk_widget_destroy(*this);
    // TODO: Destroy all the other windows too.
}

---

/*
 * MAIN_WINDOW_PANE.H
 */  
#ifndef MAINWINDOWPANE_H  
#define MAINWINDOWPANE_H  

#include <gtkmm/box.h>
#include <gtkmm/button.h>

//#include "SlaveWindow.h"
#include "StartButton.h"

class MainWindowPane : public Gtk::HBox
{
public:
    MainWindowPane(/*&(std::list)*/);   
private:
    StartButton englishButton;      // Used to create a new RSED demo screen.
    StartButton chineseButton;      // Used to create a new RSED demo in chinese.
//  std::list<SlaveWindow> windows;     // Keeps track of all windows that have been created thus far.
    void destroyAllWindows();       // Iterates through the linked list and destroys each window.
};
#endif      //ifndef MAINWINDOWPANE_H

---

/* 
 * MAIN_WINDOW.CPP
 *
 */  
#include "MainWindowPane.h"  
#include "StartButton.h"  

MainWindowPane::MainWindowPane(/*&(std::list)*/) : 
    englishButton(StartButton::ENGLISH/*,&(std::list)*/), 
    chineseButton(StartButton::CHINESE/*,&(std::list)*/)
{
    pack_start(englishButton);
    englishButton.show();
    pack_start(chineseButton);
    chineseButton.show();
}

void MainWindow::destroyAllWindows()
{
    //gtk_widget_destroy(*this);
    // TODO: Destroy all the other windows too.
}

Answer 1

未定义的引用错误意味着您要么忘记编写定义缺失的函数(通过在.cpp文件中编写实现),要么忘记将相应的对象文件或库链接到最终的二进制文件中.

在这种情况下,这是后来的原因.您需要MainWindowPane.o在makefile中的linker命令中包含:

g++  -g -o QPI_frontend main.o MainWindow.o StartButton.o `pkg-config gtkmm-2.4 --libs`
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                        you need MainWindowPane.o in here