Question

你能帮我弄清楚为什么我会收到这些2019年的错误吗？我很确定所有文件都保存在正确的位置，我想我正在使用头文件的正确约定？这是我的系统编程类的实验室。

以下是错误：

1＆gt; main.obj：错误LNK2019：未解析的外部符号“public：   __thiscall DLL :: intDLL :: intDLL（void）“（?? 0intDLL @ DLL @@ QAE @ XZ）在函数_main中引用

1＆gt; main.obj：错误LNK2019：未解析的外部符号“public：   __thiscall DLL :: intDLL :: ~intDLL（void）“（?? 1intDLL @ DLL @@ QAE @ XZ）在函数_main中引用

1＆gt; main.obj：错误LNK2019：未解析的外部符号“public：void   __thiscall DLL :: intDLL :: addFront（int）“（？addFront @ intDLL @ DLL @@ QAEXH @ Z）在函数_main中引用

1＆gt; main.obj：错误LNK2019：未解析的外部符号“public：int   __thiscall DLL :: intDLL :: getFront（void）“（？getFront @ intDLL @ DLL @@ QAEHXZ）在函数_main中引用

1＆gt; c：\ users \ josh \ documents \ visual studio   2012 \ Projects \ Lab10 \ Debug \ Lab10.exe：致命错误LNK1120：4   未解决的外部因素

intDLL.h文件：

#include <iostream>
using std::cout;
using std::endl;

class intDLL {

public:
    intDLL();
    intDLL(const intDLL &original);
    ~intDLL();
    void addFront(int inValue);
    void addBack(int inValue);
    void setBack();
    int getFront();
    int getBack();

    struct node {
        int value;
        node *next;
        node *prev;
    };

private:
    node *front;
    node *back;

};

intDLL.cpp

#include <iostream>
#include "intDLL.h"
using std::cout;
using std::endl;


intDLL::intDLL() {
    front = 0;
    back = 0;
}

void intDLL::setBack() {
    node *tempNode = new node;
    if(front == 0) {
        return;
    }

    tempNode = front;
    while(tempNode->back != 0) {
        tempNode = tempNode->prev;  
    }

    back = tempNode;
}

void intDLL::addFront(int inValue) {
    if(front == 0) {
        node *newFront = new node;
        newFront->value = inValue;
        newFront->next = 0;
        newFront->prev = 0;
    }
    else {
        node *newFront = new node;
        newFront->value = inValue;
        newFront->prev = front;
        front->next = newFront;
        newFront->next = 0;
        front = newFront;
    }

    setBack();
}

void intDLL::addBack(int inValue) {
    setBack();
    node *newBack = new node;
    newBack -> value = inValue;
    back->prev = newBack;
    newBack->next = back;
    back = newBack;
}

int intDLL::getFront() {
    return front->value;
}

int intDLL::getBack() {
    return back->value;
}

主：

#include <iostream>
#include "intDLL.h"
using std::cout;
using std::endl;

int main(int argc, char* argv[]) {
    intDLL test = intDLL();
    test.addFront(3);
    test.addFront(4);
    test.addFront(5);
    std::cout << test.getFront() << endl;

    return 0;
}

Answer 1

不确定真正的错误消息是什么，但似乎没有实现一些函数，样本

intDLL(const intDLL &original);
~intDLL();

检查函数定义以确保定义了声明的每个函数。还要确保编译和链接所有cpp文件。

另一个错误是intDLL::node没有后退成员

void intDLL::setBack() {
    intDLL::node *tempNode = new node;
     ^^^^ node is defined in intDLL, you need provide scope
    if(front == 0) {
       return;
    }

  tempNode = front;
  while(tempNode->back != 0) {
                  ^^^ intDLL::node has no back member
    tempNode = tempNode->prev;  
   }

  back = tempNode;
}

请参阅此SO链接。

LNK 2019/1120错误我的标题/源文件使用双链表进行练习

1 个答案: