VS 2022 C++ 自定义头文件示例

前言：

博主最近刚从VS Code转到VS 2022，但发现自定义的方法和VS Code有些不同，故出一期VS 2022自定义头文件的博客，时间仓促，请不吝赐教

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正文：

参考资料：Microsoft C++、C 和汇编程序文档

以"lnode.h"为例，您需要保证在头文件和源文件内均创建名为"lnode"的头文件和源文件；

lnode.h示例：

#pragma once
#include <iostream>
#include <vector>

const int MaxSize = 1e3 + 10;
typedef int ElemType;

typedef struct LNode
{
    ElemType data;
    struct LNode* next;
} LNode;

void CreateLNodeRear(LNode*& L, ElemType a[], int n);
void InitLNode(LNode*& L);
void DestroyLNode(LNode*& L);
bool IfEmpty(LNode* L);
int LNodeLen(LNode* L);
void DisplayLNode(LNode* L);
bool GetElem(LNode* L, int i, ElemType& e);
int LocateElem(LNode* L, ElemType e);
bool InsertLNode(LNode*& L, int i, ElemType e);
bool DeleteLNode(LNode*& L, int i, ElemType& e);

显然，函数的声明，类的定义，结构体的定义都写在头文件内；

注意，using namespace std 最好不要写在头文件内。

推荐阅读：[C++] 头文件中不要用using namespace std

lnode.cpp示例：

#include <iostream>
#include <vector>
#include"lnode.h"

using namespace std;
void CreateLNodeRear(LNode*& L, ElemType a[], int n)
{
    LNode* s, * rear;
    L = (LNode*)malloc(sizeof(LNode));
    rear = L;
    for (int i = 0; i < n; i++)
    {
        s = (LNode*)malloc(sizeof(LNode));
        s->data = a[i];
        rear->next = s;
        rear = s;
    }
    rear->next = NULL;
}

void InitLNode(LNode*& L)
{
    L = (LNode*)malloc(sizeof(LNode));
    L->next = NULL;
}

void DestroyLNode(LNode*& L)
{
    LNode* pre = L, * p = L->next;
    while (p != NULL)
    {
        free(pre);
        pre = p;
        p = pre->next;
    }
    free(pre);
}

bool IfEmpty(LNode* L)
{
    return (L->next == NULL);
}

int LNodeLen(LNode* L)
{
    LNode* p = L->next;
    int cnt = 0;
    while (p != NULL)
    {
        cnt++;
        p = p->next;
    }
    return cnt;
}

void DisplayLNode(LNode* L)
{
    LNode* p = L->next;
    while (p != NULL)
    {
        cout << p->data << " ";
        p = p->next;
    }
    cout << endl;
}

bool GetElem(LNode* L, int i, ElemType& e)
{
    LNode* s = L; // s指向头结点，j置0；
    int j = 0;

    if (i <= 0)
        return false;
    while (j < i && s != NULL)
    {
        j++;
        s = s->next;
    }
    if (s == NULL)
        return false;
    else
    {
        e = s->data;
        return true;
    }
}

int LocateElem(LNode* L, ElemType e)
{
    LNode* s = L->next;
    int j = 1; //数据结点指向首结点，j置为1（表明此时位置指向1）
    while (s != NULL && s->data != e)
    {
        s = s->next;
        j++;
    }
    if (s == NULL)
        return (0);
    else
    {
        return (j);
    }
}

bool InsertLNode(LNode*& L, int i, ElemType e)
{
    LNode* p = L, * s;
    int j = 0;

    if (i <= 0)
        return false;

    while (j < i - 1 && p != NULL)
    {
        j++;
        p = p->next;
    }

    if (p == NULL)
        return false;
    else
    {
        s = (LNode*)malloc(sizeof(LNode));
        s->data = e;
        s->next = p->next;
        p->next = s;
        return true;
    }
}

bool DeleteLNode(LNode*& L, int i, ElemType& e)
{
    LNode* p = L, * q;
    int j = 0;
    if (i <= 0)
        return false;
    while (j < i - 1 && p != NULL)
    {
        j++;
        p = p->next;
    }
    if (p == NULL)
        return false;
    else
    {
        q = p->next;
        if (q == NULL)
            return false;
        e = q->data;
        p->next = p->next->next;
        free(q);
        return true;
    }
}

显然，lnode.cpp内仅包含函数的实现过程，using namespace std 和头文件；

注意，lnode.cpp内一定要包含：

#include"lnode.h"

main.cpp示例： 

#include<iostream>
#include<vector>
#include"lnode.h"

using namespace std;

int main()
{
    LNode* L = nullptr;
h1:
    cout << "1.CreateLNodeRear;2.InitLNode;3.DestroyLNode;4.IfEmpty;5.DisplayLNode;" << endl;
    cout << "6.GetElem;7.LocateElem;8.InsertLNode;9.DeleteLNode;10.LNodeLen" << endl;

    int flag = 0;
    cin >> flag;

    if (flag == 1)
    {
        ElemType num;
        vector<ElemType> array;
        cout << "请输入待输入数组array,空格间隔，回车结束" << endl;
        while (1)
        {
            cin >> num;
            array.push_back(num);
            if (cin.get() == '\n')
                break;
        }
        int len = array.size();
        int a[MaxSize];
        for (int i = 0; i < len; i++)
            a[i] = array[i];
        CreateLNodeRear(L, a, len);
    }
    else if (flag == 2)
    {
        InitLNode(L);
    }
    else if (flag == 3)
    {
        DestroyLNode(L);
    }
    else if (flag == 4)
    {
        if (IfEmpty(L))
            cout << "Empty" << endl;
        else
            cout << "Not Empty" << endl;
    }
    else if (flag == 5)
    {
        DisplayLNode(L);
    }
    else if (flag == 6)
    {
        int i = 0, e = 0;
        cout << "请输入i的值" << endl;
        cin >> i;
        if (GetElem(L, i, e))
            cout << e << endl;
        else
            cout << "error!" << endl;
    }
    else if (flag == 7)
    {
        int e;
        cout << "请输入待查找的e" << endl;
        cin >> e;
        if (LocateElem(L, e) == 0)
            cout << "error!" << endl;
        else
            cout << LocateElem(L, e) << endl;
    }
    else if (flag == 8)
    {
        int i = 0, e = 0;
        cout << "请输入i的值" << endl;
        cin >> i;
        cout << "请输入e的值" << endl;
        cin >> e;
        InsertLNode(L, i, e);
    }
    else if (flag == 9)
    {
        int i = 0, e = 0;
        cout << "请输入i的值" << endl;
        cin >> i;
        if (!DeleteLNode(L, i, e))
            cout << "error!" << endl;
        else
            cout << "Finished." << endl;
    }
    else if (flag == 10)
    {
        cout << LNodeLen(L) << endl;
    }
    else
    {
        cout << "未识别指令" << endl;
    }

    cout << "是否继续?Y/N" << endl;
    char c;
    cin >> c;
    if (c == 'Y')
        goto h1;
    else
        return 0;
}

显然，main.cpp内亦要包含：

#include"lnode.h"

可以把”lnode.h“想成从main.cpp函数中提取的一部分，而将lnode.cpp想象成函数的实现部分。