使用fwrite()函数和fread()函数发生乱码问题

问题遇到的现象和发生背景

我做了一个基于哈希表的身份证查询系统，运行程序想把输入的信息写入文件中

void Save(IDLnode*& L)
{
    FILE* fp = fopen("D:\\IDcardSearchSystem.txt", "w");//打开文件
    if (fp == NULL)
    {
        perror("打开文件失败\n");
        system("pause");
        system("cls");
        return;
    }
    IDLnode* p = L;
    while (p != NULL)
    {
        fwrite(&p, sizeof(IDLnode),1, fp);
        p = p->next;
    }
    fclose(fp);    //关闭文件
    printf("保存成功！\n");
}
void Load(IDLnode*& L)
{
    FILE* fp = fopen("D:\\IDcardSearchSystem.txt", "r");//打开文件

    if (fp == NULL)
    {
        perror("\n打开文件失败.\n");
        return;
    }

    IDLnode p;
    while (fread(&p, sizeof(IDLnode),1, fp))
    {
        //创建新节点
        IDLnode* pNewNode = (IDLnode*)malloc(sizeof(IDLnode));

        pNewNode->next = NULL;

        //memcpy(pNewNode, &stu, sizeof(IDLnode));

        if (pNewNode != NULL)
        {
            strcpy(pNewNode->ID, p.ID);
            strcpy(pNewNode->Name, p.Name);
            strcpy(pNewNode->Address, p.Address);
            pNewNode->next = L;
            L = pNewNode;
        }

    }

    fclose(fp);

    printf("\n读取成功！\n");

    system("pause");
    system("cls");
}

遇到的现象和发生背景，请写出第一个错误信息

但是当我重新运行程序后，读取信息并将读取的信息打印在屏幕上发现是乱码，而非我之前填入的信息，这是为什么啊

用代码块功能插入代码，请勿粘贴截图。不用代码块回答率下降 50%

以下是部分代码

#define HashTableLength 50        //哈希表长度
#define IdLength 20        //身份证号长度
#define Prime 47    //质数
#define NameLength 30
#define AddressLength 50

//身份证单链表
typedef struct IDLnode
{
    char ID[IdLength];        //身份证号
    char Name[NameLength];            //姓名
    char Address[AddressLength];        //地址
    struct IDLnode* next;
}IDLnode;

//身份证号哈希表
typedef struct IDHashTable
{
    char HI_ID[IdLength];
    char HI_Name[NameLength];
    char HI_Address[AddressLength];
    int state;
}IDHashTable;

//姓名哈希表
typedef struct NameHashTable
{
    char HN_ID[IdLength];
    char HN_Name[NameLength];
    char HN_Address[AddressLength];
    int state;
}NameHashTable;
bool Insert(IDLnode*& L, IDHashTable*& IH, NameHashTable*& NH, const char* id, const char* name, const char* address)
{
    //头插添加进链表
    IDLnode* p = (IDLnode*)malloc(sizeof(IDLnode));
    if (p != NULL)
    {
        strcpy(p->ID, id);
        strcpy(p->Name, name);
        strcpy(p->Address, address);
        p->next = L;//->next;
        L = p;
    }
    const char temp[1] = { '\0' };
    //用哈希函数抽象出关键字放入哈希表中
    int namekey = HashName(name);        //获取关键字
    int idkey = HashID(id);
    //放入身份证号哈希表中
    while (IH[idkey].state == 1 && strcmp(IH[idkey].HI_ID, temp) != 0)    //线性探测再散列法，用state判断是否冲突，当state=1为冲突，向后存放关键字
        idkey++;
    strcpy(IH[idkey].HI_ID, id);
    strcpy(IH[idkey].HI_Name, name);
    strcpy(IH[idkey].HI_Address, address);
    IH[idkey].state = 1;
        
    //放入姓名哈希表中
    while (NH[namekey].state == 1 && strcmp(NH[namekey].HN_ID, temp) != 0)
        namekey++;
    strcpy(NH[namekey].HN_ID, id);
    strcpy(NH[namekey].HN_Name, name);
    strcpy(NH[namekey].HN_Address, address);
    NH[namekey].state = 1;

    return true;
}