读文件到链表+界面管理

读文件到链表+界面管理

#include "stdafx.h"
#include <stdlib.h>


//数据类型
typedef struct student
{
	int num;
	char name[30];
	char sex;
	float math;
	float english;
	float chinese;
}Stu;


//链表类型
typedef struct node
{
	Stu data;
	struct node * next;
}Node;


//初始化并写入文件
void init()
{
	Stu stu[] = {
		{ 1001, "bob", 'x', 100, 30, 20 },
		{ 1002, "bob2", 'x', 100, 30, 20 },
		{ 1003, "bob3", 'x', 100, 30, 20 }
	};
	FILE* fp = fopen("stu.data", "wb+");
	if (NULL == fp)
		exit(-1);

	fwrite((void*)stu, sizeof(stu), 1, fp);
	fclose(fp);
}


//读文件生成链表
Node *createListFromFile()
{
	Node *head = (Node*)malloc(sizeof(Node));
	head->next = NULL;

	FILE* fp = fopen("stu.data", "rb");
	if (NULL == fp)
		exit(-1); //申请出错后 退出

	Node * cur = (Node*)malloc(sizeof(Node));
	//提前申请一个空间来装读取的数据 直接将数据放入链表中

	while (fread((void*)&cur->data, sizeof(Stu), 1, fp)>0)
	{
		cur->next = head->next;
		head->next = cur;
		cur = (Node*)malloc(sizeof(Node));
		//插入一个数据后重新申请一个空间 为下次读取准备
	}
	free(cur); //无论如何都会多申请一个空间 需要释放

	return head;
}


//打印链表中的所有信息
void displayListOfStu(Node *head)
{
	head = head->next;
	printf("\t\tnum \tname\t sex\tMath\tEng \tChi \n");

	while (head != NULL)
	{

		printf("\t\t%4d\t%5s\t%3c\t%4.2f\t%4.2f\t%4.2f\n",
			head->data.num, head->data.name, head->data.sex,
			head->data.math, head->data.english, head->data.chinese);

		head = head->next;
	}
}


//增加链表信息
void addListOfStu(Node *head)
{
	Node *node = (Node*)malloc(sizeof(Node));

	printf("请输入学号:"); scanf("%d", &node->data.num);
	printf("请输入姓名:"); scanf("%s", node->data.name); getchar();
	printf("请输入性别:"); scanf("%c", &node->data.sex);
	printf("请输入数学:"); scanf("%f", &node->data.math);
	printf("请输入英语:"); scanf("%f", &node->data.english);
	printf("请输入国文:"); scanf("%f", &node->data.chinese);

	node->next = head->next;
	head->next = node;
}


//将链表中数据保存到文件中
void saveList2File(Node *head)
{
	FILE*fp = fopen("stu.data", "wb");
	if (fp == NULL)
		exit(-1);

	head = head->next; //跳过没用的data数据

	while (head != NULL)
	{
		fwrite((void*)&head->data, sizeof(Stu), 1, fp);
		head = head->next;
	}
	fclose(fp);
}

//删除链表
void deleteListNodeOfStu(Node *head)
{

}

//查找链表
void searchListNodeOfStu(Node *head)
{

}



//菜单选择
void menu()
{
	Node *head = createListFromFile();  //开始时自动生成数据
	while (1) //一直等待输入操作
	{
		system("cls"); //刷屏
		printf("\t\t\t Student Management Sys\n\n");

		displayListOfStu(head); //打印已有数据

		printf("\n\t1->add Stu\t2->delete Stu\t3->Search Stu \t4->exit\n");

		int choice;
		scanf("%d", &choice); //选择功能 进行调用
		switch (choice) {
		case 1:
			addListOfStu(head);
			break;
		case 2:
			deleteListNodeOfStu(head);
			break;
		case 3:
			searchListNodeOfStu(head);
			break;
		case 4: //保存并退出
			saveList2File(head);
			exit(1);
			break;
		}
	}
}


int _tmain(int argc, _TCHAR* argv[])
{
	//init(); //运行整个程序之前 先init初始化生成相应文件
	menu();
	return 0;
}