#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <string.h>

typedef struct patient
{
    char id[20];
    char name[20];
    char sex[5];
    int age,year,month,day;
    char cases[200];
    char consumption[20];
    struct patient *next;
}PATIENT;

PATIENT * Input_Patient();
void Save_Patient(PATIENT *head);
void Find_Patient();


int main()
{
    PATIENT *h;
    h=Input_Patient();
    Find_Patient();
    return 0;
}

PATIENT * Input_Patient()
{
    PATIENT *p1,*p2,*head;
    int flag=1,x;

    head=(PATIENT *)malloc(sizeof(PATIENT));
    p1=head;
    while(flag==1)
    {
        p2=(PATIENT *)malloc(sizeof(PATIENT));
        printf("请输入病人ID:");
        scanf("%s",p1->id);
        printf("请输入病人姓名:");
        scanf("%s",p1->name);
        printf("请输入病人性别:");
        scanf("%s",p1->sex);
        printf("请输入病人年龄:");
        scanf("%d",&p1->age);
        printf("请输入病人入院时间(年/月/日):");
        scanf("%d%d%d",&p1->year,&p1->month,&p1->day);
        printf("请输入病人病例:");
        scanf("%s",p1->cases);
        printf("请输入病人消费情况:");
        scanf("%s",p1->consumption);
        p1->next=p2;
        p1=p2;
        printf("继续输入病人信息请按 1：");
        scanf("%d",&flag);
    }
    p2->next=NULL;
    printf("病人信息输入结束!\n是否保存病人信息？(1.是/2.否)\n");
    scanf("%d",&x);
    if(x==1)
        Save_Patient(head);
    ///else
        ///Main_Patient();
    return head;
}
void Save_Patient(PATIENT *head)
{
    PATIENT *p;
    FILE *fp;
    if((fp=fopen("patient","a"))==NULL)
    {
        printf("打开文件过程出现错误！\n");
        ///Main_Patient();
    }
    for(p=head->next;p!=NULL;p=p->next)
        fwrite(p,sizeof(PATIENT),1,fp);
    fclose(fp);
    printf("病人信息已存入！\n");
}
void Find_Patient()
{
    PATIENT *p;
    FILE *fp;
    int x;
    char id[20],name[20];

    p=(PATIENT *)malloc(sizeof(PATIENT));

    printf("请选择你要使用的查找方式：\n");
    printf("1.通过ID查找\n");
    printf("2.通过姓名查找\n");
    scanf("%d",&x);
    if(x==1)
    {
        printf("\n请输入病人ID：");
        scanf("%s",id);
        if((fp=fopen("patient","r"))==NULL)
        {
            printf("打开文件过程中出现错误！\n");
            exit(0);
        }
        while(!feof(fp))
        {
            fread(p,sizeof(PATIENT),1,fp);
            if(strcmp(p->name,name)==0)
            {
                printf("ID:%s\n姓名:%s\n性别:%s\n年龄:%d\n",p->id,p->name,p->sex,p->age);
                printf("入院时间：%02d/%02d/%02d\n病例：%s\n消费情况：%s\n",p->year,p->month,p->day,p->cases,p->consumption);
            }
        }
        fclose(fp);
    }
    else if(x==2)
    {
        printf("\n请输入病人姓名：");
        scanf("%s",name);
        if((fp=fopen("patient","r"))==NULL)
        {
            printf("打开文件过程中出现错误！\n");
            exit(0);
        }
        while(!feof(fp))
        {
            fread(p,sizeof(PATIENT),1,fp);
            if(strcmp(p->name,name)==0)
            {
                printf("ID:%s\n姓名:%s\n性别:%s\n年龄:%d\n",p->id,p->name,p->sex,p->age);
                printf("入院时间：%02d/%02d/%02d\n病例：%s\n消费情况：%s\n",p->year,p->month,p->day,p->cases,p->consumption);
            }
        }
        fclose(fp);
    }
}

[此贴子已经被作者于2018-3-12 20:55编辑过]

试试 fopen("patient","rb")

之前我也遇到过这种问题，不过我是用的VS，我不知道你是用的什么编译软件，可能和你文件打开或者读取的函数有关，你可以用楼上的试试

谢谢，但是还是不对

不好说，没看到将数据写到文件的代码。
Save_Patient()好象也没写文件的代码。

先给你指一下语法错误。再谈逻辑问题。

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <string.h>

typedef struct patient
{
    char id[20];
    char name[20];
    char sex[5];
    int age,year,month,day;
    char cases[200];
    char consumption[20];
    struct ptient *next; //结构体名称上面是写着patient对吧。
}PATIENT;

PATIENT * Input_Patient();
void Save_Patient(PATIENT *head);
void Find_Patient();


int main()
{
    PATIENT *h;
    h=Input_Patient();
    Find_Patient();
    return 0;
}

PATIENT * Input_Patient()
{
    PATIENT *p1,*p2,*head;
    int flag=1,x;

    head=(PATIENT *)malloc(sizeof(PATIENT));
    p1=head;
    while(flag==1)
    {
        p2=(PATIENT *)malloc(sizeof(PATIENT));
        printf("请输入病人ID:");
        scanf("%s",p1->id);
        printf("请输入病人姓名:");
        scanf("%s",p1->name);
        printf("请输入病人性别:");
        scanf("%s",p1->sex);
        printf("请输入病人年龄:");
        scanf("%d",&p1->age);
        printf("请输入病人入院时间(年/月/日):");
        scanf("%d%d%d",&p1->year,&p1->month,&p1->day);
        printf("请输入病人病例:");
        scanf("%s",p1->cases);
        printf("请输入病人消费情况:");
        scanf("%s",p1->consumption);
        p1->next=p2;
        p1=p2;
        printf("继续输入病人信息请按 1：");
        scanf("%d",&flag);
    }
    p2->next=NULL;
    printf("病人信息输入结束!\n是否保存病人信息？(1.是/2.否)\n");
    scanf("%d",&x);
    if(x==1)
        Save_Patient(head);
    ///else
        ///Main_Patient();
    return head;
}
void Save_Patient(PATIENT *head)
{
    PATIENT *p;
    FILE *fp;
    if((fp=fopen("patient","a"))==NULL)
    {
        printf("打开文件过程出现错误！\n");
        ///Main_Patient();
    }
    for(p=head->next;p!=NULL;p=p->next)
        fread(p,sizeof(PATIENT),1,fp);//下面的Find_Patient()是读取数据用fread可以理解。这里用fread是想要干啥？
    fclose(fp);
    printf("病人信息已存入！\n");
}


还有Find_Patient()函数，文件打开了，操作后又没fclose操作.

[此贴子已经被作者于2018-3-12 18:05编辑过]

啊应该是fwrite，改的次数有点多都改乱了。。

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <string.h>

typedef struct patient
{
    char id[20];
    char name[20];
    char sex[5];
    int age,year,month,day;
    char cases[200];
    char consumption[20];
    struct patient *next;
}PATIENT;

PATIENT * Input_Patient();
void Save_Patient(PATIENT *head);
void Find_Patient();


int main()
{
    PATIENT *h;
    h=Input_Patient();
    Find_Patient();
    return 0;
}

PATIENT * Input_Patient()
{
    PATIENT *p1,*p2,*head;
    int flag=1,x;

    head=(PATIENT *)malloc(sizeof(PATIENT));
    p1=head;
    while(flag==1)
    {
        p2=(PATIENT *)malloc(sizeof(PATIENT));//给p2申请了内存空间
        printf("请输入病人ID:");
        scanf("%s",p1->id);//这里的操作是直接给p1的成员录入数据，下面全是。。。
        printf("请输入病人姓名:");
        scanf("%s",p1->name);
        printf("请输入病人性别:");
        scanf("%s",p1->sex);
        printf("请输入病人年龄:");
        scanf("%d",&p1->age);
        printf("请输入病人入院时间(年/月/日):");
        scanf("%d%d%d",&p1->year,&p1->month,&p1->day);
        printf("请输入病人病例:");
        scanf("%s",p1->cases);
        printf("请输入病人消费情况:");
        scanf("%s",p1->consumption);
        p1->next=p2;//那么你这是想干啥??
        p1=p2;
        printf("继续输入病人信息请按 1：");
        scanf("%d",&flag);
    }
    p2->next=NULL;
    printf("病人信息输入结束!\n是否保存病人信息？(1.是/2.否)\n");
    scanf("%d",&x);
    if(x==1)
        Save_Patient(head);
    ///else
        ///Main_Patient();
    return head;
}
void Save_Patient(PATIENT *head)
{
    PATIENT *p;
    FILE *fp;
    if((fp=fopen("patient","a"))==NULL)
    {
        printf("打开文件过程出现错误！\n");
        ///Main_Patient();
    }
    for(p=head->next;p!=NULL;p=p->next)
        fwrite(p,sizeof(PATIENT),1,fp);
    fclose(fp);
    printf("病人信息已存入！\n");
}
void Find_Patient()
{
    PATIENT *p;
    FILE *fp;
    int x;
    char id[20],name[20];

    p=(PATIENT *)malloc(sizeof(PATIENT));

    printf("请选择你要使用的查找方式：\n");
    printf("1.通过ID查找\n");
    printf("2.通过姓名查找\n");
    scanf("%d",&x);
    if(x==1)
    {
        printf("\n请输入病人ID：");
        scanf("%s",id);
        if((fp=fopen("patient","r"))==NULL)
        {
            printf("打开文件过程中出现错误！\n");
            exit(0);
        }
        while(!feof(fp))
        {
            fread(p,sizeof(PATIENT),1,fp);
            if(strcmp(p->name,name)==0)//上面都写着id查询。输入id永远都查不到。
            {
                printf("ID:%s\n姓名:%s\n性别:%s\n年龄:%d\n",p->id,p->name,p->sex,p->age);
                printf("入院时间：%02d/%02d/%02d\n病例：%s\n消费情况：%s\n",p->year,p->month,p->day,p->cases,p->consumption);
              
            }//你这样写。这条循环，会打印两次或以上。
        }
        fclose(fp);
    }
    else if(x==2)
    {
        printf("\n请输入病人姓名：");
        scanf("%s",name);
        if((fp=fopen("patient","r"))==NULL)
        {
            printf("打开文件过程中出现错误！\n");
            exit(0);
        }
        while(!feof(fp))
        {
            fread(p,sizeof(PATIENT),1,fp);
            if(strcmp(p->name,name)==0)
            {
                printf("ID:%s\n姓名:%s\n性别:%s\n年龄:%d\n",p->id,p->name,p->sex,p->age);
                printf("入院时间：%02d/%02d/%02d\n病例：%s\n消费情况：%s\n",p->year,p->month,p->day,p->cases,p->consumption);
            }//同上
        }
        fclose(fp);
    }
}

稍微修改了一下。其它还有什么问题，你自己调试一下。

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <string.h>

typedef struct patient
{
    char id[20];
    char name[20];
    char sex[5];
    int age, year, month, day;
    char cases[200];
    char consumption[20];
    struct patient *next;
}PATIENT;

PATIENT * Input_Patient();
void Save_Patient(PATIENT *head);
void Find_Patient();


int main()
{
    PATIENT *h;
    h = Input_Patient();
    Find_Patient();
    return 0;
}

PATIENT * Input_Patient()
{
    PATIENT *p1, *p2, *head;
    int flag = 1, x;

    head = (PATIENT *)malloc(sizeof(PATIENT));
    p1 = head;
   
    while (flag == 1)
    {
        p2 = (PATIENT *)malloc(sizeof(PATIENT));
        printf("请输入病人ID:");
        scanf("%s", p2->id);
        printf("请输入病人姓名:");
        scanf("%s", p2->name);
        printf("请输入病人性别:");
        scanf("%s", p2->sex);
        printf("请输入病人年龄:");
        scanf("%d", &p2->age);
        printf("请输入病人入院时间(年/月/日):");
        scanf("%d%d%d", &p2->year, &p2->month, &p2->day);
        printf("请输入病人病例:");
        scanf("%s", p2->cases);
        printf("请输入病人消费情况:");
        scanf("%s", p2->consumption);
        p1->next = p2;   
        p2->next = NULL;
        p1 = p2;
        printf("继续输入病人信息请按 1：");
        scanf("%d", &flag);
    }
    p1->next = NULL;
    printf("病人信息输入结束!\n是否保存病人信息？(1.是/2.否)\n");
    scanf("%d", &x);
    if (x == 1)
        Save_Patient(head);
    ///else
    ///Main_Patient();
    return head;
}
void Save_Patient(PATIENT *head)
{
    PATIENT *p;
    FILE *fp;
    if ((fp = fopen("patient", "a")) == NULL)
    {
        printf("打开文件过程出现错误！\n");
        ///Main_Patient();
    }
    for (p = head->next; p != NULL; p = p->next)
        fwrite(p, sizeof(PATIENT), 1, fp);
    fclose(fp);
    printf("病人信息已存入！\n");
}
void Find_Patient()
{
    PATIENT *p;
    FILE *fp;
    int x;
    char id[20], name[20];

    p = (PATIENT *)malloc(sizeof(PATIENT));

    printf("请选择你要使用的查找方式：\n");
    printf("1.通过ID查找\n");
    printf("2.通过姓名查找\n");
    scanf("%d", &x);
    if (x == 1)
    {
        printf("\n请输入病人ID：");
        scanf("%s", id);
        if ((fp = fopen("patient", "r")) == NULL)
        {
            printf("打开文件过程中出现错误！\n");
            exit(0);
        }
        while (!feof(fp))
        {
            fread(p, sizeof(PATIENT), 1, fp);
            if (strcmp(p->id, id) == 0)
            {
                printf("ID:%s\n姓名:%s\n性别:%s\n年龄:%d\n", p->id, p->name, p->sex, p->age);
                printf("入院时间：%02d/%02d/%02d\n病例：%s\n消费情况：%s\n", p->year, p->month, p->day, p->cases, p->consumption);
                break;
            }
        }
        fclose(fp);
    }
    else if (x == 2)
    {
        printf("\n请输入病人姓名：");
        scanf("%s", name);
        if ((fp = fopen("patient", "r")) == NULL)
        {
            printf("打开文件过程中出现错误！\n");
            exit(0);
        }
        while (!feof(fp))
        {
            fread(p, sizeof(PATIENT), 1, fp);
            if (strcmp(p->name, name) == 0)
            {
                printf("ID:%s\n姓名:%s\n性别:%s\n年龄:%d\n", p->id, p->name, p->sex, p->age);
                printf("入院时间：%02d/%02d/%02d\n病例：%s\n消费情况：%s\n", p->year, p->month, p->day, p->cases, p->consumption);
                break;
            }
        }
        fclose(fp);
    }
}