程序代码：

/*通讯簿*/
#include<stdio.h>
struct person
{
    char name[8];
    char num[10];
    char ege[5];
    char sex[5];
    char tel[15];       
    char addr[50];
};
char filename[20];
FILE *fp;
void creat();
void output();
void search();
void append();
void modify();
void delete();
void main()
{
    int m;

    creat(); 
    while(1)
    {
        printf("\n\n添加，请按1");
         printf("\n查找，请按2");
        printf("\n修改，请按3");
        printf("\n删除，请按4");
        printf("\n输出，请按5");
        printf("\n退出，请按0\n");
        scanf("%d",&m);
        if(m>=0&&m<=5)
        {
            switch(m)
            {
            case 1: append();
                    break;
            case 2: search();
                    break;
            case 3: modify();
                    break;
            case 4: delete();
                    break;
            case 5: output();
                    break;
            case 0: exit();
            }
         printf("\n\n操作完毕，请再次选择！");
         }
        else
            printf("\n\n选择错误，请再次选择！");
    }
}

void creat()
{
    struct person one;
    long s1;
    printf("\n请输入通讯簿名：");
    scanf("%s",filename);
    if((fp=fopen(filename,"w"))==NULL)
    {
        printf("\n不能建立通讯簿！");
        exit();
    }
    fprintf(fp,"%-10s%-10s%-6s%-6s%-20s%-50s\n","姓名","学号","年龄","性别","电话号码","住址");
    printf("\n请输入姓名、学号、年龄、性别、电话号码及住址（以0结束）\n");       
    scanf("%s",one.name);
    while(strcmp(one.name,"0"))
    {
        scanf("%s%s%s%s%s",one.num,one.ege,one.sex,one.tel,one.addr);                       
        fprintf(fp,"%-10s%-10s%-6s%-6s%-20s%-50s\n",one.name,one.num,one.ege,one.sex,one.tel,one.addr);
        scanf("%s",one.name);
    }
    fclose(fp);
    system("pause");
}
void output()
{
    struct person one;
    if((fp=fopen(filename,"r"))==NULL)
    {
        printf("\n不能打开通讯簿！");
        exit();
    }
    printf("\n\n%20s\n","通 讯 簿");
    while(!feof(fp))
    {
        fscanf(fp,"%s%s%s%s%s%s\n",one.name,one.num,one.ege,one.sex,one.tel,one.addr);   
        printf("%-10s%-10s%-6s%-6s%-20s%-50s",one.name,one.num,one.ege,one.sex,one.tel,one.addr);
    }
    fclose(fp);
}
void append()
{
    struct person one;
    if((fp=fopen(filename,"a"))==NULL)
    {
        printf("\n不能打开通讯簿！");
        exit();
    }
    printf("\n请输入添加的姓名、学号、年龄、性别、电话号码及住址\n");       
    scanf("%s%s%s%s%s%s",one.name,one.num,one.ege,one.sex,one.tel,one.addr);       
    fprintf(fp,"%-10s%-10s%-6s%-6s%-20s%-50s\n",one.name,one.num,one.ege,one.sex,one.tel,one.addr);
    fclose(fp);
}
void search()
{
    int k=0;
    char namekey[8];
    struct person one;
    printf("\n请输入姓名:");
    scanf("%s",namekey);
    if((fp=fopen(filename,"rb"))==NULL)
    {
        printf("\n不能打开通讯簿！");
        exit();
    }
    while(!feof(fp))
    {
        fscanf(fp,"%s%s%s%s%s%s\n",one.name,one.num,one.ege,one.sex,one.tel,one.addr);
        if(!strcmp(namekey,one.name))
        {
            printf("\n\n已查到，记录为：");
            printf("\n%-10s%-10s%-6s%-6s%-20s%-50s",one.name,one.num,one.ege,one.sex,one.tel,one.addr);
            k=1;
        }
    }
    if(!k)
        printf("\n\n对不起，通讯簿中没有此人的记录。");
    fclose(fp);
}
void modify()
{
    int m,k=0;
    long offset;
    char namekey[8];
    struct person one;
    printf("\n请输入姓名:");
    scanf("%s",namekey);
    if((fp=fopen(filename,"r+"))==NULL)
    {
        printf("\n不能打开通讯簿！");
        exit();
    }
    while(!feof(fp))
    {
        offset=ftell(fp);
        fscanf(fp,"%s%s%s%s%s%s\n",one.name,one.num,one.ege,one.sex,one.tel,one.addr);
        if(!strcmp(namekey,one.name))
        {
            k=1;
            break;
        }
    }
    if(k)
    {
        printf("\n已查到，记录为：");
        printf("\n%-10s%-10s%-6s%-6s%-20s%-50s",one.name,one.num,one.ege,one.sex,one.tel,one.addr);
        printf("\n请输入新姓名、学号、年龄、性别、电话号码及住址：");
        scanf("%s%s%s%s%s%s",one.name,one.num,one.ege,one.sex,one.tel,one.addr);
        fseek(fp,offset,SEEK_SET);
        printf("%ld",ftell(fp));
        fprintf(fp,"%-10s%-10s%-6s%-6s%-20s%-50s\n",one.name,one.num,one.ege,one.sex,one.tel,one.addr);
    }
    else
        printf("\n对不起，通讯簿中没有此人的记录。");
    fclose(fp);
}
void delete()
{
    int m,k=0,flag;
    long offset1,offset2;
    char namekey[8], valid[4];
    struct person one;
    printf("\n请输入姓名:");
    scanf("%s",namekey);
    if((fp=fopen(filename,"r+"))==NULL)
    {
        printf("\n不能打开通讯簿！");
        exit();
    }
    while(!feof(fp))
    {
        offset1=ftell(fp);
        fscanf(fp,"%s%s%s%s%s%s\n",one.name,one.num,one.ege,one.sex,one.tel,one.addr);
        if(!strcmp(namekey,one.name))
        { 
            k=1;
            break;
        }
    }
    if(k)
    {
        printf("\n已查到，记录为");
        printf("\n%-10s%-10s%-6s%-6s%-20s%-50s",one.name,one.num,one.ege,one.sex,one.tel,one.addr);
        printf("\n确实要删除,按1；不删除，按0：");
        scanf("%d",&m);
        if(m)
        { 
            fseek(fp,offset1,SEEK_SET);
            fprintf(fp,"%-10s%-10s%-6s%-6s%-20s%-50s\n","","","","","","");
        }
    }
    else
        printf("\n对不起，通讯簿中没有此人的记录。");
    fclose(fp);
}

编译没问题  运行也没问题   就是在输入第二个联系人时  窗口无故消失  求救？？？