/* modnum.c ：輸入序號(hào)修改候選人簡(jiǎn)介*/
#include "stdio.h"
void ModifyIntro()
 {
    int i,j,k;
    long modnum;    /*存儲(chǔ)用戶(hù)輸入的要修改的候選人序號(hào)*/
    /*輸入各項(xiàng)修改后信息*/
    long Number;
    char Name[20];
    char intro[80];


    candidate TmpS;   /*定義進(jìn)行操作時(shí)的臨時(shí)結(jié)構(gòu)體變量*/
    candidate s[10];/*10個(gè)候選人 */
    int recNumber;
    char DataFile[40] = "",next;
    /*DataFile存儲(chǔ)候選人信息的文件名，next為是否進(jìn)行下一次刪除操作的選項(xiàng)*/
    FILE *fp;/*====fp指針指向存儲(chǔ)數(shù)據(jù)的文件名====*/
    /*提示用戶(hù)輸入要進(jìn)行修改記錄的文件名*/
    printf("\nplease input the name of file where data is stored,end with enter key.\n");
    gets(DataFile);
    /*提示用戶(hù)輸入要進(jìn)行修改記錄的文件名*/
    while(*DataFile == ('\0'))
    {
        printf("\nplease input the name of file where data is stored,end with enter key.\n");
        gets(DataFile);
    }

begin:
    /*以讀的方式打開(kāi)文件，如文件不存在，提示錯(cuò)誤*/
    fp=fopen(DataFile,"rb");
    if (fp == NULL)
    {
        printf("\nOpen file %s fail!End with any key\n",DataFile);
        perror("Open file fail");
        getch();
        exit(1);
    }
    printf("please input the Employee'seatnum which you will modify:");
    scanf("%ld",&modnum);
    printf("the candidate you will modify is:%ld\n",modnum);
    /*輸入要修改記錄的各項(xiàng)內(nèi)容值，管理員只能修改姓名和介紹*/
    Number=modnum;
    printf("name=");
    scanf("%s",Name);

    getchar();
    printf("intro=");
    gets(intro);

   /*將文件中要修改的信息存入結(jié)構(gòu)體數(shù)組*/
   recNumber=0;
   /*循環(huán)將文件數(shù)據(jù)讀入結(jié)構(gòu)體數(shù)組，
   如文件中的數(shù)據(jù)候選人號(hào)和要修改的候選人號(hào)不符，則原樣寫(xiě)入數(shù)組，
   如文件中數(shù)據(jù)的候選人號(hào)和要修改候選人號(hào)匹配，
   則根據(jù)用戶(hù)輸入的各項(xiàng)修改內(nèi)容重新賦值，即修改，并寫(xiě)入數(shù)組*/
    while((fread(&TmpS,sizeof(candidate),1,fp)) != (int)NULL)
    {
        if(TmpS.Number!=modnum)
            {
            s[recNumber].Number = TmpS.Number;
            strcpy(s[recNumber].Name, TmpS.Name);
            strcpy(s[recNumber].intro,TmpS.intro);
            s[recNumber].votenum = TmpS.votenum;

            recNumber++;
            }
        else
            {
            s[recNumber].Number = Number;
            strcpy(s[recNumber].Name, Name);
            strcpy(s[recNumber].intro,intro);
            s[recNumber].votenum = TmpS.votenum;
            /*管理員不可以修改選票，所以選票數(shù)仍為文件中原值*/

            recNumber++;
            }

    }
    fclose(fp);
   /*====將修改后的結(jié)構(gòu)體數(shù)組記錄寫(xiě)入文件====*/
        fp=fopen(DataFile,"wb+");
        if (fp == NULL)
        {
            printf("\nSet up file %sfail !end with anykey.\n",DataFile);
            perror("Set up fail");
            getch();
            exit(1);
        }


        for(i=0; i<recNumber; i++)
        {
            if(fwrite(&s[i],sizeof(candidate),1,fp)!=1)
            {
                printf("\nWrite file %s fail!end with anykey.\n",DataFile);
                perror("Write file fail!");
                    getch();
                    exit(1);
            }
        }
        fclose(fp);
     /*====顯示修改后的文件====*/
    fp=fopen(DataFile,"rb");
    if (fp == NULL)
    {
        printf("\nOpen file%sfail!End with any key \n",DataFile);
        perror("Open file fail");
        getch();
        exit(1);
    }
    printf("the file after modify is:\n");
    printf("\nNumber \t\tName\tintro\tvotenum\n");
    while(fread(&TmpS,sizeof(candidate),1,fp) != (int)NULL)
    {
        if(TmpS.Number!=0)
        printf("\n%ld\t        %s\t   %s\t  %d\n",TmpS.Number,TmpS.Name,TmpS.intro,TmpS.votenum);
    }
    fclose(fp);
/*提示是否進(jìn)行下一次修改*/
    printf("\nGo on ?(y/n)");
    next=getche();
    putchar('\n');
    if ( next =='y' || next =='Y') goto begin;
 }