clearv.c

本源程序是一电子投票平台

ClearVote()
{
    int i,j,k;
    candidate TmpS;   /*定义进行操作时的临时结构体变量*/
    candidate s[10];/*10个候选人 */
    int recNumber;
    char DataFile[40] = "";
    /*DataFile存储候选人信息的文件名*/
    FILE *fp;/*====fp指针指向存储数据的文件名====*/
    /*提示用户输入要进行清空得票纪录的文件名*/
    printf("\nplease input the name of file where data is stored,end with enter key.\n");
    gets(DataFile);
    /*提示用户输入要进行清空得票纪录的文件名*/
    while(*DataFile == ('\0'))
    {
        printf("\nplease input the name of file where data is stored,end with enter key.\n");
        gets(DataFile);
    }
     /*以读的方式打开文件，如文件不存在，提示错误*/
    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);
    }
   /*将文件中的信息存入结构体数组*/
   recNumber=0;
   /*循环读取文件内容到结构体数组的同时，将票数项设为0后存入数组*/
    while((fread(&TmpS,sizeof(candidate),1,fp)) != (int)NULL)
    {
        TmpS.votenum=0;


            s[recNumber].Number = TmpS.Number;
            strcpy(s[recNumber].Name, TmpS.Name);
            strcpy(s[recNumber].intro,TmpS.intro);
            s[recNumber].votenum = TmpS.votenum;
            recNumber++;
    }
    fclose(fp);
   /*====将票数清零后的结构体数组记录写入文件====*/
        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);
     /*====显示得票数清零后的文件====*/
    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 clear is:\n");
    printf("\nNumber \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);
}