sunum.c

学生成绩管理系统的开发

/*    sunum.c按用户需号排序浏览用户信息                   */
#include "stdio.h"
void SortByUserNum()
 {
    int i,j,k;
    user TmpS;
    user s[SIZE];/*SIZE，在shead.h头文件中定义的常量，值为100  */
    int recNumber = 0;
    char DataFile[40] = "yonghu";
    FILE *fp;/*====fp指针指向存储数据的文件名====*/
    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);
    }
   /*将文件中要排序的信息存入结构体数组*/
    while((fread(&TmpS,sizeof(user),1,fp)) != (int)NULL)
    {
        s[recNumber].Number = TmpS.Number;
        strcpy(s[recNumber].Name, TmpS.Name);
        strcpy(s[recNumber].ps,TmpS.ps);
        s[recNumber].power = TmpS.power;
        recNumber++;
    }
    fclose(fp);
/*====如果文件中有记录，则将各条记录按序号排序===*/
    if(recNumber>1)
    {
        /*====用选择排序法进行按序号的排序====*/
        for(i=0;i<recNumber-1;i++)
        {
            k = i;
            for(j=i+1;j<recNumber;j++)
            {
                if(s[k].Number<s[j].Number) k = j;
            }
            TmpS.Number = s[k].Number;
            strcpy(TmpS.Name,s[k].Name);
            strcpy(TmpS.ps,s[k].ps);
            TmpS.power = s[k].power;

            s[k].Number = s[i].Number;
            strcpy(s[k].Name,s[i].Name);
            strcpy(s[k].ps,s[i].ps);
            s[k].power = s[i].power;

            s[i].Number = TmpS.Number;
            strcpy(s[i].Name,TmpS.Name);
            strcpy(s[i].ps,TmpS.ps);
            s[i].power = TmpS.power;
        }

        /*====将排序好的结构体记录写入文件====*/
        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(user),1,fp)!=1)
            {
                printf("\nWrite file %s fail!end with anykey.\n",DataFile);
                perror("Write file fail!");
                    getch();
                    exit(1);
            }
        }
        fclose(fp);
    }

     /*====显示排序后的文件====*/
printf("The content in the user file is:.\n",DataFile);
    printf("Content as follow:\n");

    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("\nNumber \tName\tps    \tpower\n");
    while(fread(&TmpS,sizeof(user),1,fp) != (int)NULL)
    {
        printf("\n%ld     \t%s   \t%s\t  %d\n",TmpS.Number,TmpS.Name,TmpS.ps,TmpS.power);
    }
    fclose(fp);


 }