文件读写 (流)

文件读写操作 

 

   1:  // FileOperation.cpp : 定义控制台应用程序的入口点。
   2:  //
   3:   
   4:  #include "stdafx.h"
   5:  #include <iostream>
   6:  #include <stdio.h>
   7:  #include <stdlib.h>
   8:  #define MaxSize 100
   9:  using namespace std;
  10:   
  11:   
  12:  typedef struct RaderInfor
  13:  {
  14:      char flag;              //加 #  是为了保证数据正确,相当于一个校验的作用。
  15:      int dist[381];
  16:  } RaderInfor;
  17:  int main()
  18:  {
  19:      RaderInfor raderinfor[MaxSize]; //其实这也是初始化
  20:      //假如用指针的话,必须要用到new,这里没有用到指针。
  21:      memset(&raderinfor,0,sizeof(raderinfor));
  22:      raderinfor[0].flag = ‘#‘;
  23:      for(int i = 0; i < 381; i++)
  24:      {
  25:         raderinfor[0].dist[i] = 9;
  26:      }
  27:      raderinfor[1].flag = ‘#‘;
  28:      for(int i = 0; i < 381; i++)
  29:      {
  30:         raderinfor[1].dist[i] = 8;
  31:      }
  32:      /********************写文件到data.txt*****************/
  33:      FILE *outfile = fopen("data.txt","wb");//表示二进制文件
  34:      fwrite(&raderinfor,sizeof(RaderInfor),MaxSize,outfile); //100表示最多可存放多少个这样的数据类型。  这里的数据类型表示结构体,切记。
  35:      fclose(outfile);
  36:   
  37:      /*******************读文件到屏幕中*****************/
  38:      FILE *infile = fopen("data.txt","rb");
  39:      //需要定义一个结构体去接收存放在文件流中的数据才行。
  40:      //void *fptemp = malloc(sizeof(RaderInfor)*MaxSize);
  41:      RaderInfor raderinfor2[MaxSize]; //其实这也是初始化
  42:      fread(&raderinfor2,sizeof(RaderInfor),MaxSize,infile);   
  43:      for(int j = 0; j < MaxSize; j++)
  44:      {
  45:          cout << raderinfor2[j].flag << "  ";
  46:          if(raderinfor2[j].flag == ‘#‘)
  47:          {
  48:              for(int i = 0; i < 381; i++)
  49:             {
  50:               cout << raderinfor[j].dist[i] << " ";
  51:              }
  52:          }
  53:          cout << endl;
  54:      }
  55:      return 0;
  56:  }
  57:   

 

 

 

         下面在举一个文件读写例子,供大家参考:

 

   1:  #include <stdio.h>
   2:  #include <stdlib.h>
   3:   
   4:  typedef struct tagSTUDENTINFO{
   5:      int NO;
   6:      int Age;
   7:      // ...
   8:  } STUDENTINFO, *PSTUDENTINFO;
   9:   
  10:  void main()
  11:  {
  12:      int nStudent = 20;
  13:      PSTUDENTINFO pstruStudentInfo = (PSTUDENTINFO)malloc(sizeof(STUDENTINFO) * nStudent);
  14:   
  15:      pstruStudentInfo[0].NO = 1;
  16:      pstruStudentInfo[0].Age = 18;
  17:      pstruStudentInfo[1].NO = 2;
  18:      pstruStudentInfo[2].Age = 20;
  19:      // ...
  20:   
  21:      // write
  22:      FILE *outfile = fopen("data.txt", "wb");
  23:      fwrite(pstruStudentInfo, sizeof(STUDENTINFO), nStudent, outfile);  
  24:      fclose(outfile);
  25:   
  26:      // read
  27:      FILE *infile = fopen("data.txt", "rb");
  28:      void *ptemp = malloc(sizeof(STUDENTINFO) * nStudent);
  29:      fread(ptemp, sizeof(STUDENTINFO), nStudent, infile);
  30:      printf("NO: %d\tAge: %d\n", ((PSTUDENTINFO)ptemp)->NO, ((PSTUDENTINFO)ptemp)->Age);
  31:      fclose(infile);    
  32:  }

文件读写 (流)

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