在ReadFile&中使用结构WriteFile函数用于读取和写入文件

问题描述

您能否让我知道如何通过Win32 Apis使用C中的数据结构从文件中写入和检索信息.
以下是示例代码，供您参考.

请让我知道我如何实现它.

Hi,
Can you please let me know how do i write and retrieve information from a file using data structures in C through Win32 Apis.
Below is the sample code for your reference.

Please let me know how do i achieve it.

#include <windows.h>

struct emp {
   int emp_id;
   char emp_name;
   int salary;
};

int main() {
   HANDLE hInfile = INVALID_HANDLE_VALUE;
   HANDLE hOutfile = INVALID_HANDLE_VALUE;
   const char* Infile = "c:\\test.dat";
   struct emp AnEmployee;


   /* Step1: Open test.dat for writing */
   hOutfile = CreateFile(Outfile, /* file to open */
                        GENERIC_WRITE, /* open for writing */
                        0, /* share for reading */
                        NULL, /* default security */
                        CREATE_NEW, /* existing file only */
                        FILE_ATTRIBUTE_NORMAL, /* normal file */
                        NULL); /* no att. template

   if(hOutfile == INVALID_HANDLE_VALUE) {
      fprintf(stderr, "Wrong file to open\n");
      return 0;
   }

   /* Step2: take input for user for employee details */
   /* Step3: write the data existing in structure to handle hOutfile */
   /* Step4: close hOutfile */


   /* Step5: open the test.dat for reading */ 
   hInfile = CreateFile(Infile, /* file to open */
                        GENERIC_READ, /* open for reading */
                        FILE_SHARE_READ, /* share for reading */
                        NULL, /* default security */
                        OPEN_EXISTING, /* existing file only */
                        FILE_ATTRIBUTE_NORMAL, /* normal file */
                        NULL); /* no att. template

   if(hInfile == INVALID_HANDLE_VALUE) {
      fprintf(stderr, "Wrong file to open\n");
      return 0;
   }

   /* Step6: read each record and then display emp_id, emp_name, salary to the user */
   /* Step7: print the output to the screen */
   /* Step8: close hInfile */
   return 0;
}

推荐答案

int nWritten;
BOOL bResult = WriteFile(hOutfile, &AnEmployee, sizeof AnEmployee, &nWritten, NULL);

要读回它，您可以使用 ReadFile()进行类似的操作 [ ^ ].

To read it back you do a similar operation using ReadFile()[^].

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