How to read a dbc and asc file in windows form in C++

You read them as binary files like any other file using for example the Windows API functions CreateFile / ReadFile or the C standard library fopen / fread functions. Before reading you have to determine the file size and allocate a buffer of that size plus one. The additional byte is for a trailing NULL byte to be appended after reading because both file types are plain text files.

Aftwerwards you can access the data as char* strings.

Note that opening in binary mode is required because only then the data are read as they are. Otherwise non-MS text files (LF only terminated lines) would be converted to CR - LF terminated lines making the allocarted buffer too small.

[EDIT]

Quote:

can i get a example code for that

#include <sys/stat.h>

struct stat st;
FILE *f = fopen("test.asc", "rb");
if (NULL != f)
{
    fstat(_fileno(f), &st);
    char *lpszFileData = new char[st.st_size + 1];
    fread(lpszFileData, 1, st.st_size, f);
    fclose(f);
    lpszFileData[st.st_size] = 0;
    // Use lpszFileData here

    // Delete when no longer needed
    delete[] lpszFileData;
}

[/EDIT]