CreateFile ReadFile WriteFile Read-write file operation

The following is a description of this function: CreateFile This is a multifunctional function that can open or create the following objects and return accessible handles: console, communication resource, directory (read-only open), disk drive, file, mail slot, pipeline.

Handlewinapicreatefile (_in_lpctstrlpfilename, _in_dworddwdesiredaccess, _in_dworddwsharemode, _In_opt_LPSECURITY_ Attributeslpsecurityattributes, _in_dworddwcreationdisposition, _in_dworddwflagsandattributes, _In_opt_ Handlehtemplatefile);

For more details Click here for the description of the parameter: http://baike.baidu.com/view/1288759.htm

Here's how to read and write files using this function:

1. Read the file data:

HANDLE hopenfile = (HANDLE) CreateFile ("E:/a.txt", Generic_read, File_share_read, NULL, open_existing, NULL, NULL);
DWORD rsize;
int fileSize = 0;
CHAR *pbuffer;
if (Hopenfile = = INVALID_HANDLE_VALUE)
{
Hopenfile = NULL;

}

FileSize = GetFileSize (Hopenfile, NULL);

pbuffer = (CHAR *) malloc (fileSize);
ReadFile (Hopenfile, pbuffer, FileSize, &rsize, NULL);
Free (pbuffer);

CloseHandle (hfile);

2. Write file operation

DWORD dwBytesWritten = 0;

HANDLE hfile = CreateFile (
"E:/my.txt",//the name of the file or device created or opened (here is the TXT file).
generic_write,//file access rights, write
0,//sharing mode, where setting 0 prevents other processes from opening files or devices
Null,//security_attributes structure, security description, here NULL stands for default security level
create_always,//for operations that exist or do not exist, this is always created
file_attribute_normal,//setting the properties of the file with the cache option
NULL);

if (Hopenfile = = INVALID_HANDLE_VALUE)
{
Hopenfile = NULL;

}

char * Text = "Hello world!"
if (WriteFile (Hfile,text,strlen (text) +1,&dwbyteswritten,null) ==false)
{
cout<< "WriteFile ERROR" <<endl;
return 1;
};

CloseHandle (hfile);