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Writing struct to the file

Posted on 2000-03-05
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Last Modified: 2013-11-20
I tried to write and read the _RAL_ITEM
struct to file,but when read it,
the _RAL_ITEM struct from file contains
NULL data(such as strings...)
Here is definition:

typedef struct _TIME
{
      int iMin;
      int iHours;
      int iDay;
      int iMonth;
      int iYear;
};
typedef struct _RAL_ITEM
{
      int iIndex;
      UINT nType;
      CString sComment;
      CString sData      ;            
      _TIME time;
      BOOL bStopped;
      BOOL bDone;
};

I tried to write it to file this way:
 f.Write((void*)&item,sizeof(item));
-where f is opened file for writing
 and item is filled struct.

And read it this way:
 _RAL_ITEM item;
 f.Read((void*)&item,sizeof(item));
- where f is opened file for reading.
- after reading item.sData or
  item.sComment are empty(all data from
  struct are empty!!!

How to read it!!!
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Question by:radek_s
2 Comments
 
LVL 9

Accepted Solution

by:
ShaunWilde earned 200 total points
ID: 2584830
Your problem is that sComment and sData are CStrings and cannot be used in this way - you must either use archiving (CArchive) or replace sComment and sData
with fixed length char arrays

typedef struct _RAL_ITEM
{
int iIndex;
UINT nType;
char sComment[32]; // you decide the max length required for this field
char sData[128] ; // you decide the max length required here also
_TIME time;
BOOL bStopped;
BOOL bDone;
};

you can then use the methods you have described

0
 

Author Comment

by:radek_s
ID: 2585529
Adjusted points to 200
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