I don't know : ) but i fix it, i save file on disk and read it from there. Furst i try to separate data from header in .bmp file, because i saw one function which draw on dc directly from data bits of .bmp, but something get wrong and save it on the disk. work fine now.

One possible reason that springs to mind is that the file somehow contains an embedded null. If this is true, strTemp probably *is* being added, but the embedded null stops the variable watch window from displaying the entire string. Also, if you try and use string manipulation routines on m_strFileBuffer, they will be affected by this null equally, and terminate the string early. To test if this is the problem, try modifying your code to this: CString strTemp; const int MAX_LINE_LENGTH_EXPECTED = 1024 ; TCHAR cBuffer[MAX_LINE_LENGTH_EXPECTED + 1]; while( ar.ReadString(cBuffer, MAX_LINE_LENGTH_EXPECTED) != NULL) { if (cBuffer[_tcslen(cBuffer) - 1] != _T('\r') && cBuffer[_tcslen(cBuffer) - 1] != _T('\n') ) { // We may have a prematurely-truncated string. // Or it will be the end of the file {:v) assert(false); <=== put breakpoint on this line. } m_strFileBuffer += strTemp + _T(" "); } If there's an embedded null, the character found at where it believes the end of the string is will *not* be the / it should be. Obviously the genuine end of the file may also not end with CR / LF, so be prepared for that. If you think your file might contain lines longer than 1024, adjust MAX_LINE_LENGTH_EXPECTED as appropriate.

m1m2 wrote: i have one button(browse) when click on it, it call CFileDialog.DoModal(). When user chose a file, the dialog thake the name and call to save it to another file Why? When the document saves its data, you will be presented with a Save As dialog where you can select the file to save to. It sounds as though you are reinventing the wheel. m1m2 wrote: OnSaveDocument("OneClock.one"); This function is called by the framework as part of the File Save or File Save As command. It is not called directly. m1m2 wrote: MyFileSaveFunction(), Serizlize() don't want to save my file The Serialize() method is used simply to get the data to/from the document from a CArchive object. It has no knowledge of files or where the data comes from. That's the document's job. "Money talks. When my money starts to talk, I get a bill to shut it up." - Frank "Judge not by the eye but by the heart." - Native American Proverb