Questions about MFC file reading and writing-CodePudding

/* */save the simulation data 
Void CIntelligentVehicleView: : OnSavetrace () 
{
CFileDialog fileDlg (FALSE); 
FileDlg. M_ofn. LpstrFilter="Text Files (*.txt) \ 0 *. TXT \ 0 all Files (*. *) \ 0 *. * \ \ 0 0"; 
If (IDOK==fileDlg. DoModal ()) 
{
//CFile file (fileDlg GetPathName (), CFile: : modeWrite); 
While (iter!=g_listPath. End ()) 
{

CNode curpos=* iter. 
CFile file; 
Cstrings STR. 
Cstrings strFilePath; 
StrFilePath=fileDlg. GetPathName (); 
//cstrings strFileName="mytest. TXT". 

SYSTEMTIME st. 
GetLocalTime (& amp; St); 

STR. The Format (" % 2 d: % 2 d: % 2 d % d % d \ r \ n ", st. wHour, st. wMinute, st. wSecond, curpos. X, curpos. Y); 
File. The Open (strFilePath, CFile: : modeCreate | CFile: : modeWrite | CFile: : modeNoTruncate); 

File. SeekToEnd (); 
File. The Write (LPCTSTR STR, STR., GetLength ()); 
File. The Close (); 
+ + iter. 

If (iter==g_listPath. End ()) 
break; 
} 
} 
} 



/* * refer to the simulation data/
Void CIntelligentVehicleView: : OnChecktrace () 
{
//TODO: Add your command handler code here 
//CFileDialog DLG (TRUE, "", NULL, OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT," (*.txt) | *. TXT | | "); 
//if (DLG) DoModal ()==IDOK) 
//{
//cstrings fileName=DLG. GetPathName (); 
//} 
CFileDialog fileDlg (TRUE); 
FileDlg. M_ofn. LpstrFilter="Text Files (*.txt) \ 0 *. TXT \ 0 all Files (*. *) \ 0 *. * \ \ 0 0"; 
If (IDOK==fileDlg. DoModal ()) 
{
CStdioFile mfile (fileDlg GetFileName (), CFile: : modeRead); 

Iter=g_listPath. The begin (); 
G_listPath. The clear (); 

Cstrings m_strTrace=""; 
The CNode curpos; 
//cstrings strFileName="mytest. TXT". 
Cstrings strnull=""; 
Cstrings, y=""; 
Int pos. 

//mfile. Open (strFileName CFile: : modeRead); 
While (mfile. ReadString (m_strTrace)) 
{
Pos=m_strTrace. Find (strnull); 
Y=m_strTrace. Right (pos - 2); 
Sscanf (x, y, "% d % d", & amp; (curpos. X), & amp; (curpos. Y)); 
G_listPath. Push_back (curpos); 
} 
Mfile. Close (); 
Loadtrace=true; 
} 
}

This is one I wrote about the file to read and write code, but after I save, read, did not save the document, also don't know what wrong, trouble great god help have a look, my level is limited, thank you

CodePudding user response:

//note written length
File. The Write (LPCTSTR STR, STR., GetLength () * sizeof (TCHAR));

CodePudding user response:

Just this question

CodePudding user response:

CFile file (fileDlg GetPathName (), CFile: : modeWrite);

To change to:

CFile file (fileDlg GetPathName (), CFile: : modeWrite | CFile: : modeCreate);

CodePudding user response:

No file, need the Create option

CodePudding user response:

reference 4 floor wuchuncai response:

no file, need to Create options

Now also is not saved in. TXT file this is how to return a responsibility

CodePudding user response:

reference 4 floor wuchuncai response:

no file, need to Create options

 
/* */save the simulation data 
Void CIntelligentVehicleView: : OnSavetrace () 
{
CFileDialog fileDlg (FALSE); 
FileDlg. M_ofn. LpstrFilter="Text Files (*.txt) \ 0 *. TXT \ 0 all Files (*. *) \ 0 *. * \ \ 0 0"; 
FileDlg. M_ofn. LpstrDefExt="TXT"; 
If (IDOK==fileDlg. DoModal ()) 
{

CFile file (fileDlg GetPathName (), CFile: : modeReadWrite | CFile: : modeCreate | CFile: : modeNoTruncate); 
While (iter!=g_listPath. End ()) 
{
Cstrings STR. 
SYSTEMTIME st. 
CNode curpos=* iter. 
GetLocalTime (& amp; St); 

File. The Open (fileDlg. GetPathName (), CFile: : modeReadWrite | CFile: : modeCreate | CFile: : modeNoTruncate); 
STR. The Format (" % 2 d: % 2 d: % 2 d % d % d \ r \ n ", st. wHour, st. wMinute, st. wSecond, curpos. X, curpos. Y); 
File. SeekToEnd (); 
File. The Write (LPCTSTR STR, STR., GetLength ()); 
File. The Close (); 
+ + iter. 

If (iter==g_listPath. End ()) 
break; 

} 
} 
}

The question now is written to a file open nothing inside! deliver

CodePudding user response:

 STR. The Format (" % 2 d: % 2 d: % 2 d % d % d \ r \ n ", st. wHour, st. wMinute, st. wSecond, curpos. X, curpos. Y); 
File. SeekToEnd (); 
File. The Write (LPCTSTR STR, STR., GetLength ());

This has a problem, Write not Write cstrings STR, can only Write the content, can be changed to:

 
STR. The Format (" % 2 d: % 2 d: % 2 d % d % d \ r \ n ", st. wHour, st. wMinute, st. wSecond, curpos. X, curpos. Y); 
File. SeekToEnd (); 

TCHAR TempStr [4096]. 
Memset (TempStr, 0409 6 * sizeof (TCHAR)); 
Lstrcpy (TempStr, STR); 

File. The Write (TempStr, lstrlen (TempStr) * sizeof (TCHAR));

CodePudding user response:

 STR. The Format (" % 2 d: % 2 d: % 2 d % d % d \ r \ n ", st. wHour, st. wMinute, st. wSecond, curpos. X, curpos. Y); 
File. SeekToEnd (); 
File. The Write (LPCTSTR STR, STR., GetLength ()); 
File. The Close ();

To:

 STR. The Format (" % 2 d: % 2 d: % 2 d % d % d \ r \ n ", st. wHour, st. wMinute, st. wSecond, curpos. X, curpos. Y); 
TCHAR * pBuffer=STR. GetBuffer (256); 
File. SeekToEnd (); 
nullnullnull