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You need to UnmapViewOfFile those FMO when you are done. Also make sure to CloseHandle the FMO's 'file' handle after unmapping the view to it. There is no reason you could not run 'indefinitely' if the proper cleanup is performed.
We use FMO in our apps, and our apps run for months at a time.
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I am writing a c++ program to encrypt/decrypt files. my instructor wants to start this program by right clicking on the file to be encrypted/decrypted and then choosing the option Encrypt/Decrypt among the list that appears when any file is right-clicked. Can anyone help me with that?
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Meaning you probably need a context menu handler that responds to all file selections.
Selection of items from the context menu will invoke your program to encrypt/decrypt the selected file(s).
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Thank you. This is exactly what i was looking for 
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Hi,
I want to send an email through my VC++ app with out anyone knowing( in the back ground). We have Lotus notes as the email client. Can anyone please suggest How to do this? Thanks a Lot!
Murthy
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okay...i have written a program that calculates prime number till u stop the program. Now, what happens it that while calculating the numbers or calculating any mathematical equation for that matter, the program only manages to use a small portion of the CPU. How can i utilize the whole CPU. SOmething like multithreading. In basic terms, i want to calculate the number as fast as possible!!
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What is it your program does that it does not consume more CPU time? If you had a tight loop performing only math, then your program should be using a LOT of the CPU time as the foreground process. In this case it does not make sense to split into multiple threads, you would just be wasting more time switching the context. Do you output to screen or wait for user or something? Typically you only multiple thread if you need to handle user input while calculating something, or your program responds to user input while checking mail, or waiting for characters from the modem, or reading and writing to the files on the hard drive or something else like that, where there are distinct different actions, some of which involve 'waiting' for soemthing. Your program seems very straight forward and should probably remain single threaded.
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yeah, youre right. In a tight loop it does use all of the CPU.
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Check out SetThreadPriority()
"You're obviously a superstar." - Christian Graus about me - 12 Feb '03
"Obviously ??? You're definitely a superstar!!!" mYkel - 21 Jun '04
Within you lies the power for good - Use it!
Honoured as one of The Most Helpful Members of 2004
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Hi
I am downloading some files from FTP server through a VC++ app. I need to display progress bar ( possibly standard windows dialog for copying showing the progress ) Can anyone point me to the right classes, sample code, or give some suggestions? Any help is greatly appreciated. Thanks in Advance!!
Murthy
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Iam not sure what you want here ...
1.If you want to display the progres s,then u can use progress control .CProgressCtrl is the class.
2.CFtpConnection is teh class for FTP
Cause is my effort;
Effect is God's effort
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I don't know where should i place this topic (databases or here)... whatever 
My question is...
Is there any way to create function that can return a recordset? i tried to do it but...
i forgot... the other thing is how to "catch" returned recordset? does CRecordset have any copy constructor or sth?
any ideas? please .
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scoroop wrote:
Is there any way to create function that can return a recordset? i tried to do it but...
But what? Show us the code that you had/have and what the problem is.
scoroop wrote:
does CRecordset have any copy constructor...
No.
scoroop wrote:
does CRecordset have any...sth?
What is sth?
"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown
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first of all ... what is sth? in every english/foreign language dictionary they use "sth" instead of "something" .
ok and now straight to the point:
i need a function that queries database and that returns results as CRecordset:
<br />
CRecordset* CDB::Query(CString path, CString SQLstring)<br />
{<br />
...some declarations... <br />
<br />
TRY <br />
{<br />
...i open database and then:<br />
<br />
CRecordset* recset = new CRecordset(&db);<br />
recset.Open(CRecordset::forwardOnly, SQLstring, CRecordset::readOnly);<br />
return recset; <br />
db.Close();<br />
}<br />
CATCH(CDBException, dbex)<br />
{<br />
AfxMessageBox("Error: " + dbex->m_strError);<br />
}<br />
END_CATCH;<br />
}<br />
Than in the other class i'd like to use it...
<br />
CDB d;<br />
CRecordset *recset = d.Query(path,sqlstring);<br />
the result is that program compiles, when i run procedure form the second code snippet it's fine but recordset is "poisoned" . when i use any method of CRecordset class i get "debug assertion failed" error. i'm not too good in pointer stuff so it's quite possible it's something trivial .
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scoroop wrote:
in every english/foreign language dictionary they use "sth" instead of "something"
Not in any dictionary that I have ever owned or used. That must be one of those online-specific things where folks type r instead of are and ur instead your.
scoroop wrote:
db.Close();
Why are you closing the database?
scoroop wrote:
when i use any method of CRecordset class i get "debug assertion failed" error.
It would help if you indicated what line of what file fired the assertion.
"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown
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Not in any dictionary that I have ever owned or used. That must be one of those online-specific things where folks type r instead of are and ur instead your.
not at all... i have oxford collocations dictionary and collins dictionary... they use it as well. check it and you'll see it's quite common .
Why are you closing the database?
shouldn't i do it at the end of a function? if you say so, i assume that returned recordset passed to another function will need access to db. anyway i don't close db now but the result is the same...
what line of what file fired the assertion.
depends on the function that i use. when i want to browse recordset
recset->GetFieldValue(1,str);
i get error in afxdb.h line 680 and when i press retry i receive window with dbcore.cpp line 1920 (so it all stops on the method i used).
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scoroop wrote:
they use it as well
Please provide an example.
scoroop wrote:
shouldn't i do it at the end of a function?
Only if you don't want to use it any more.
scoroop wrote:
i get error in afxdb.h line 680
This must not be Visual Studio v6 because line 680 of afxdb.h nor line 1920 of dbcore.cpp are assertions.
"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown
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it's VS 2003.
infact if i don't find solution for my problem i'll change that function a bit and use it as __inline, because query and its result are proper. the only problem is passing it to another class... anyway, my code above seems to be ok? i'm affraid that there might be something wrong with pointers...
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scoroop wrote:
the only problem is passing it to another class
What does the code look like that passes the pointer to the other class' methods? And then what do those methods look like? It's hard to offer a solution to something when not all of the pieces have been shown.
"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown
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the other class is a window (dialog) class so there's nothing special. i click a button. it launches OnClickedButton function which calls my function Query(...) which is supposed to return recordset. then i want to browse it, extract necessary data and put it into listbox. and that's all. so the code i provided is almost complete. but i'll try to give you some more...
<br />
CRecordset* CDB::Query(CString path, CString SQLstring)<br />
{<br />
CDatabase db;<br />
CString driver,dsn;<br />
<br />
driver = GetDriver();
<br />
dsn.Format("ODBC;DRIVER={%s};DSN='';DBQ=%s", driver, path);<br />
<br />
TRY <br />
{<br />
db.Open(NULL, false, false, dsn);<br />
CRecordset* recset = new CRecordset(&db);<br />
recset->Open(CRecordset::forwardOnly, SQLstring, CRecordset::readOnly);<br />
return recset; <br />
}<br />
CATCH(CDBException, dbex)<br />
{<br />
AfxMessageBox("Error: " + dbex->m_strError);<br />
}<br />
END_CATCH;<br />
}<br />
and then in OnClickedButton
<br />
void CBaseWindow::OnClickedButton1()<br />
{<br />
...
CString val;<br />
CDB d;<br />
CRecordset *recset = d.Query(path,sqlstring);<br />
<br />
<br />
short fields = recset->GetODBCFieldCount();<br />
while(!recset.IsEOF())<br />
{<br />
for(short i=0;i<fields;i++)<br />
{<br />
recset->GetFieldValue(i,val);<br />
}<br />
recset->MoveNext();<br />
}<br />
}<br />
that's the whole story...
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I suspect the problem lies with db being a local variable in the Query() method. Once it goes out of scope, the database is closed.
"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown
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thanks a million . seems to be ok now .
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I have programmed a DLL in order to encapsulate some code that is polling data from a USB peripheral unit. The user of the DLL must be able to define his own handler for that "Snapbutton" event.
To acheive this i am passing a function pointer to the DLL. The DLL then is calling back this function every time the event is detected on the peripheral unit.
This is working ok with the except that accessing MFC member functions does NOT always work. if i pass a pointer to the following function to my DLL i hear the beep every time the DLL calls the function but the checkbox is not set:
void CDemoDlg::SnapButtonHandler()<br />
{<br />
m_check_snap.SetCheck(TRUE); <br />
Beep(4000,50);<br />
}<br />
i have tried this code in a minimalist MFC application and it worked well but within a more complex MFC application it didn't work.
i suppose that calling an MFC member function from outside the MFC framework causes some problems. does anybody have an idea how i could solve that problem?
here is the code loading the DLL and passing the function pointer to it:
<br />
CEM2800DLLDemoDlg dlg;<br />
<br />
void HandleSnapButton() {dlg.SnapButtonHandler();}<br />
<big><br />
if i directly pass a pointer to a mfc member function to the DLL,<br />
i get an "illegal call of a non-static member function" error<br />
that is why i define that global function "HandleSnapButton"<br />
</big><br />
typedef BYTE (CALLBACK* SetSnapButtonHandlerType) (void(*ptr)()); <br />
<br />
<br />
void LoadSnapButtonDLL(void (*pHnd) ())<br />
{ <br />
if (!hClcltr) hClcltr=LoadLibrary(szDLLName);<br />
<br />
if (hClcltr) <br />
{ <br />
pSetSnapButtonHandler = (SetSnapButtonHandlerType)GetProcAddress( <br />
hClcltr,"SetSnapButtonHandler");<br />
<br />
if (pSetSnapButtonHandler) pSetSnapButtonHandler(pHnd);}<br />
}<br />
The DLL is loaded and the callback function pointer is passed to the DLL by LoadSnapButtonDLL(&HandleSnapButton);
Has anybody an idea why the access to methods of the MFC member variables like m_check_snap.SetCheck(TRUE); within the callback function are without effect?
i must admit i am a still a beginner in C++ and MFC programming so i would be very thankful for every hint.
Danny Kaiser
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