C / C++ / MFC

fantasy12151-Nov-07 20:57

fantasy1215

1-Nov-07 20:57

I define a winapp life m_font, a public data member of my derived CWinApp class,

But in the method

void CMyDialog::OnSelFontButton()
{
  CFontDialog dlg;
  if (dlg.DoModal() == IDOK)
  {
    CString strFace = dlg.GetFaceName();
    int iFontSize = dlg.GetFontSize();
    LOGFONT lf = {0};
    lf.lfWeight = iFontSize;
    _tcscpy(lf.lfFaceName,  strFace);
    
<FAILED>    theApp.m_font.CreateIndirectFont(&lf);
    
    m_MYEDITCTL.SetFont(&theApp.m_font);
  }
}

when I choose the font in the second time, I face a ASSERTION failure in the place <FAILED>. And I also tried a global definition, it failed in the same place too. Someone tell me why?

David Crow2-Nov-07 2:44

2-Nov-07 2:44

fantasy1215 wrote:
when I choose the font in the second time, I face a ASSERTION failure in the place <failed>.

What line of what file is asserting?

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Hamid_RT2-Nov-07 6:23

Hamid_RT

2-Nov-07 6:23

Does this line has error? theApp.m_font.CreateIndirectFont(&lf);?

fantasy12158-Nov-07 18:32

fantasy1215

8-Nov-07 18:32

This line doesn't have compile error.
But when running the exe, it faces the ASSERTION.
When I debug to trace, find the ASSERTION failed line is in that place.

Kernel mode: How to open a file with DeletePending?

Hamid_RT8-Nov-07 20:16

Hamid_RT

8-Nov-07 20:16

Well I am running your code and its working (I checked bor button) but I have two questions:
(1)did you check return value of CreateFontIndirect what was it?
(2)You said SetFont doesnt work it has two arguments second parameter is for redraw did you use of default(true)

JHoov1-Nov-07 12:30

JHoov

1-Nov-07 12:30

Sorry if this is the wrong place to post this...

I am writing a mini-filter which needs to open files before they are
deleted. I am filtering on _MJ_CLOSE and then checking the
DeletePending flag on the associated FILE_OBJECT. I need to open the
file for write access to wipe the contents, but no matter what I have
tried I always get a status STATUS_DELETE_PENDING from the Open
function. I have tried FltCreateFile, ZwCreateFile & IoCreateFile.

Can anyone shed some light on how this might be accomplished?

Thanks very much!
John

Correct Way to Terminate a Named Pipe Server

Richard Andrew x641-Nov-07 10:13

Richard Andrew x64

1-Nov-07 10:13

What is the accepted way to stop a thread from waiting on the ConnectNamedPipe() function?

I have tried terminating the thread with TerminateThread, and I have tried sending the pipe a special "terminate" message so that the thread can exit by itself.

But what is the accepted method?

Mark Salsbery1-Nov-07 11:02

Mark Salsbery

1-Nov-07 11:02

Closing the handle may do it.

I personally like using overlapped I/O with events.

There's an example here: one Use for Overlapped I/O[^]
(see the section "Overlapped I/O Usage")

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Richard Andrew x641-Nov-07 11:40

Richard Andrew x64

1-Nov-07 11:40

Thanks again, Mark. I see I'm not the first who ran up against this dilemma.

The overlapped method is brilliant in its simplicity. There is no need to call GetOverlappedResult() because we only need to know that the event has occurred!

Mark Salsbery1-Nov-07 11:47

Mark Salsbery

1-Nov-07 11:47

Independent123 wrote:
The overlapped method is brilliant in its simplicity. There is no need to call GetOverlappedResult() because we only need to know that the event has occurred!

Yeah, I like that Smile | :)

I don't like any blocking functions - I want total control!

Cheers,
Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Passing pointers to function into another function

Llasus1-Nov-07 13:57

Llasus

1-Nov-07 13:57

It was already answered, but don't try TerminateThread.. causes leaks most of the time. Properly signal the thread and close it from the inside to properly release your resources.

acerunner3161-Nov-07 10:04

Re: Passing pointers to function into another function

1-Nov-07 10:04

I'm trying to pass a pointer to a function as an argument to another function, but I am getting compile errors.

class CModule : public CDialog
{
// Construction
public:
   CModule (CWnd* pParent = NULL);   // standard constructor
   ...
private:
   unsigned char FunctTask1(unsigned char, unsigned char);
   unsigned char FunctTask2(unsigned char, unsigned char);
   unsigned char FunctTask3(unsigned char, unsigned char);
   void ManageTasks(unsigned char, unsigned char, unsigned char (*)(unsigned char, unsigned char));
};

unsigned char CModule ::FunctTask1(unsigned char Param1, unsigned char Param2)
{
   ...
}
unsigned char CModule ::FunctTask1(unsigned char Param1, unsigned char Param2)
{
   ...
}
unsigned char CModule ::FunctTask1(unsigned char Param1, unsigned char Param2)
{
   ...
}

void CModule ::ManageTasks(unsigned char Param1, unsigned char Param2, unsigned char (*ptrFunct)(unsigned char, unsigned char)
{
   ... //unrelated code removed

   switch (ptrFunction(1,1))
   {
   case 0:
      //handle results
   case 1:
      //handle results
   }

   ... //unrelated code removed
}

now based on a combobox selection, I will call a different function

void CModule::OnSelchangeCombobox()
{
   switch(m_Combobox->GetCurSel())
   {
   case 0: ManageTask(1,1,FunctTask1); break;
   case 1: ManageTask(1,1,FunctTask2); break;
   case 2: ManageTask(1,1,FunctTask3); break;
   }
}

but i get this error on compile

'ManageTasks' : cannot convert parameter 3 from 'unsigned char (unsigned char,unsigned char)' to 'unsigned char (__cdec<br />
l *)(unsigned char,unsigned char)'

What am I doing wrong? FYI I'm using VC++ 6.0.

Nemanja Trifunovic1-Nov-07 10:07

Nemanja Trifunovic

1-Nov-07 10:07

acerunner316 wrote:
What am I doing wrong?

From a quick glance at your code: you are trying to pass a pointer to a member-function where a pointer to a function is expected

Programming Blog
utf8-cpp

Re: Passing pointers to function into another function

acerunner3161-Nov-07 10:13

Re: Passing pointers to function into another function

1-Nov-07 10:13

so i have to specify in the argument list of 'ManageTasks' to expect a member function and not a regular function?

How do I do that?

David Crow1-Nov-07 10:44

Re: Passing pointers to function into another function

1-Nov-07 10:44

The methods FunctTask1(), FunctTask2(), FunctTask3() either need to be static or not a member of CModule.

acerunner3161-Nov-07 11:43

Re: Passing pointers to function into another function

1-Nov-07 11:43

In that case, I can't use it the way I had intended. I need FunctTask1,2,&3 to be able to access other member variables and functions that aren't static, so making it static wont work.

Time to rethink. Thanks for the help.

David Crow1-Nov-07 12:13

Re: Passing pointers to function into another function

1-Nov-07 12:13

acerunner316 wrote:
I need FunctTask1,2,&3 to be able to access other member variables and functions that aren't static, so making it static wont work.

You're not out of luck just yet. Two plausible solutions still exist. One is to change the third parameter of ManageTasks() to include CModule. I don't have the syntax readily available, but it's not uncommon and can easily be searched.

The other would be to create two versions of FunctTask1(), FunctTask2(), and FunctTask3(). One would be static and the other would not. That would look something like:

BYTE CModule::FunctTask1(BYTE Param1, BYTE Param2)
{
    // access CModule variables and functions
}
 
static BYTE CModule::FunctTask1(BYTE Param1, BYTE Param2, CModule *pThis )
{
    // call the non-static version
    return pThis->FunctTask1(Param1, Param2);
}
 
void CModule::ManageTasks(BYTE Param1, BYTE Param2, BYTE (*ptrFunct)(BYTE, BYTE), CModule *pThis )
{   
    ... //unrelated code removed   
    switch (ptrFunction(1, 1, pThis))   
    {   
        case 0: // handle results   
        case 1: // handle results   
    }   
 
    ... //unrelated code removed
}
 
void CModule::OnSelchangeCombobox()
{   
    switch(m_Combobox->GetCurSel())   
    {   
        case 0: ManageTask(1, 1, FunctTask1, this); break;   
        case 1: ManageTask(1, 1, FunctTask2, this); break;   
        case 2: ManageTask(1, 1, FunctTask3, this); break;   
    }
}

acerunner3161-Nov-07 12:22

Re: Passing pointers to function into another function

1-Nov-07 12:22

DavidCrow wrote:
You're not out of luck just yet. Two plausible solutions still exist. One is to change the third parameter of ManageTasks() to include CModule. I don't have the syntax readily available, but it's not uncommon and can easily be searched.

Tried that, see by reply to Randor below.

I will try the overloaded function way. However, one of the reason I wrote my code the way it is was so that I can easily add more functions later (ie FunctTask4,5,6 etc) without having to change much code. Just add a new case in the OnSelchangeCombobox function. I can still call ManageTask to do the same things. Having to overload every single one seems inefficient to me.

David Crow2-Nov-07 2:43

Re: Passing pointers to function into another function

2-Nov-07 2:43

acerunner316 wrote:
Having to overload every single one seems inefficient to me.

Indeed, I was just offering all the possibilities I could think of, and let you figure out which one would be best for your situation.

Mark Salsbery1-Nov-07 11:04

Mark Salsbery

1-Nov-07 11:04

In addition to DavidCrow's reply....

You can pass pointers to member functions but to
use them you have to have an object of the class
they are a member of, just like any class method call.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: Passing pointers to function into another function

Randor 1-Nov-07 11:44

Randor

1-Nov-07 11:44

typedef unsigned char (CModule::*FUNCPTR)(unsigned char,unsigned char);
ManageTask(1,1,&CModule::FunctTask1);

Re: Passing pointers to function into another function [modified]

acerunner3161-Nov-07 12:06