Re: Extracting a string from a tab-delimited file - C / C++ / MFC Discussion Boards

Re: Using 2 thread i receive a message " Access violation reading location 0x0000001c ". The cmd that generate the error is simply CString utilization...

Stuart Dootson1-Apr-09 21:44

Stuart Dootson

1-Apr-09 21:44

SNArruda wrote:
so, there are a way to start a function directly in a UI Thread context from worker thread context

Not really - although if you send/post a message to one of the UI thread's windows, the message handler will be executed in the UI thread - that's about the best way of communicating between worker and UI threads.

SNArruda wrote:
wy the data needs to be locked before your use ? ... each context don´t have your own data ... or for example the data STPacoteFabrica::p_sPacoteFabrica (CString having a path for a diretory) belong of 2 context´s ?

Class members, heap allocated data - it's all visible to both threads. If the UI thread modifies some data while the worker thread is accessing it...you've got a problem. If the worker thread modifies some data while the UI thread is accessing it...you've got a problem. You use locks to ensure that only one thread can access data at a time.

Can I suggest you look at some introductory thread information? There are several on CP[^].

SNArruda wrote:
There are way to attach files here ? I would like to attach the .h and .cpp files

I don't believe there are.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Using 2 thread i receive a message " Access violation reading location 0x0000001c ". The cmd that generate the error is simply CString utilization...

ThatsAlok1-Apr-09 18:19

ThatsAlok

1-Apr-09 18:19

have you applied some type of syncronization mechanism in your program. if not, try critcal_section

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
Never mind - my own stupidity is the source of every "problem" - Mixture

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
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Re: Using 2 thread i receive a message " Access violation reading location 0x0000001c ". The cmd that generate the error is simply CString utilization...

SNArruda2-Apr-09 14:30

SNArruda

2-Apr-09 14:30

Tanks Alok Gupta,

I'll study the critical_section.

But, one thing resistance to go into my mind.

I have two threads. The primary thread that corresponding to UI thread and a worker thread.

There are a way to call, from a Worker thread, a function in primary thread context without messages. Simply geting a pointer and starting it.

Another example, if i create another worker thread, so, i will have a primary thread, worker_thread_1 and worker_thread_2, and will desired call from worker_thread_1::fx(), from its context, the worker_thread_2::fy(), in its own context.

I Realy need to do this, or samething like.

if you need, see my .h and .cpp files attached early

How can I use GetModify/SetModify within CRichEditView

Joseph Marzbani1-Apr-09 11:36

Joseph Marzbani

1-Apr-09 11:36

I've a SDI Application and want to Enable/Disable some menu items under some specific conditions. My CAppView is derived from CRichEditView and I used the following code to find if it's changed since I set the Modification Flah (using SetModify) or not:

//Some conditions
GetRichEditCtrl().SetModify( FALSE ) ;

//Some other conditions
GetRichEditCtrl().SetModify( TRUE ) ;

/////////////////////////////////////////////////

if ( GetRichEditCtrl().GetModify() )
{
    // Do something
}

but GetRichEditCtrl().GetModify() allways returns TRUE, even if I set GetRichEditCtrl().SetModify( TRUE )

Any idea?

Thank you masters!

Re: How can I use GetModify/SetModify within CRichEditView

Rick York1-Apr-09 11:49

Rick York

1-Apr-09 11:49

Look at the usage of the ON_UPDATE_COMMAND_UI macro.

Re: How can I use GetModify/SetModify within CRichEditView

Stuart Dootson1-Apr-09 11:57

Stuart Dootson

1-Apr-09 11:57

Jusef Marzbany wrote:
but GetRichEditCtrl().GetModify() allways returns TRUE, even if I set GetRichEditCtrl().SetModify( TRUE )

You use GetRichEditCtrl().SetModify( FALSE ) to reset the modification flag to false - see here[^].

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Extracting a string from a tab-delimited file

SomeGuy6541-Apr-09 11:19

SomeGuy654

1-Apr-09 11:19

I'm trying to create a small function for a program that should extract the data as a string from a column of a tab delimited text file. It seems to be returning an empty string though.

Let me know if you notice what's wrong with this function. Edit: this is VC++

Function:

string split_row(string line, int column)
{
	// The first column would be column 1 for this function. Pass in the string 
	// we want to parse and the column we want parsed. Will return just the string 
	// from the column indicated for this row.

	int c_temp;
	string data;
	int pos;
	const string delimiter = "\t";

	for(c_temp=1; c_temp<=9; c_temp++)
	{
		pos = line.find_first_of(delimiter);
		if (c_temp != column)
		{
			line.erase(0, pos);
		}
		else
		{
			data = line.substr(0, pos-1);
			break;
		}
	}
	return data;
}

If the string "row", below, were to be:

12	test Phone	2009

And we called split_row(row, 2) it should return "test Phone".

Thanks! (sorry for the stupid username)

Re: Extracting a string from a tab-delimited file

Stuart Dootson1-Apr-09 12:05

Stuart Dootson

1-Apr-09 12:05

This code (changed bits in bold) seems to work with your test data. I suspect you were forgetting that ranges in STL are half-open, i.e. the last character in the range specification isn't part of the range.

string split_row(string line, int column)
{
// The first column would be column 1 for this function. Pass in the string 
// we want to parse and the column we want parsed. Will return just the string 
// from the column indicated for this row.

   int c_temp;
   string data;
   int pos;
   const string delimiter = "\t";

   for(c_temp=1; c_temp<=9; c_temp++)
   {
      pos = line.find_first_of(delimiter);
      if (c_temp != column)
      {
         line.erase(0, pos+1);
      }
      else
      {
         data = line.substr(0, pos);
         break;
      }
   }
   return data;
}

Ought to add a check that pos != std::string::npos, as that indicates no tab, so a possible error condition.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Extracting a string from a tab-delimited file

SomeGuy6541-Apr-09 14:13

SomeGuy654

1-Apr-09 14:13

Works perfectly with your change. Thank you very much!

XML Visual Studio 2003 MFC C++

ScotDolan1-Apr-09 10:59

ScotDolan

1-Apr-09 10:59

I am developing a new software driver. The software will be package into DLL. I would like to store the configuration information for the DLL in a XML file.. I found lots of different XML Parser pojects on Code Project. However, i would prefer to use one from msdn if there is one available. Does anyone have any recomendations.

Scott

Scott Dolan
Jernie Corporation
Engineering & Manufacturing
Software, Hardware, & Enclosures

Re: XML Visual Studio 2003 MFC C++

CPallini1-Apr-09 11:09

CPallini

1-Apr-09 11:09

ScotDolan wrote:
i would prefer to use one from msdn if there is one available

I bet there is [^].
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Re: XML Visual Studio 2003 MFC C++

Stuart Dootson1-Apr-09 11:55

Stuart Dootson

1-Apr-09 11:55

If you don't want to use MSXML, there is an alternative[^] from MS that claims to be 'lighter'.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

safe-cast serialization

Member 26037721-Apr-09 7:57

Member 2603772

1-Apr-09 7:57

Is there a way in C++ to serialize objects into a char buffer without using reinterpret_cast or c-style casting (and backwards on the other end)? I also don't want to use C++ streams. I don't care how difficult it is.
Thanks

Re: safe-cast serialization

CPallini1-Apr-09 8:09

CPallini

1-Apr-09 8:09

IMHO your requirements are not wise (why do you want to avoid cast?).
Smile | :)

Re: safe-cast serialization

Member 26037721-Apr-09 9:45

Member 2603772

1-Apr-09 9:45

c-style cast is dangerous and hard to find in code. reinterpret_cast is not portable and just as dangerous as c-style. i want a typed way to serialize/deserialize.

Re: safe-cast serialization

CPallini1-Apr-09 10:50

CPallini

1-Apr-09 10:50