Re: STL ? - C / C++ / MFC Discussion Boards

Mike_Beard26-Jun-02 10:13

26-Jun-02 10:13

Thanks for the reply Chris!

After seeing the great (and daunting) data that Ernest posted, I am beginning to think you're right.

I was hoping for something that I could do in a couple of days (it doesn't have to be pretty, it just needs to work) but this has the appearance of a full fledged, several weeks project. More time than I want to put in, I think.

Re: Outlook Express data format

Ernest Laurentin26-Jun-02 8:58

Ernest Laurentin

26-Jun-02 8:58

File format for Outlook Express 5.0 DBX files

Header:

These are the values we use to see what type the file is.

0x0 Signature [16/32 bytes]
= 4A4D4636 03001000 /* OE4 SIGNATURE */
= CFAD12FE C5FD746F 66E3D111 9A4E00C0 /*OE5 Email DBX*/
= CFAD12FE C6FD746F 66E3D111 9A4E00C0 /*OE5 Folder DBX*/

As I said, we use these values to identify it, but we don't know
what these values mean

0x5C Highest Email ID [4 bytes]
This is the current highest. The next email will have a number
one higher than this.

0x7C File Size [4 bytes]
Total size of file

0xC4 Item Count [4 bytes]
Number of items stored in this DBX file. Appears to be
accurate. We use it as a second check that we haven't gone wrong
whilst reading the indexes.

0xE4 Index Pointer [4 bytes]
File offset pointing to a page of Data Indexes. This page can
even be a page of Indexes pointing to pages of indexes. This area
needs to be explored a little more

Indexes: (pointed to by the pointer in 0xE4)

This area is a little blurry, but it appears to work

0x0 Self [4 bytes] - Current Offset
0x4 Unknown [4 bytes]
0x8 Table Pointer [4 bytes] - Pointer to another of these tables
0xC Parent [4 bytes] - If this is a table of indexes which is
referenced by another table above it,
this will point to the parent's table
0x10 Unknown [1 byte]
0x11 Pointer Count [1 byte] - Number of pointers in this table
0x12 Unknown [2 bytes]
0x14 index Count [4 bytes] - I'm not sure
Size = 0x18

Straight after this comes [Pointer Count] entries like this

0x0 Index Pointer [4 bytes] - Pointer to a data block
0x4 Table Pointer [4 bytes] - Pointer to another Table of indexes
0x8 Index Count [4 bytes] - Not sure. If non-zero [Table Pointer]
has more indexes?
Size = 0x0C

These [Index Pointer] items point to offsets in the file which are
data items. At present Emails and Folders have been worked on.

Item Header:
0x0 Self [4 bytes] - current offset
0x4 Size [4 bytes] - size of block that follows
0x8 Unknown [2 bytes]
0xA Count [1 byte] - number of items in the block before the data
starts
0xB Unknown [1 byte]
Size = 0x0C

Then comes [Count] number of items:
0x0 type [1 byte] - specifies what the data is
0x1 value [3 bytes] - actual data

The following types have been found for Emails
Type - Value
0x02 -
0x04 - buffer pointer to file offset of email data
0x05 - buffer pointer to asciiz string containing the subject of email
0x06 -
0x07 - buffer pointer to asciiz message id of email
0x08 - buffer pointer to asciiz another string containing the subject of
email
0x09 -
0x0B -
0x0A - buffer pointer to asciiz message ids of parent emails
0x0C -
0x0D - buffer pointer to asciiz Name of sender
0x0E - buffer pointer to asciiz Email address of sender
0x11 -
0x12 -
0x13 - buffer pointer to asciiz Name of recipient
0x14 - buffer pointer to asciiz Email address of recipient
0x1A -
0x1B -
0x1C -
0x80 - Numeric ID (numeric)
0x81 -
0x84 - file offset to email data
0x90 -
0x91 -

The following have been discovered for Folder Items
Type - Value
0x01 -
0x02 - Buffer Pointer to Descriptive name of Folder
0x03 - Buffer Pointer to Filename of Folder
0x05 -
0x06 -
0x80 - Folder's ID (numeric)
0x81 - Folder ID of parent (numeric)
0x86 -
0x87 -
0x8A -

When handling blocks of data (as in Emails) the offset pointer will
point to the following structure:

0x0 Self [4 bytes] - current offset
0x4 Size [4 bytes] - size of block
0x8 Data Size [2 bytes] - size of data inside block
0xA Item Count [1 byte] - number of int size objects before data
0xB Unknown [1 byte]
0xC Next address [4 bytes] - File offset of next data block
Size = 0X10

Last Article:
Client/Server Socket class

Re: Outlook Express data format

Mike_Beard26-Jun-02 10:05

Mike_Beard

26-Jun-02 10:05

Wow!!! That looks like fun.

Thanks for the response. I think you've given me enough to think about as to whether I want to continue on with this or to try and find a program that does what I need (or at least close to what I need).

At least now, if I look at one of the files, I should have a better idea of what is going on.

Thanks again!

Cryptic Error popup

Jerry Wang26-Jun-02 7:56

Jerry Wang

26-Jun-02 7:56

Hi All,

Has anyone encountered:
An unnamed file was not found

error message box popup in your application before?

It happens when I run the release version of my MFC program outside of MS Visual Studio. When run inside visual studio, both debug and release versions have no errors...

Comments? Inputs?

Thanks.

Re: Cryptic Error popup

Ramu Pulipati26-Jun-02 8:20

Ramu Pulipati

26-Jun-02 8:20

This is MFC framework error message.

This will be occur when you try to open a file which doesnt exist physically.

If this problem occurs in InitInstance()..then manually populate the
CCommandLineInfo Object.

For more info, let us know what u r doing!

Hth,
Ramu

Re: Cryptic Error popup

Jerry Wang26-Jun-02 9:25

Jerry Wang

26-Jun-02 9:25

Thanks You for your help!

Thanks to your note, I found the problem in one of my destructors. It was attempting to delete a file that does not exist.

<br />
	CFileStatus	fileStatus;<br />
	// and get file status and test if the file exists<br />
	CFile::GetStatus("temp.satdef", fileStatus);<br />
<br />
<br />
	// m_attribute	==	0xCC if does not exist<br />
	//				+	0x10 if it's a directory<br />
	//				-	0x04 if it's a system file<br />
	//				-	0x08 if it's a volume<br />
	//			===============================<br />
	//			    ==	0xD0 if it does not exist or if it's a directory<br />
<br />
	if (!(fileStatus.m_attribute & 0xD0))<br />
		CFile::Remove("temp.satdef");<br />

Apparently, somehow, my fileStatus check sometimes doesn't work all the time.

STL ?

Rage26-Jun-02 7:38

Rage

26-Jun-02 7:38

Can anyone decode this piece of code for me ??

template <typename Type>
std::list<const bla*> * blou::bli() 
{
  return getObjectDescriptor().template listSonsOfType<Type>( );
}

I think there must be some STL (which i do not know at all) in the thing, but i quite do not understand the last line : what´s this .template ? and what is here really returned ? is this a cast or something ??

~RaGE();

Re: STL ?

Joaquín M López Muñoz26-Jun-02 8:33

Joaquín M López Muñoz

26-Jun-02 8:33

Well, this a rather obscure use of the template keyword caused by the extremely clumsy C++ syntax. getObjectDescriptor() returns an object of some class for which a template member function listSonsOfType is defined as in this example:

class CObjectDescriptor
{
...
template <typename T> std::list<const bla *> * listSonsOfType();
...
};

Now the line (without the template keyword)

return getObjectDescriptor().listSonsOfType<Type>( );

could be interpreted as a call to the member function or as an expression involving the operators "less than" and "greater than". In this case, the latter doesn't have any meaning, but C++ gurus found pathological examples in which both interpretations are valid. To disambiguate, one must include template.
By the way, this piece of code won't even approach to compile in VC++, which lacks template member function support.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: STL ?

Rage26-Jun-02 21:48

Rage

26-Jun-02 21:48

OK. Thank you very much.

~RaGE();

Can you use a template class member variable within a template class?

26-Jun-02 6:56

Can someone explain why the following doesn't compile:

#include < list >

template < class TYPE > class CNeighbourhoodArray
{
	CNeighbourhoodArray()
	{};
	~CNeighbourhoodArray()
	{};

	list < int > foo_list;
};

Is it illegal in C++ to use a template class as the type of a member variable of another template class? Did that make sense ? Wink | ;)

TIA,

Pete

Re: Can you use a template class member variable within a template class?

C^hris L^osinger26-Jun-02 7:04

C^hris L^osinger

26-Jun-02 7:04

Anonymous wrote:
Can someone explain why the following doesn't compile

what error do you get?

-c

Garbage collection, making life better - for weenies!

Image Processing - now with extra cess.

Re: Can you use a template class member variable within a template class?

26-Jun-02 7:05

Sorry, I forgot to include the error...

c:\pete\capture\vss\neighbourhoodarray.h(25) : error C2143: syntax error : missing ';' before '<'
c:\pete\capture\vss\neighbourhoodarray.h(26) : see reference to class template instantiation 'CNeighbourhoodArray<type>' being compiled

HTH,
Pete

Re: Can you use a template class member variable within a template class?

Joaquín M López Muñoz26-Jun-02 7:05

Joaquín M López Muñoz

26-Jun-02 7:05

This is perfectly legal, the only missing thing is the std:: prefix:

include < list >
template < class TYPE > class CNeighbourhoodArray
{
	CNeighbourhoodArray()	{};
	~CNeighbourhoodArray()	{};
	std::list < int > foo_list;
};

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: Can you use a template class member variable within a template class?

26-Jun-02 7:06

Doh! That'll do it.

Thanks a lot Joaquin

Re: Can you use a template class member variable within a template class?

Brian Delahunty26-Jun-02 7:19

Brian Delahunty

26-Jun-02 7:19

Have you checked your namespaces???

"When a friend hurts us, we should write it down in the sand, where the winds of forgiveness get in charge of erasing it away, and when something great happens, we should engrave it in the stone of the memory of the heart, where no wind can erase it" Nish on life [methinks]

"It's The Soapbox; topics are optional" Shog ⁹

Socket in non-blocking mode

26-Jun-02 6:38

Suppose we are making simple client server application.
We use a function "connect()" in client source code to connect to the server. By default this function is in blocking mode. As such when we try to connect, the program sticks at a particular location and only when this function returns, the program flow continues. This function return 0 on success.
Let suppose, the socket is in non-blocking mode, as such when we use connect(), the program flow not stop as this function immediately return and our application is free to do something else. In this case the connect() function immediately returns with error something like, WSAERRWOUILDBLOCK.

Now the problem is that how we will be able to know after some time that the connection actually established or not ??
Infact in blocking mode connect() waits for a while and returns 0 on success. But in non blocking mode connect() immediately returns and does its working on background. So how we will be able to know whether connect() established connection or not ???

Re: Socket in non-blocking mode

Joaquín M López Muñoz26-Jun-02 7:07

Joaquín M López Muñoz

26-Jun-02 7:07

Have a look at select.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: Socket in non-blocking mode

valikac26-Jun-02 7:09

valikac

26-Jun-02 7:09

By default, the program is in blocking mode when you use WSAConnect, connect, WSADisconnect, disconnect, etc. To be in non-blocking mode, you have to decide what non-blocking mode you want to use. There are numerous mode including WSAAsyncSelect, WSAAsyncEvent, and more complicated non-blocking mode for big servers. Once you have implemented a non-blocking mode, your network flow automatically becomes non-blocking.

For example, for a small network program such as an ftp client, chat/message program, etc. you can use WSAAsyncSelect. WSAAsyncSelect makes good use the the Windows messaging system. Once you have implemented WSAAsyncSelect, Windows sends you messaged including FD_CONNECT, FD_READ, FD_WRITE, FD_CLOSE, etc. You use the messages to determine what is going on with the network connection.

I highly recommend Network Programming for Microsoft Windows, Second Edition
by Anthony Jones and Jim Ohmund for Windows programmers.

Kuphryn

Database ( table Update/Delete)

26-Jun-02 6:15

I am using ODBC to acess Mysql DB ..

I am using comands MoveNext(), MovePrev() ... of Recordset class ..

it´s working well .. The AddNew register is working .. but when I try
to use Delete function or Update function appear the follow message:
No Cursos name avaliable ..

To Update I am using this code:

m_pSet->Edit();
m_pSet->m_id = NEW_VALUE;
m_pSet->m_descricao = NEW_VALUE;
m_pSet->Update();

to Delete I am using:

m_pSet->Delete();

Tks

Re: Database ( table Update/Delete)

Ramu Pulipati26-Jun-02 8:30

Ramu Pulipati

26-Jun-02 8:30

Are you opening the RecordSet Connection over 'CRecordset::dynamic'????

Thanks,
Ramu

ON_UPDATE_COMMAND_UI and CDialog's

Sprudling26-Jun-02 6:11

Sprudling

26-Jun-02 6:11

I have an MFC dialog based app, and ON_UPDATE_COMMAND_UI just doesn't work. For some reason ON_UPDATE_COMMAND_UI is sent when I actually choose the menu-option (Rather when the menu drops down). After asking around and searching the net it seems like this is a known problem, but I haven't been able to find any good info on why and/or how to make it work.

Is there someone here who can?

Sprudling Wink | ;)

Re: ON_UPDATE_COMMAND_UI and CDialog's

udayGovekar26-Jun-02 6:42

udayGovekar

26-Jun-02 6:42

Hi,

For your first question,

Suppose at run time you want to change(enable/disable,show/hide) the menuitems, then this function is usefull.

Second,

It works quite similar to other functions. You just have to add this function and write ur logic.

Re: ON_UPDATE_COMMAND_UI and CDialog's

Ernest Laurentin26-Jun-02 8:41

Ernest Laurentin

26-Jun-02 8:41

One way to do this is to loop through all items once the popup menu is drop down and call
CCmdUI::DoUpdate for all the child sub-menu. You will have to catch WM_MENUSELECT and loop through the sub-menu. Good luck!

Last Article:
Client/Server Socket class

Re: ON_UPDATE_COMMAND_UI and CDialog's

Sprudling26-Jun-02 22:20

Sprudling

26-Jun-02 22:20

Thank you VERY much Rose | [Rose]

This actually solves it quite elegant Suspicious | :suss:

I like that Big Grin | :-D

Sprudling

Array to.bmp file

Knowledge Seeker26-Jun-02 6:06

Knowledge Seeker

26-Jun-02 6:06

I have colors of a picture in array but i have to save all these colors i.e. picture into a .bmp file , I have already created .bmp file now how can I save my desired array's data into .bmp file at my desired x, y, places.

I'll me so thankfull to you.

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