C / C++ / MFC

Re: Best way to set min size for a window?

22-Nov-05 9:04

Ian Bowler wrote:
What's the best (easiest) way to do this?

With CWnd::OnGetMinMaxInfo().

"Take only what you need and leave the land as you found it." - Native American Proverb

Ian Bowler22-Nov-05 10:57

Ian Bowler

22-Nov-05 10:57

Thanks! I'll look into that.

-Ian

Serialization and File | Save

BuckBrown22-Nov-05 7:49

BuckBrown

22-Nov-05 7:49

Hi,

I have an application that reads a data file and then diplays the information in myCdocument class. I have no need to save the document in serialized form. However, I accidentally clicked on the File | Save menu and discovered that my input data file (which contains very important data I don't want to change) gets erased to zero bytes effectively destroying my original data. How do I turn off the ability of the built in File | Save or otherwise preserve my data file? Do I need to write the data back out? I read the data in using the older FILE declaration because the CFile class was more problems than it was worth.

Buck

David Crow22-Nov-05 7:53

22-Nov-05 7:53

You need to modify the toolbar and File menu so that Save is no longer available.

"Take only what you need and leave the land as you found it." - Native American Proverb

BlackDice23-Nov-05 11:20

BlackDice

23-Nov-05 11:20

or just override the parent method with no code in it and don't call the base class's Save().

My articles

BlackDice

David Crow25-Nov-05 14:03

25-Nov-05 14:03

The only problem with this approach is that by leaving the Save option intact, it gives the user a false sense of functionality.

"Take only what you need and leave the land as you found it." - Native American Proverb

Cliff Hatch24-Nov-05 23:39

Cliff Hatch

24-Nov-05 23:39

Hi Buck

I happened to be doing something similar last week. I wanted to retrieve files produced by another application and had no need to read or write in serialized form. This doesn't exactly answer the question you asked, but I thought it might be of interest.

I obtained a file pointer from the CArchive object and did an ordinary read (in my case retrieving the contents of a text file as a single string). I didn't get any sense of the CFile class being more trouble than it was worth, because it was already there by default.

I gave the document class variables to accept the string and its length:

char* m_ps;  //Pointer to a string containing the whole text file contents<br />
ULONGLONG m_FileLength;

and I edited the Serialize function as follows:

void COstructDoc::Serialize(CArchive& ar)<br />
{<br />
	if (ar.IsStoring())<br />
	{<br />
		//Ostruct doesn't save files<br />
	}<br />
	else<br />
	{<br />
		//Read an RTO+ xdd file<br />
		CFile* fp;<br />
<br />
		fp = ar.GetFile();<br />
		m_FileLength = fp->GetLength();<br />
<br />
		m_ps = new char[(size_t)m_FileLength];	//create buffer for file contents, remember to delete in destructor<br />
<br />
		fp->Read(m_ps, (UINT)m_FileLength);<br />
	}<br />
}

The File | Open button works normally, and File | Save does nothing because there are no writes specified, but, if you wanted to write data back out again, this would be the place to do it.

I'm not sure why File | Save destroyed your data. The Serialize function would have done nothing by default. Did you alter the if (ar.IsStoring()) layout?

Best Regards

Cliff Hatch

-- modified at 6:02 Friday 25th November, 2005

Web page segmentation

llp00na22-Nov-05 7:20

llp00na

22-Nov-05 7:20

Dear All

I am using a webBrowser control as part of my project which i am developing. After loading a web page within a dialog box, I am interested in segmenting the current web page into coherent blocks (for example: images, tables, lists). I have tried detecting collections of html elements (images, paragraphs, divs...) by retrieving them from an instance of the html document.

Now, i am not sure if its the right method to segment a web page. Because i will end up specifying (hard coding) which elements to detect (anchors (a), divs, tablerows (tr), tabledata(td), unordered lists (ul)... and so forth)

detecting such elements and storing them in blocks will create redundancy. for example may contain anchors . detecting each seperately will result in blocks within blocks !!!

Does any body have a good idea for implementing the segmentation. I hope i have put it forward and not confused you guys.

Your views will be very much appreciated

llp00na

-- modified at 13:26 Tuesday 22nd November, 2005

SHFileOperation problem

Alex Orovetskiy22-Nov-05 6:05

22-Nov-05 6:05

I've got a serious problem with SHFileOperation which, in short, disallow me to use it for copying files (I haven't tried it on deleting\moving\something else). The code below is showing the way I am using it.

<br />
CString szTo(theApp.m_szMwDir), szFrom(theApp.m_szOoTDir);<br />
szTo += "\\Data Files\\\0\0";<br />
szFrom += "\\*.*\0";<br />
SHFILEOPSTRUCT fos;<br />
fos.hwnd = m_hWnd;<br />
fos.pFrom = szFrom;<br />
fos.pTo = szTo;<br />
fos.wFunc = FO_COPY;<br />
fos.fFlags = FOF_NOCONFIRMMKDIR;<br />
fos.hNameMappings = NULL;<br />
fos.lpszProgressTitle = NULL;<br />
SHFileOperation(&fos);

The problem is that when I run the application it comes out with "Error, file not found" error generated by SHFileOperation. theApp.m_szOoTDir is initialized correctly so it can't be a problem. Now let's get to the strange part. Let's assume that theApp.m_szOoTDir = "C:\TR_OoT_Test\Data Files" (it has this value in my test app so I'll use it for convenience). I want to copy all files in it and its subdirs to the destination directory (around 1000 in total) hence the wildcards. So, as I've already told, the application comes out with an error that the file cannot be found. But if I will create a char array and hardcode the path into application...it works. The path is the same:

CString szTo(theApp.m_szMwDir);<br />
szTo += "\\Data Files\\\0\0";<br />
char szFrom[] = "C:\\TR_OoT_Test\\Data Files\\*.*\0\0";<br />
SHFILEOPSTRUCT fos;<br />
fos.hwnd = m_hWnd;<br />
fos.pFrom = szFrom;<br />
fos.pTo = szTo;<br />
fos.wFunc = FO_COPY;<br />
fos.fFlags = FOF_NOCONFIRMMKDIR;<br />
fos.hNameMappings = NULL;<br />
fos.lpszProgressTitle = NULL;<br />
SHFileOperation(&fos);

If I will dynamically create char array by copying, concatenating, converting from CString or any other ways it stops working. So in short it works only with path written down when I am initializing an array or pointer to char string and ONLY to char string. I am absolutly clueless why it is so and how to overcome it. I was trying different workarounds for a few days and came up with nothing. In short - I am desperate. Any input is really appreciated.

Thank you for you time.

C^hris L^osinger22-Nov-05 6:32

22-Nov-05 6:32

Alex Orovetskiy wrote:
If I will dynamically create char array by copying, concatenating, converting from CString or any other ways it stops working

CString probably doesn't store multiple "\0"s at the end of the string. the first one terminates the string while you're concatenating, so it doesn't bother storing anything past that.

Cleek | Image Toolkits | Thumbnail maker

David Crow22-Nov-05 8:09

22-Nov-05 8:09

Chris' observation is correct. To remedy this, I suggest using this class from Michael Dunn. It takes care of those \0 oddities!

"Take only what you need and leave the land as you found it." - Native American Proverb

Alex Orovetskiy22-Nov-05 8:23

22-Nov-05 8:23

Actually CString does handle multiple \0. Otherwise it won't work for pTo field of the structure. And even if it doesn't it still doesn't explain the fact why if I convert CString to char[] (using the way described in MSDN aka using strcpy) and add a \0 to the end it still doesn't work. Oh and I would really like to avoid using any wrapper classes. The project is already bloated (at least for the purpose it serves) and I don't want to bloat it any more.

C^hris L^osinger22-Nov-05 8:33

22-Nov-05 8:33

Alex Orovetskiy wrote:
Actually CString does handle multiple \0.

actually, it doesn't. when doing an assignment to a CString, it checks the length of the new (right hand side) string by scanning for the first \0. then it reallocs and memcpy's strlen bytes from the new string to the destination string. it will never scan past the first \0, never count anything past the \0 towards the new string length, never alloc space for anything past the \0, and never copy anything past the \0.

step into the CString assignment operator and watch.

CString test;
test = "A\0\0";
ASSERT(test.GetLength()==1);

CString isn't going to get you where you want to go.

Cleek | Image Toolkits | Thumbnail maker

-- modified at 15:07 Tuesday 22nd November, 2005

Alex Orovetskiy22-Nov-05 9:03

22-Nov-05 9:03

Chris Losinger wrote:
CString isn't going to get you where you want to go.

OK...but why does it work for pTo field which also should be double-zero terminated ? Actually it working for pTo and not working for pFrom got me to beleive that it is not double-zero problem...

David Crow22-Nov-05 9:00

22-Nov-05 9:00

Alex Orovetskiy wrote:
Oh and I would really like to avoid using any wrapper classes.

Why?

Alex Orovetskiy wrote:
The project is already bloated (at least for the purpose it serves) and I don't want to bloat it any more.

Bloated? With data, possibly. With code, hardly ever. You are making the common mistake of assuming more code = more bloat. This is hardly ever the case, especially without any supporting metrics. Whether you put together the 30 lines of code to deal with SHFileOperation() and its nuances, or you use a class that wraps those same 30 lines of code, the net result is the same.

"Take only what you need and leave the land as you found it." - Native American Proverb

Alex Orovetskiy22-Nov-05 9:14

22-Nov-05 9:14

DavidCrow wrote:
Bloated? With data, possibly. With code, hardly ever. You are making the common mistake of assuming more code = more bloat.

Well yeah, I am making this assuption. I am basing it on one thing: when I'm not doing any coding on the project and than return only to spend around 10 mins figuring out what does what. But that's pretty much irrelevant to the subject.
Just tried the following (note that szFrom contains \*.*):

<br />
char buf[MAX_PATH];<br />
strcpy(buf,szFrom);<br />
strcat(buf,"\0");

It didn't work. I will try using the demo of that wrapper class to see if it comes out with the same results or no.

C^hris L^osinger22-Nov-05 9:27

22-Nov-05 9:27

Alex Orovetskiy wrote:
strcat(buf,"\0");

any of the string functions are going to recognize '\0' as an empty string and basically do nothing at all: "append nothing to a string? consider it done!".

try :

buf[szFrom.GetLength() + 1] = 0;

Cleek | Image Toolkits | Thumbnail maker

-- modified at 15:35 Tuesday 22nd November, 2005

Alex Orovetskiy22-Nov-05 9:43

22-Nov-05 9:43

If I knew how to build statues I would have built one for you. It works. It perfectly works. No words can express my gratitude. Thank you !

P.S. And like always the solution was really simple. I remember putting a wrong comma once...

C^hris L^osinger22-Nov-05 9:51

22-Nov-05 9:51

Alex Orovetskiy wrote:
Thank you

you're welcome.

come again soon, we're open 24/7.

Cleek | Image Toolkits | Thumbnail maker

David Crow22-Nov-05 9:38

22-Nov-05 9:38

Alex Orovetskiy wrote:
It didn't work.

What do you mean by "It didn't work?" After strcpy() returns, buf and szFrom should contain identical strings. Are you saying this is not the case?

Alex Orovetskiy wrote:
strcat(buf,"\0");

Given that strcat() operates on nul-terminated strings, this effectively does nothing. What were you expecting?

"Take only what you need and leave the land as you found it." - Native American Proverb

Alex Orovetskiy22-Nov-05 9:48

wince - ppc2003 - change network management defaults

22-Nov-05 9:48

DavidCrow wrote:
Given that strcat() operates on nul-terminated strings, this effectively does nothing. What were you expecting?

Expecting the wrong thing it seems Smile | :)

Actually I didn't think it would turn this way. Oh well...it is working now. Thank you guys for spending your time on me.

sdt2422-Nov-05 5:40

sdt24

22-Nov-05 5:40

Does anyone know please if it is possible to change the default settings of the internet and private network combo box settings on the Network Management screen programmatically using evc4. Currently Internet defaults to 'My ISP' private network defaults to 'My Work Network'. I need to default both to GPRS.
Any sample code gratefully received.
Smile | :)

-- modified at 17:39 Tuesday 22nd November, 2005

Handle to Menu

NYTSX22-Nov-05 4:45

NYTSX

22-Nov-05 4:45

Hi,

I have a dialog based app that basically has 3 dialogs. There is a main dialog that has a menu that allows the user to "bring up" the other two dialogs by selecting them from the menu. I was wondering how I could get the handle to the menu in my main dialog so that I could place a check mark next to the dialogs that are currently displayed.

I have code that does this, but it is from an MDI app and doesn't work for this dialog based app.

Here is a little bit of the code that I thought would work, but doesn't Frown | :(

<br />
// This code returns a 0 for GetParent()<br />
CMenu* pMainMenu = GetParent()->GetMenu();<br />
CMenu* pSub = pMainMenu->GetSubMenu(1);

Thanks in advance for your help.

Re: Handle to Menu

David Crow22-Nov-05 8:04