C / C++ / MFC

David Crow3-Mar-06 6:38

3-Mar-06 6:38

johni__boy wrote:
Can anybody help me please to find out the bugs in the folowing code . The code doesnt contain any syntax errors but still it doesnt run .

It would be more appropriate if you found the problematic code (i.e., bug), and then ask us what is wrong with it. Asking us to search through a bunch of code to find out what is wrong is not what we (most of us at least) are here for. Narrow your code down to just a few statements and you'll get way more help. Smile | :)

For starters, calling findnumber() with NULL as the second argument will result in a problem when you go to dereference the pointer. The code you have to add a new number to the list is wrong.

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

johni__boy3-Mar-06 13:30

johni__boy

3-Mar-06 13:30

thanks for your comments, probably you are right.
The second argument by calling findnumber() is not Null but it is used to access to the structure :
typedef struct entry
{
int number; // our entry
int freq; // how often we've seen it

struct entry *next; // pointer to the next item
} entry_t;

I don't understand how is the second line of the input text is loaded in the buffer and what number we are adding to the list.

IdUnknown3-Mar-06 17:56

IdUnknown

3-Mar-06 17:56

johni__boy wrote:
The second argument by calling findnumber() is not Null but it is used to access to the structure :

Initially you set entrylist = NULL; so the first time you call the findnumber function the second argument is NULL. So in the findnumber function you should first check to see if the second argument named "list" is NULL, and if it is, you should return NULL.

Now, look at the last two lines of this block and imagine adding the first node into an empty list.

else
{
// no, create new one.
entry = (entry_t*)malloc(sizeof(entry_t));
entry->freq = 1;
entry->number = number;
entry->next = entrylist;
entrylist = entry->next;
}

1. again, initially entrylist is NULL
2. you create a memory block to hold a node and the next pointer is pointing to entrylist which is NULL. ok
3. entrylist should point to entry not entry->next.

I don't know if there are other problems, but that's what I see without compiling the code. You should learn to use breakpoint, the stack trace, and the watch window because these problems can be easily spotted.

basementman3-Mar-06 7:24

basementman

3-Mar-06 7:24

looks like homework to me.... Sleepy | :zzz:

onwards and upwards...

Problem with registering ITTAPIEventNotification interface

Stephen Hewitt3-Mar-06 20:19

Stephen Hewitt

3-Mar-06 20:19

Why make a linked list manually? Use a std::list and your bugs disappear and the program shrinks down to a handful of lines. Unless of course it's a learning exercise or even (gasp) homework.

Steve

bisvl3-Mar-06 5:57

bisvl

3-Mar-06 5:57

I need to register IITAPIEventNotification interface in order to proces events. For that I need a callnot.h and callnot.cpp files, but I don't have them. How can I get them?

How do make a FormView without Doc/View

Jethro633-Mar-06 5:49

3-Mar-06 5:49

Greetings:

I am trying to experiment with making an application with flexible windows that show different things and can be opened and closed at will and in no particular order. I do not want to involve the document / view architecture. There's no need for an underlying document; my program receives input data from external ports of various kinds.

For openers, I tried to create an SDI application with no Doc/View but whose client is a CFormView, not a CChildView. Why is this hard?

Should I REPLACE the CChildView client window with a CFormView? Or, should I create a CFormView and then derive the CChildView from the new CFormView (instead of from CWnd as the App Lizard would have it)?

I have a metric tonne of books on the subject of programming in MFC and I have yet to encounter one, just ONE, that clearly explains and lays out the architecture of SDI, MDI, Doc/View, non-Doc/View, splitters, CMainFrame, Views, etc, etc. I would like to understand these things in such a way that I can finally feel that I have some measure of control and choice as to how my application windows behave and can write a program that breaks from the straight jacket that is the MFC App-Lizard. Has anyone out there encountered a book or resource that does this? I mean, explain it to me like I'm 4 years old! Insult my intelligence! Just make it clear!

There, I feel better. Thanks in advance to anyone who responds.
Cheers,
Mark

David Crow3-Mar-06 6:07

3-Mar-06 6:07

Jethro63 wrote:
my program receives input data from external ports of various kinds.

Why would this preclude the use of Doc/View?

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Jethro633-Mar-06 7:15

3-Mar-06 7:15

Hi David:
It doesn't necessarily, but MUST I always use Doc/View? I find that I create my application using doc/view and the "doc" component of it goes unused. Then I find it just gets in my way when I want to do something like replace one view with another, or add a new view.

Its the principle of the thing really. Can't you just put up a main frame and then throw up whatever child windows you want, when you want without having to deal with all this doc/view baggage?

Thank for your response.
Mark

David Crow3-Mar-06 7:20

3-Mar-06 7:20

Jethro63 wrote:
Then I find it just gets in my way when I want to do something like replace one view with another, or add a new view.

In this situation, what is the view displaying?

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Jethro633-Mar-06 8:36

3-Mar-06 8:36

Could be anything. Let's say I'm connected to a specialized piece of equipment and it is sending messages asynchronously through the USB port to my application. I want to offer my user 3 or 4 different ways of viewing these incoming messages: raw hex data, a scrolling list view, a graphical histogram plot, a statistcial listing. The user should be free to open, close and arrange any number and combination of these windows. At the same time, maybe I would like a "Console Window" where the user enters synchronous commands and the response from the device is displayed in the same window. Still another window (like a form view) that contains push button controls, sliders, edit boxes that handle other types of commands to the device or to the application to control its behavior. I might also want the option to turn on a diagnostics window where special program messages get directed to.

I see that all of these windows involve data and I suppose that you could make it fit into the doc/view paradigm if you had a crow-bar and a sledge hammer, but I don't see how it helps me to use a doc/view based approach. I don't use serialization, I am used to saving data in files using old-fashioned read and write commands to an open file pointer. In the end, I always find that the doc/view needs a doc/view template and then I can never figure out how to open up more than one view for the same document data or create an alternate doc/view pair and it all gets way too complicated way too fast.

That's my story. Any suggestions would be welcomed.
Mark

Office Lineman3-Mar-06 14:07

Office Lineman

3-Mar-06 14:07

This is a method for creating an MFC CFormView application with no document--and the form window is not to be resized. If you don't mind the window being resized, don't do the frame/maximize box step. Sorry about the formatting, but it's from a Word doc, and I'm too lazy to clean up Word 2K's crummy HTML output Laugh | :laugh:

1. Create a new MFC AppWizard (exe) project.
	a. MFC AppWizard - Step 1 of 6
		i. Select "Single document" for the application type.
		ii. Uncheck "Document/View architecture support?".
	b. MFC AppWizard - Step 2 of 6 - no changes
	c. MFC AppWizard - Step 3 of 6 - no changes
	d. MFC AppWizard - Step 4 of 6
		i. Set the number of files on the recent file list to 0. (optional - no MRU anyway)
		ii. Press "Advanced..."
			1. Uncheck "Thick frame" and "Maximize box", leaving only "Minimize box" and "System menu" checked. (optional)
	e. MFC AppWizard - Step 5 of 6 - no changes
	f. MFC AppWizard - Step 6 of 6 - no changes
2. Create a CFormView for the application.
	a. Select Insert->New Form....
	b. Enter a form class name in the "Name" field, e.g. "CMyFormView".
	c. Press OK.
	d. Design the form as desired.
3. Adjust command handlers in new CFormView-based class.
	a. Using the ClassWizard, insert a handler for OnInitialUpdate.
	b. Add the following code into the OnInitialUpdate handler where indicated:
		GetParentFrame()->RecalcLayout();
		ResizeParentToFit();
4. Remove ChildView.h and ChildView.cpp from the project.  Delete the files.
5. Remove CChildView references from MainFrm.h
	a. Remove the "#include ChildView.h" directive.
	b. Remove the "CChildView m_wndView" member.
6. Adjust command handlers in MainFrm.cpp
	a. Remove the OnCmdMsg handler and delete its code.
	b. Remove the OnSetFocus handler and delete its code.
	c. Edit the OnCreate handler
		i. Remove the view creation code:
			// create a view to occupy the client area of the frame
			if (!m_wndView.Create(NULL, NULL, AFX_WS_DEFAULT_VIEW, CRect(0, 0, 0, 0), this, AFX_IDW_PANE_FIRST, NULL))
			{
				TRACE0("Failed to create view window\n");
				return -1;
			}
		ii. Remove the docking capability for the toolbar by commenting out or deleting the indicated lines. (optional)
7. Adjust application creation in <appname>.cpp
	a. Include the view class header, e.g. "#include "MyFormView.h".
	b. Edit the InitInstance function
		i. Replace the frame loading code:
				pFrame->LoadFrame(IDR_MAINFRAME, WS_OVERLAPPEDWINDOW | FWS_ADDTOTITLE, NULL, NULL);
			with the following code:
				CCreateContext oCreateContext;
				oCreateContext.m_pNewViewClass = RUNTIME_CLASS(CMyFormView);
				oCreateContext.m_pCurrentFrame = pFrame;
				pFrame->LoadFrame(IDR_MAINFRAME, WS_OVERLAPPEDWINDOW, NULL, &oCreateContext);
				pFrame->InitialUpdateFrame(NULL, TRUE);

Everything should compile okay.  N.B. when you run the application in debug mode, you will receive "Warning: Creating a pane with no CDocument." in the debug output.  It's a nice warning, but that WAS kind of the whole point, right?

--
I've killed again, haven't I?

Jethro6328-Dec-06 5:05

28-Dec-06 5:05

Hi "Office Lineman":

I lost track of this thread and did not discover your response until today. Thank you very much for your instructions. I normally respond right away when somebody takes the time to answer a question that I post, so I feel a bit embarrased that I missed this, especially since it is clear that you spent some time on this response.

I followed your instructions and they worked exactly as I had hoped. I was a bit puzzled by the final segment where the "CCreateContext" structure is brought in. After reading up on this structure, I see that most of its fields can be regarded as optional. This has lead me to an example on the MSDN DVD called "VIEWEX" which expands more on the problem that I originally pointed out: It is not obvious or straight forward how to create an application that consists simply of a main frame which can house a variety of different views, opened or closed in no particular order. I have been searching for a general understanding of all of this and it is difficult to get the answers I am looking for.

Anyway, thanks again for your instructions.
Mark

permutations19-Apr-10 13:07

permutations

19-Apr-10 13:07

This is absolutely awesome. Thank you so much for posting this! I've been going crazy trying to figure it out.

Re: What is IsolatedStorage

Rez_Spain6-May-10 23:07

Rez_Spain

6-May-10 23:07

Man, Maybe this topic is old as f*** but im just so grateful.
THANKS Office Lineman!

What is IsolatedStorage

Chintoo7233-Mar-06 5:47

Chintoo723

3-Mar-06 5:47

Does anyone know what is IsolatedStorage? I have this directory that I am unable to delete:
C:\Documents and Settings\<user>\Local Settings\Application Data\IsolatedStorage\1cz2yllv.kcp\v44qcfut.b25
\Url.b01cm1a5pqdgmvysoo2gnkbuohme03bk\Url.b01cm1a5pqdgmvysoo2gnkbuohme03bk\Files

Is there any way to remove this IsolatedStorage folder?

thanks!

Chintoo7233-Mar-06 5:58

Chintoo723

3-Mar-06 5:58

OK, this link http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemioisolatedstorageisolatedstoragefileclasstopic.asp[^] provides an example to remove the Isolted Storage files. I can use the C++ code, but it seems to require .Net framework. I have only Visual Studio 6 with platform SDK. I dont want to install .NET, does IsolatedStorage have an API outside .NET?

thanks!

copying an array of bytes to another array

chaitanya223-Mar-06 5:24

chaitanya22

3-Mar-06 5:24

copying an array of bytes to another byte array of same size

-- modified at 11:24 Friday 3rd March, 2006

Re: copying an array of bytes to another array

RChin3-Mar-06 5:30

RChin

3-Mar-06 5:30

...and your question is?

If I guess correctly, something like this would do nicely:

<br />
char pArray1[] = {1,2,3,4,5};  // Source array<br />
char pArray2[5];               // Destination array<br />
<br />
memcpy(pArray1, pArray2, 5);<br />

I Dream of Absolute Zero

Re: copying an array of bytes to another array

David Crow3-Mar-06 5:49