C / C++ / MFC Discussion Boards

vijayaramaraju21-Dec-04 16:47

21-Dec-04 16:47

Hi,
I'm trying to custom draw a list control. I'm also using it as a virtual list supplying data handling the LVN_GETDISPINFO message. I've handled the NM_CUSTOMDRAW to custom draw only specific Items the problem is the iSubItem variable in the LPNMLVCUSTOMDRAW structure is always zero Confused | :confused:

when I'm expecting it to change. I'm depending on it to idententify which item / subitem it is currently drawing. this I'm doing when dwDrawStage == CDDS_ITEMPREPAINT. am i doing something wrong here. I've seen a sample application XListCtrl in this site which seems to work. am i doing something wrong here. please give me directions as to how to resolve this problem. thanks in advance. Rose | [Rose]

can anybody provide a solution!

LiYS21-Dec-04 16:29

LiYS

21-Dec-04 16:29

I'm working on a filter funtion which filters the items in the list control. The items that I inserted into the list control have three attributes which is "creation time", "readed or not" and "item color"(because these attribute are specific to me, so I generalized them a little). what I'm trying to accomplish is to filter what appears in the list control according these three attribute of each item.
I'v got three comboboxs as the user interface which is according to the three attributes. They have the following content.

"creation time" combobox "readed or not" combobox "item color"
->today ->all ->red
->recent 3 days ->readed ->green
->recent week ->not readed ->black
->recent month
->all time

I am not famaliar with algorithm, but I am sure with algorithm I can come up with a very concise and clear flitering logic.But now I just trying to solve the problem too;)!
Can anybody provide a pseudo code or simple algorithm?
thanks!

Re: can anybody provide a solution!

David Crow22-Dec-04 3:35

David Crow

22-Dec-04 3:35

Here is a generalization:

PopulateListControl()
{
    date  = value from "creation time" combobox
    read  = value from "read or not" combobox
    color = value from "color" combobox
 
    for (int x = 0; x < number_of_items; x++)
    {
        if (item.date == date && item.read == read && item.color == color)
            insert item into list control
    }
}

Does this make sense?

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

How can save a drawing?

phanduchuynh21-Dec-04 16:14

phanduchuynh

21-Dec-04 16:14

I have ploted a figure in a static or edit or any region. But I do not know how to save it in .jpeg,.bmp...file. Please help me in this trouble! thank you very much! Smile | :)

apply not1 to predicates

RickyO21-Dec-04 14:10

RickyO

21-Dec-04 14:10

Hi there,

It's been years since I done serious C++ programming and I am rusty on STL and templates and I need a quick solution for the following issue:

I need to define some kind of policies based on user input, for instance:
- some processes should handle requests that start with letter 'A' - say
this is policy_1 (and is derived from unary_function<string, bool=""> ?!)
- the reminder of the processes should handle all the other requests -say
this is policy_2, which is the negation of policy_1-

The processes are stored in a vector, each process object has a reference
to its policy

References/pointers to policies are stored in a vector (so policy_1 and policy_2 have to be siblings from a common base class: unary_function<string, bool=""> ?!)

When a request is fired I need to:
- find appropriate policy in the policies vector
- in the processes vector find the least loaded process among those
which have a reference to the policy found in the previous step

So the question is how do I create a stand alone policy object that is the negation of policy_1 ?

Thanks,
Rick.

Kernel mode programming W2k

AhmedOsamaMoh21-Dec-04 11:24

AhmedOsamaMoh

21-Dec-04 11:24

I hope anyone can help me..

Do I have to learn how to write a windows driver(W2K) to make programs works in the kernel mode...

plz if u have any resources about the kernel mode programming ..infrom me and thx

bye Smile | :)

Re: Kernel mode programming W2k

naren-vc21-Dec-04 21:27

naren-vc

21-Dec-04 21:27

you can go through the book of undocumented windows 2000 secrets by sven b.schreiber. there are plenty of books available in the market. U better search in the net and buy the books that u like. you can search for the amazon.com for the book titles.

naren

Re: Kernel mode programming W2k

Henry miller22-Dec-04 3:29

Henry miller

22-Dec-04 3:29

Pretty much. There are tricks that might let admin into kernel mode, but other than device drivers you shouldn't need kernel mode. (if anyone other than admin can get into kernel mode it is a bug)

What are you trying to do? If you just want to learn kernel mode programing as windows does it, then your best bet is to get the kernel for reactos and hack on that. (or if you want a kernel that is more useable, linux/BSD)

ID_FILE_OPEN message

bitpusher21-Dec-04 10:52

bitpusher

21-Dec-04 10:52

Hello,

In my CWinApp() derived class, I tried to handle the ID_FILE_OPEN message (using VC++.net's properties pane, but putting a breakpoint in the code shows that it never goes there. What gives?

My intent is to use a different doc/view template than the first one on the list.

thanks,

JennyP

Crashes on Windows 98...

herbert_chow21-Dec-04 10:44

herbert_chow

21-Dec-04 10:44

Hi,

I have a program developed on Windows 2000 with the following properties:

1. It is an MFC Appwizard generated MDI application
2. Links to a COM server that I wrote
3. Links to 2 ActiveX Controls that I use for displaying graphics
4. Links to 2 dll's that basically have functions that communicate with the serial port
5. Is multi-threaded, I create my threads using the Win32 API ::CreateThread().

I have tested this program on Windows XP and Windows 2000 and it runs on these platforms without a hitch. However, when I use this program on Windows 98, my program crashes in many places. I deploy my program using Windows Installer so that my COM Server and ActiveX Controls are automatically registered for me, and on Win98 it seems that the program can successfully talk to the COM Server and use the ActiveX Controls.

I am wondering if anyone has experience developing applications that work with all of XP,2k and 98 and can tell me what would cause my program to crash on Win98? Will a re-compile with optimizations on a Windows 98 machine fix it? Or will it have no effect at all? I would also like to point out that the Windows 98 machine is slower and has less ram. Sometimes I get the out of hdd space warning too. Could this cause my program to crash?

Thanks in advance!

Re: Crashes on Windows 98...

Michael Dunn21-Dec-04 14:37

Michael Dunn

21-Dec-04 14:37

Things that come to mind from your description:
* Don't use CreateThread() to create threads, use AfxBeginThread() if the thread contains MFC code, or _beginthreadex() otherwise.
* Make sure your graphics drawing code cleans up GDI objects properly everywhere. Win 9x has 16-bit limitations in GDI, it's very easy to exhaust an internal 64K heap if you leak GDI objects (pens, brushes, etc).
* Does your serial port code work on 9x in the first place? Hardware access is radically different between 9x and NT.

--Mike--
LINKS~! Ericahist | 1ClickPicGrabber | CP SearchBar v2.0.2 | C++ Forum FAQ | You Are Dumb

Re: Crashes on Windows 98...

herbert_chow21-Dec-04 15:35

herbert_chow

21-Dec-04 15:35

Thanks Michael, these are all very helpful hints that I have read about at many places but never followed because my code seemed to work in 2k Smile | :)

I guess I should really look into the docs more closely and then go over all my code that doesn't behave.

Most of my graphics drawing code is in my ActiveX controls. They do actually store graphic objects to speed up draw times I guess that may be why its causing crashes.

I am using CreateFile and ReadFile functions to get at the serial port. I can't seem to find information about how hardware access is radically different between 9x and the newer 2k, but this will bump me in the right direction for further investigation.

Thanks again!

Cut & paste in FormView - pls help

h.lee21-Dec-04 9:19

h.lee

21-Dec-04 9:19

How can I enable the cut/copy/paste function in a "Form View"?

If I put a text box (edit control) in a dialog box with a MFC Dialog based application, the cut/paste functions work automatically with the Ctrl-X and Ctrl-V keys without any additional codes.

But if I were to do the same with a form view, i.e., using CFormView as the base class in a MFC SDI application, the cut/paste function is deactivated by default. How can I enable the functions?

Interestingly, I can get the functions to work simply by deleting all the associate accelerator keys. However, this is not the right approach as the menu functions remain grayed out.

Re: Cut & paste in FormView - pls help

BlackDice21-Dec-04 11:05

BlackDice

21-Dec-04 11:05

Under link below to 'my articles' see the 'lockable edit and combobox controls' article. The article is meant to demonstrate something else, but I also implement Ctrl+C,Ctrl+V functionality in the classes.

My articles

www.stillwaterexpress.com

BlackDice

Re: Cut & paste in FormView - pls help

h.lee21-Dec-04 13:51

h.lee

21-Dec-04 13:51

My understading of your approach is to derive a new class, CLockEdit, from CEdit and then use PreTranslateMessage to catch messages before the functions are executed. But is it necessary to create a new class just for this?

All I wanted to do is to turn on the cut/copy/paste function that is already there. As I had mentioned, the function can be enabled simply by deleting the Ctrl+X/C/V accelerators. My guess is that since I did not build any event handler for the accelerators, default handlers are used, which turns the function on.

If my guess is correct, shouldn't I be able to enable the functions via accelerators or menu functions, without the need of a new edit class?

Re: Cut & paste in FormView - pls help

BlackDice22-Dec-04 2:47

BlackDice

22-Dec-04 2:47

h.lee wrote:
shouldn't I be able to enable the functions via accelerators or menu functions, without the need of a new edit class?

Probably so, but I don't know how, myself. This class I made was mainly to let edit controls be disabled without being grayed out. I was just trying to provide any help I could.

My articles

www.stillwaterexpress.com

BlackDice

Re: Cut & paste in FormView - pls help

h.lee22-Dec-04 5:08

h.lee

22-Dec-04 5:08

Thanks for the help. As a newbie I really appreciate any help I can get. One day hopefully I can be like you and a bunch of others in this forum to offer helps to others.

For now, someone please help!

DrawDragRect color inverse?

Anonymous21-Dec-04 9:12

Anonymous

21-Dec-04 9:12

CBrush brush;
brush.CreateSolidBrush(RGB(0,0,255)); // Blue
CRect rc = CRect(CPoint(100,0), CPoint(200,100));

//Blue Rectangle
dc.SelectObject(&brush);
dc.Rectangle(CRect(CPoint(0,0), CPoint(100, 100)));

//Yellow Rectangle
dc.DrawDragRect(&rc, bdry, NULL, bdry, &brush, NULL);

Compiler does not update changed parameters

21-Dec-04 6:38

Hi,

I'm using Microsoft Visual Studio .Net 2003. I created a class and wrote a constructor that took three parameters:

int,
unsigned char,
int

Then, realizing that when declaring a class as a managed type (__gc) that I can't have unsigned data types, I went back to my constructor and I changed the data types to:

(Keep in mind, I declared all the appropriate #using <mscorlib.dll> #using <system.dll> using namespace System; etc)

System::Int32,
System::Byte,
System::Int32

I did a "Clean Solution" and then a Build Solution and yet, when I try to create an instance of my object:

ConsumptionManager * consumptionManager = new ConsumptionManager(1, 2, 3);

It still expects me to pass the old parameter data types. How can I get the compiler to pick up the new parameter data types?

Thanks

PPM

Zoom Excel Sheet with C++ and MFC application

Anonymous21-Dec-04 6:16

Anonymous

21-Dec-04 6:16

I am trying to zoom an excel sheet to 75% from C++, using visual studio .net 2003. I have an mfc application and have imported objects to access an excel sheet. I can zoom the printed version out to 75% but I can't get the magnification to 75%. Anyone know any way to to this?

Proving that CPU is "overloaded"

Brad Bruce21-Dec-04 4:46

Brad Bruce

21-Dec-04 4:46

I am working on a server application that spawns a new thread for each user request. Then the number of requests gets over 20 or so there is a noticable slowdown in performance. BUT!!! the CPU doesn't show a spike.

I am attributing this to having too many things going on at the same time (imagine printing from 20 applications at once) Does anyone know which of the many counters I can look at to show the true load?

The threads are spread over many processes, so no individual process is getting enough time to show up on the performance monitor.

MFC 6.0 SP5
IIS communicating with a "Master program" using winsock
Master program communicates with surrogates via windows messages (WM_COPYDATA...)

Thanks,
Brad Bruce

Re: Proving that CPU is "overloaded"

David Crow21-Dec-04 8:14

David Crow

21-Dec-04 8:14

One thing you might be able to do is look at the % Processor Time counter of the Idle instance. If you see this number drop, you know that the CPU is busy doing something else.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Re: Proving that CPU is "overloaded"

Henry miller21-Dec-04 9:36

Henry miller

21-Dec-04 9:36

Are you sure it is CPU? Perhaps your network is overloaded? Perhaps you are loading more data off the drive than it can transfer. At one time (back was a 486 was hot) this would commonly indicate you were out of memory and swapping (not so much an issue now, but it might be in your particular case).

My guess is network, get a good network card on a good switch. (Cheap gigabit ethernet cards often are barely faster than 100megabit in real world abilities)

In short, do not rule anything out. These days CPUs are rarely the bottleneck.

Re: Proving that CPU is "overloaded"

Brad Bruce21-Dec-04 14:36

Brad Bruce

21-Dec-04 14:36

Network was the first thing looked at (The experts say we're good there)

Tonight I was able to run one of the programs in isolation. It used 50% of the CPU by itself.

Common sense says that if you're running 4 instances of the same application you're using 200% of the CPU etc.

I was able to watch CPU time go up as these processes were running. Unfortunatly when it reaches a "breaking" point the CPU meter drops down to 12-15% utilization even with all of the processes running.

"I'm so confused!!!!" Confused | :confused:

Thanks for the input though (I might have to personally check the network tomorrow!!!!!)

Re: Proving that CPU is "overloaded"

Henry miller22-Dec-04 3:05

Henry miller

22-Dec-04 3:05

Well first you need to profile your code and see where and why it is taking so much CPU time. Often a small change can make a major difference. If you can get the amount of CPU you use down, that can mean a lot. If you can't get your CPU use down, you need to add more CPUs to the problem.

As for why you are seeing problems, I can only guess. Some things it could be:

Each time the OS switches processes you trash the CPU cahce, and it is taking that long to update because your processes aren't very cache friendly anyway. In this case if you can change how your look at data it might help. (ex: when looking at a 2d array perhaps you should loop on elements in a different order) This is a real problem, but it very complex.

Locks could easilly be a problem. The classic one thread grabs lock A, then lock B, while the other grabs lock B, then A - except it happens at the same time so both processes are hung waiting on the other. That you complete the tasks only suggests you have timeouts on your locks, so if you don't get a lock quickly you release all locks until you can get the others. This would explain your situation.

You said network was ruled out, but have you ruled out swaping? Maybe you just need to add more RAM.

If you are dealing with a database, hire an expert in that database to optimise your queries. You might be able to get some major improvements with some fancy work here.

My guess is that the code profiler will give you the most useful information.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.