C / C++ / MFC Discussion Boards

blade29-Sep-03 9:01

29-Sep-03 9:01

Is there a way to trap a mouse click on your taskbar window button.

My application does not have the title bar. So am facing two problems.

1. I cannot restore my application by clicking on the taskbar window button, if it is minimized.

2. On Windows 2000 if I choose Minimize All, my app is not minimized along with the other apps.

Help wanted badly!!!

Thanks,
Blade

Executing an EXE from memory

Larry Antram29-Sep-03 8:54

Larry Antram

29-Sep-03 8:54

I would like to execute an EXE from memory (instead of disk). Is this practical? If so, does anyone have any hints or suggestions as to how it can be accomplished?

Re: Executing an EXE from memory

David Crow29-Sep-03 11:14

David Crow

29-Sep-03 11:14

Yes. Search MSDN and the Net for the PE file format.

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Re: Executing an EXE from memory

Larry Antram29-Sep-03 12:23

Larry Antram

29-Sep-03 12:23

I undoubtably have horrible MSDN searching skills, however the most I gleaned from a massive article with way too much information I'm not interested in was:

"When PE files are loaded into memory via the Windows loader"... bla bla bla.

I'm just wondering if there is some relatively easy way (in the Win32/C++ world) to launch a PE from memory (instead of disk)?

From disk we have lots of API's... WinExec, CreateProcess, ShellExecute, etc.

What's the basic technique for launching from memory? Is assembly required? Confused | :confused:

I'm just basically looking for a tidbit of information to give me a headstart -- before having to comprehend all of the information about PE files and apparently the Windows loader and such.

Re: Executing an EXE from memory

Michael Dunn29-Sep-03 16:29

Michael Dunn

29-Sep-03 16:29

Larry Antram wrote:
I would like to execute an EXE from memory

No, because the PE loader uses memory-mapped files to move the EXE image into memory. This requires that the EXE be a real file on disk.

--Mike--
Ericahist | Homepage | RightClick-Encrypt | 1ClickPicGrabber
CP SearchBar v2.0.2 released

How to create an "Open With" list?

ralfoide29-Sep-03 8:45

ralfoide

29-Sep-03 8:45

Hi!

I need to be able to launch a viewer for a given file from my application (Win32/MFC/C++). Ideally I'd like to present the user with choices similar to the "Open With..." feature of the explorer shell.

I tried SHGetFileInfo but it keeps returning 0 for the flag SHGFI_TYPENAME (failure).

So I assume there's two part in my quest:
1- Find the type (mime type?) a given extension (I don't necessarily have the file created yet -- i.e. I'd like the user to be able to choose before creating the file)
2- Find a list of suitable applications (path, "user friendly" name) that can open that mime type.

I seems like I could just go and fish the info from the registry, but would that work on any windows version?

Regards
R/

Re: How to create an "Open With" list?

Amit Dey29-Sep-03 13:33

Amit Dey

29-Sep-03 13:33

ralfoide wrote:
I could just go and fish the info from the registry
seems like the only way. Blush | :O

Hush,hush...
thought I heard you call my name now.

Kula Shaker.

Amit Dey
Latest articles at CP -
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Easy question about formatting a string

NewHSKid29-Sep-03 8:18

NewHSKid

29-Sep-03 8:18

Hi everyone,

Just a quick question. Is there a way to display binary when formatting a string? I know %d is decimal, %X is hex....is there one that even exists for binary?

Jimmy

Just cause I am 15, doesn't mean I'm dumb! (I'll really be 4 on Feb. 29...the year 2004)

Re: Easy question about formatting a string

Ravi Bhavnani29-Sep-03 8:35

Ravi Bhavnani

29-Sep-03 8:35

There isn't a ready-made format specifier like %b that will format an integer in binary. You'll have to brew your own by walking the bits.

/ravi

Let's put "civil" back in "civilization"
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ravib@ravib.com

Re: Easy question about formatting a string

David Crow29-Sep-03 8:38

David Crow

29-Sep-03 8:38

NewHSKid wrote:
...is there one that even exists for binary?

No, you'll need to roll your own.

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Re: Easy question about formatting a string

WREY29-Sep-03 11:49

WREY

29-Sep-03 11:49

There are several ways. Here are a few.

The example below will display the binary representation for the decimal 100. In addition to '#including' <bitset>, you'll also have to '#include' <limits>

cout<<"\n 100: " <<bitset<numeric_limits<unsigned int>::digits>(100)<<endl;

the="" example="" below="" will="" also="" display="" the="" binary="" configuration="" for="" decimal="" 85.

cout<<"\n="" 85:="" "="" <<bitset<8="">::bitset(85) <<endl;

there are="" some="" subtle="" differences="" between="" the="" first="" example="" and="" second,="" but="" biggest="" is="" that="" in="" second="" you="" interested="" only="" having="" eight="" bits="" to="" represent="" value,="" whereas="" you'll="" get="" 32="" value.="" iow,="" can="" restrict="" number="" of="" want="" have="" representing="" value="" you're="" displaying.

here's="" one="" for="" letters.="" it="" will="" show="" binary="" representation="" letter="" 'a'="" using="" 8="" bits.

cout<<"\n="" \"a\":="" "="" <<bitset<8="">('A') <<endl;

lastly, here's="" one="" to="" show="" a="" string="" of="" letters="" (e.g.="" "abcd").

bitset<32=""> Ltrs = bitset<numeric_limits<unsigned int>::digits>('ABCD');
cout<<"\n \"ABCD\": " <

Valid Pointer ??

Shah Shehpori29-Sep-03 8:10

Shah Shehpori

29-Sep-03 8:10

Hi!

How can i determine that the pointer is pointing to a valid memory address??

e.g:

consider

class CTest
{
 public:
  
   void Release()
   {
     delete this;
   }
};

CTest *pTest = NULL

pTest = new CTest();

pTest->Release();

If you look at the last statement i.e pTest->Release();, the memory poionted by pTest is deleted, but pTest still contains some value. I want to determine whether the value in pTest is a valid address or not ? How can i do so ?

N.B, I've read somewhere that in MFC the is a function something like AfxIsValidAddress(), but i would prefer a non-mfc solution

Re: Valid Pointer ??

Ravi Bhavnani29-Sep-03 8:39

Ravi Bhavnani

29-Sep-03 8:39

You can use one of several Win32 APIs to check the validity of a pointer: IsBadCodePtr(), IsBadReadPtr(), IsBadStringPtr() and IsBadWritePtr() as well as the Huge analogs.

/ravi

Let's put "civil" back in "civilization"
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ravib@ravib.com

Re: Valid Pointer ??

David Crow29-Sep-03 8:53

David Crow

29-Sep-03 8:53

Unfortunately, AfxIsValidAddress() and related functions like IsBadReadPtr() don't tell you if the pointer has been freed or not. They know if the address can be read from and/or written to. You'll just need to get into the habit of assigning NULL to the pointer after delete has been called.

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Re: Valid Pointer ??

igor196029-Sep-03 13:06

igor1960

29-Sep-03 13:06

class CTest<br />
{ <br />
public:  <br />
   	CTest** m_ptr;<br />
	CTest(CTest** ptr = NULL)<br />
	{<br />
	 	m_ptr = ptr;<br />
	}<br />
	~CTest();<br />
	{<br />
           if(m_ptr)<br />
		*m_ptr = NULL;<br />
	}<br />
	void Release()   <br />
	{     <br />
		delete this;   <br />
	}<br />
};<br />
<br />
<br />
CTest *pTest = NULL<br />
pTest = new CTest(&pTest);<br />
pTest->Release();

"...Ability to type is not enough to become a Programmer. Unless you type in VB. But then again you have to type really fast..."
Me

Re: Valid Pointer ??

Michael Dunn29-Sep-03 16:33

Michael Dunn

29-Sep-03 16:33

Shah Shehpori wrote:
How can i determine that the pointer is pointing to a valid memory address??

There is a big difference between "valid memory" and "memory that contains valid data". Unfortunately the computer can only tell you about the former. Even after you delete a pointer, the memory is not usually removed from your app's process space, so you could go on dereferencing the pointer and not cause a GPF.
As someone else said, get in the habit of setting pointers to NULL after a delete or Release() call and you'll avoid such bugs.

--Mike--
Ericahist | Homepage | RightClick-Encrypt | 1ClickPicGrabber
CP SearchBar v2.0.2 released

Visual Assebmler

Stefak29-Sep-03 7:17

Stefak

29-Sep-03 7:17

Please help me to find some Assembler IDE which work on Win32.
(Kind of VASM).
I spend much time for surfing all over WWW but links I found was broken Cry | :((

Code Red

DirectShow with MFC

juryu29-Sep-03 7:09

juryu

29-Sep-03 7:09

Hi guys,

I am just starting to use DirectShow. I've managed to make it play a video in a CStatic in my dialog box. But now I want to draw something else there, like, put something on top of the video that is playing. I've tried using the device context from the CStatic but that doesn't seem to work - I guess I "gave" it to DirectShow and don't have control over it anymore. Another possibility would be to put another CStatic in front of the video playing, but that doesn't seem to work either, the video just plays over everything! Any suggestions?

Re: DirectShow with MFC

Ravi Bhavnani29-Sep-03 8:42

Ravi Bhavnani

29-Sep-03 8:42

See Stephane's articles Video overlay using Microsoft DirectShow[^] and Video overlay part II - An introduction to hypervideo[^].

/ravi

Let's put "civil" back in "civilization"
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ravib@ravib.com

JPEG2000

gicio29-Sep-03 7:00

gicio

29-Sep-03 7:00

am trying to load JPEG2000 (J2k) image and make use of the scalability features provided by J2k
by showing the image while loading. The tutorials clearly show that there are two possible “modes”:

- Progressive by resolution (You load the picture and it becomes sharper while loading, something
like interlaced GIF)

- Progressive by accuracy (ROI – region of interest)

I am interested in the first: “Progressive by resolution”. So I want to show the image while loading
for example if you download a 2 MB image through Modem connection.

I am looking for a exemplary implementation - does not matter in which language or platform it is running.

I would be grateful for any help.

Regards,

gicio

Internet Explorer Context Menu?

MKlucher29-Sep-03 6:27

MKlucher

29-Sep-03 6:27

There any good beginner tutorials on making a context menu plug-in for Internet Explorer. I have come across a few articles here but none of them have the source code or the point you to MSDN to read about it. Trying to find something thats easy to follow.

Thanks!

Re: Internet Explorer Context Menu?

Neville Franks29-Sep-03 11:00

Neville Franks

29-Sep-03 11:00

If you just want to add items to the IE context menu that is easy. I imagine there is a way to replace it, but don't know how. What are you trying to do?

Neville Franks, Author of ED for Windows. Free Trial at www.getsoft.com

Re: Internet Explorer Context Menu?

J. Dunlap29-Sep-03 11:49

J. Dunlap

29-Sep-03 11:49

If you are talking about for all pages, you can replace the IDocHostUIHandler[^] implementation.

If you're talking about replacing it for just one page, have a look at this article: Replacing the Internet Explorer context menu with a custom built context menu[^].

"Blessed are the peacemakers, for they shall be called sons of God." - Jesus

"You must be the change you wish to see in the world." - Mahatma Gandhi

Re: Internet Explorer Context Menu?

MKlucher29-Sep-03 19:49

MKlucher

29-Sep-03 19:49

Thanks for the relpys. I kinda know how do add an item to the context menu (This is done through the registery) but what I would like info on is creating the DLL to grab the text thats selected and all that good stuff. Just something to get me started would be great. As an example (Not exactly but close) is just have an extra selection come up when I have selected text that says like Search for on goole then have my DLL get the text and post to google or wherever.

Inheriting existing dialogs

PaulUK0129-Sep-03 6:22

PaulUK01

29-Sep-03 6:22

Hi. I have created a dialog called LOADS. This uses 8 radio buttons to allow the user to select the load (Hi / Low) on one of four instances of a wheelspeed transducer(WST). I therefore create an instance of LOADS in my main dialog:

LOADS WST

A second type of transducer is an Anti Skid Valve (ASV), but this has 6 instances of which I wish to set the load. The way I've implemented this is to have all six instances (12 radio buttons) on the LOADS dialog, and I pass a switch to DoModal() to tell it wether or not to disable the other two sets of radio buttons:

LOADS WST;
LOADS ASV;

if(WST.DoModal(1)!=IDOK)
return;

if(ASV.DoModal(0)!=IDOK)
return;

Then, in the LOADS functionality I can disable the unwanted radio buttons if the parameter to DoModal=1, and enable them if parameter =0;

Question: Instead of doing the above, how can I inherit a LOADS dialog so that I create a new dialog (eg LOADSASV) which I can then add the extra radio buttons to, thus replACING THE ABOVE CODE WITH:

LOADS WST;
LOADSASV ASV;

Can you help or point me to a suitable article? Thanks in advance.

Paul

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