C / C++ / MFC Discussion Boards

Re: How can i detect the the Program Files Folder

Michael Dunn28-Aug-04 13:50

28-Aug-04 13:50

Absolutely not. Use the APIs for getting folder paths, they were written to insulate programs from changes in where the OS keeps folder paths (who knows where they're going to be held in Longhorn, for example...)

--Mike--
Personal stuff:: Ericahist | Homepage
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----
Pinky, are you pondering what I'm pondering?
I think so Brain, but if we shaved our heads, we'd look like weasels!

Parallell processes

delis28-Aug-04 0:56

delis

28-Aug-04 0:56

When I convert mp3 to ogg files on the command promt I use a pipe like this:
"lame --decode abc.mp3 - | oggenc -o abcogg -"
I can't use a regular ShellEx function to do this in a program of my own; because the pipe will be sent as an argument to lame. How do I do this. I've tried starting two processes and redirecting their output and input, but I can't make it work.

Re: Parallell processes

Joaquín M López Muñoz28-Aug-04 9:23

Joaquín M López Muñoz

28-Aug-04 9:23

Maybe the simplest way is to issue this command via the system function.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: Parallell processes

delis29-Aug-04 2:43

delis

29-Aug-04 2:43

What do you mean by the system function?

Re: Parallell processes

Joaquín M López Muñoz29-Aug-04 2:47

Joaquín M López Muñoz

29-Aug-04 2:47

A function called system which is available by including the <stdlib.h> header.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Smart Pointers ??

zahid_ash28-Aug-04 0:35

zahid_ash

28-Aug-04 0:35

HI,

Wt are smart pointers and y we use them ?

thanx

Regards.

Re: Smart Pointers ??

Lim Bio Liong28-Aug-04 7:22

Lim Bio Liong

28-Aug-04 7:22

Hello Zahid,

Smart Pointers are actually objects which wrap around actual memory pointers. These memory pointers usually point to objects which are reference counted.

Smart Pointers are usually bound to these object pointers on construction. During construction, a smart pointer would usually increment the reference count of the pointed-to object. For example

SmartPtr(Interface *& pInterface) :
m_pInterface(pInterface)
{
if (m_pInterface)
{
m_pInterface -> AddRef();
}
}

During destruction, the smart pointer will usually decrement the reference count of pointed-to object. For example :

~SmartPtr()
{
if (m_pInterface)
{
m_pInterface -> Release();
m_pInterface = 0;
}
}

Smart Pointers can also increase the ref count of their internal object pointers when they are assigned to another object. For example :

// Copies and AddRef()'s the interface.
//
SmartPtr& operator=(const SmartPtr& copypointer) throw()
{
if (operator!=(copypointer))
{
Interface* pOldInterface = m_pInterface;

m_pInterface = copypointer.m_pInterface;

if (m_pInterface)
{
m_pInterface -> AddRef();
}

if (pOldInterface)
{
pOldInterface -> Release();
pOldInterface = NULL;
}
}

return *this;
}

It is this automated reference increment and decrement feature of smart pointer objects that make them most useful for keeping the reference count of COM objects (through their interface pointers).

To properly keep track of COM objects (via their interface pointers), AddRef() and Release() calls must tally. Otherwise there will be reference undercount (leading to crashes) and reference overcount (leading to memory leaks). This is precisely what Smart Pointers are designed to overcome.

There are many more useful functionalities behind Smart Pointers. Lookup the definition of _com_ptr_t in MSDN.

Regards,
Bio.

How can I hide mouse pointer when it comes over my window

Atif Mushtaq28-Aug-04 0:09

Atif Mushtaq

28-Aug-04 0:09

as in the subject

Re: How can I hide mouse pointer when it comes over my window

Trollslayer28-Aug-04 2:19

Trollslayer

28-Aug-04 2:19

There are methods to change the pointer shape, why not just create a one pixel mouse pointer and use that ?

Elaine Rose | [Rose]

The tigress is here Big Grin | :-D

Re: How can I hide mouse pointer when it comes over my window

Graham Bradshaw28-Aug-04 2:23

Graham Bradshaw

28-Aug-04 2:23

Use the ShowCursor function. Despite its name, it can hide and show the cursor.

Re: How can I hide mouse pointer when it comes over my window

cmk28-Aug-04 11:12

cmk

28-Aug-04 11:12

Handle WM_SETCURSOR for the window and call SetCursor(NULL).

...cmk

Save the whales - collect the whole set

Re: How can I hide mouse pointer when it comes over my window

Mika Larramo2-Sep-04 13:04

Mika Larramo

2-Sep-04 13:04

You can use the ShowCursor Windows API function to show and hide the mouse pointer.

Tooltip for CListBox contents

Raghunandan S27-Aug-04 22:10

Raghunandan S

27-Aug-04 22:10

Hi All,
I wanted to know how to display the tooltips for the contents of the CListBox.
The length of the strings that are inserted into the CListBox is larger than the width of the CListBox.For such strings I want to display a tooltip text containing the full string when user places the cursor on them.Can someone tell me how to realize this.

I want to implement something like the tooltips displayed for CTreeView when the contents of the node does not fit the window.

Thanks in advance

Regards
Raghu

Re: Tooltip for CListBox contents

Ivan Cachicatari28-Aug-04 19:06

Ivan Cachicatari

28-Aug-04 19:06

Hi,

You can read this articles:

ListBox With ToolTip Support[^] And List Box with ToolTips[^]

Ivan Cachicatari
www.latindevelopers.com

Detecting HTTP errors with HttpOpenRequest/HttpSendRequest

Michael Dunn27-Aug-04 21:21

Michael Dunn

27-Aug-04 21:21

I'm new to using the WinInet APIs and I'm stuck on something. If I request a bogus URL with HttpOpenRequest() and HttpSendRequest(), some servers will return HTML in response to the 404 error (example). The trouble is that the above two APIs will succeed because data is returned. Calling HttpQueryInfo() with the HTTP_QUERY_STATUS_CODE returns a code of 0, not 404.

So, the question is how can I tell when an HTTP error actually happens?

--Mike--
Personal stuff:: Ericahist | Homepage
Shareware stuff:: 1ClickPicGrabber | RightClick-Encrypt
CP stuff:: CP SearchBar v2.0.2 | C++ Forum FAQ
----
Pinky, are you pondering what I'm pondering?
I think so Brain, but if we shaved our heads, we'd look like weasels!

Reading a bitmap to a 2D array

davidgin12327-Aug-04 20:59

davidgin123

27-Aug-04 20:59

Hi, I am doing image processing and need to manipulate the pixels of the bitmap. Thus, I need to read the pixel from the bitmap to a 2D array. Is there any way to do this? Or is there any library that do that for me?

Re: Reading a bitmap to a 2D array

Vaclav29-Aug-04 8:30

Vaclav

29-Aug-04 8:30

Check CxImage library. Procedure "Filter" and others reads bitmap.
Vaclav

Table selection

Member 52815527-Aug-04 20:39

Member 528155

27-Aug-04 20:39

Hi,
Iam using dhtml control in my application. Iam having a problem in table selection. For Example: if i put 2 * 3 table and try to select from 2row and 2 column in upwards direction it is selecting 1 row ,3 column also. And merge cells is not activating if the selection is not exact....
Kindly help...

I downloaded the dhtml edit from msdn..

Thanx.

Raj

ms flexgrid

Mike Danberg27-Aug-04 17:13

Mike Danberg

27-Aug-04 17:13

hi everyone,

I'm trying to use the activex control MS Flexgrid. However, if I try to add it to a dialog it tells me that it can't be instantiated because I don't have a run-time license. From what I was able to dig up searching the net about this problem was that I needed to manually give the control a license. This makes no sense to me as I don't understand why you'd need to do something like that if its already in visual c++. Now I don't know the first thing about ActiveX or COM so that might be why. Is there any way to use this control without knowing ActiveX? I just want to be able to have a nice database view such as in Access or if you chose a database view using the single doc architecture (i'm using dialog based). Right now I'm stuck using a listview which simply doesn't look as nice. I suppose I could try using a grid from one of the articles on this site, but it'd be easier to just use the ms flexgrid if possible.

Thanks,
Mike

ReadFile and reading a single line of text

Paolo Ponzano27-Aug-04 13:08

Paolo Ponzano

27-Aug-04 13:08

hello,
I'm porting some old code from C to Windows code, I'm in a little trouble, suppose I've got a text file, I need to copy single line of text into a listview,
before I did something like

<br />
FILE *fMMC=fopen(filename,"r");<br />
.<br />
.<br />
.<br />
while(!feof(fMMC))<br />
	{<br />
		while (fgets(buffer,BUFFER_SIZE,fMMC))<br />
		{ ....insert buffer into listview<br />
                }<br />
        }<br />
<br />
<br />

now porting to Windows code, I did someting as

 HANDLE fMMC=CreateFiles(..all_the_parameters)...<br />
<br />
while(true)<br />
{<br />
 DWORD br;<br />
   ReadFile(fMMC, buffer, 255, &BR, NULL))	 break;<br />
<br />
}<br />

my question is : in buffer, I can have multiple lines, since with fgets it takes a whole line and stop, with ReadFile I can have 2/3/4 lines depending of each lenght, how do I can retrieve from buffer only 1 line at time? is there a simple way? so that if buffer is composed of 3 lines, i get 3 item in listview

Thanks in advance
Paolo

p.s. if it's possible in some way to copy only a line as fgets does, it would be much more better, thanks again

Re: ReadFile and reading a single line of text

darkbyte27-Aug-04 13:53

darkbyte

27-Aug-04 13:53

You have to parse the text yourself.

If you feel the file will always be small, then i suggest you load it completely in 1 pass, then parse that memory chunk.

Otherwise, you need to parse a little differently and take care not only of \n but also of when you reached the end of the buffer and have to reload another segment.

Hope this gives you a hint.

Application event and messages "sniffer"

27-Aug-04 12:16

Hi,

is there a way to monitor events and messages sent from/to for a particular application? If so, how? Confused | :confused:

Thanks!

Re: Application event and messages "sniffer"

darkbyte27-Aug-04 13:48

darkbyte

27-Aug-04 13:48

i highly recommend (hope i'm not going to be bashed) that you look at http://www.sysinternals.com[^]

They have many usefull simple apps, and very often with source code.

P.S.: I am in no way affiliated to sysinternals, i just use their apps that i find very usefull.

Re: Application event and messages "sniffer"

Charlie Williams27-Aug-04 14:07

Charlie Williams

27-Aug-04 14:07

darkbyte wrote:
hope i'm not going to be bashed

I certainly hope you wouldn't get bashed for recommending an excellent resource such as sysinternals.

Charlie

if(!curlies){ return; }

Re: Application event and messages "sniffer"

LukeV27-Aug-04 18:28

LukeV

27-Aug-04 18:28

Thanks!

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