C / C++ / MFC Discussion Boards

Ajay L D18-Jun-07 3:23

18-Jun-07 3:23

I was wondering if we could reset the semaphore count to 0 using any API. Is it possible? If yes, could anyone please tell me how?

Thank you,
AJ

Re: Reset the count of a Semaphore

Roger Stoltz18-Jun-07 3:52

Roger Stoltz

18-Jun-07 3:52

Ajay L D wrote:
I was wondering if we could reset the semaphore count to 0 using any API. Is it possible?

No.
You might want to read this article[^] on how to use semaphores and the difference between a mutex and a semaphore.

"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown

Re: Reset the count of a Semaphore

Arman S.18-Jun-07 4:11

Arman S.

18-Jun-07 4:11

As Roger stated, there is no way of doing that. The interesting point is that this even makes no sense (if we think a little bit deeper, of course). If it were possible, the whole schema of synchronization structure would worth nothing. Suppose, a thread holds a semaphore or a mutex by being sure that no other thread grabs it from itself... And what would happen if this were possible..?

--
=====
Arman

Re: Reset the count of a Semaphore

Joe Woodbury18-Jun-07 9:11

Joe Woodbury

18-Jun-07 9:11

while (WaitForSingleObject(handle, 0) == WAIT_OBJECT_0);

(Assuming handle is the semaphore handle)

Anyone who thinks he has a better idea of what's good for people than people do is a swine.
- P.J. O'Rourke

Audio Capture using DirectShow

Maynka18-Jun-07 3:07

Maynka

18-Jun-07 3:07

Hi all,
Please point me to any demo project which captures audio from any device e.g mike,etc and able to hear the captured audio using DiectShow.There are many examples but all are of video capture and display using DirectShow.

Thanks and Regards,
Mayank

Re: Audio Capture using DirectShow

Mark Salsbery18-Jun-07 5:29

Mark Salsbery

18-Jun-07 5:29

The same principles apply to audio.

The difference is in the filters used. For capturing the audio from a device you can use the
Audio Capture Filter. For rendering (playing) the audio you can use the Audio Renderer (WaveOut)
Filter.

The "AudioCap Sample" included with the SDK is a good place to start Smile | :)

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Help

suntromantralalalala18-Jun-07 2:17

suntromantralalalala

18-Jun-07 2:17

I have a program with threads and a class. In class i have a treeview , but i can't update it from thread.

<br />
foreach(DirectoryInfo d in dir.GetDirectories("*.*"))<br />
                {<br />
                    TreeNode new_node = new TreeNode(d.Name);<br />
                    nods.Nodes.Add(new_node);<br />
                 }<br />

Error:
Action being performed on this control is being called from the wrong thread. Marshal to the correct thread using Control.Invoke or Control.BeginInvoke to perform this action. at nods.Nodes.Add(new_node);

Help me!!!

Please excuse my english Smile | :)

Re: Help

James R. Twine18-Jun-07 2:26

James R. Twine

18-Jun-07 2:26

   Looks like you are getting bit by .NET's UI/Treading implementation/restrictions... Too bad this is not a .NET forum. :P

   (Tip: try the C# forum for C# issues...)

   Peace!

-=- James
Please rate this message - let me know if I helped or not!<HR>If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Avoid driving a vehicle taller than you and remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
See DeleteFXPFiles

Re: Help

Hamid_RT18-Jun-07 2:30

Hamid_RT

18-Jun-07 2:30

suntromantralalalala wrote:
foreach(DirectoryInfo d in dir.GetDirectories("*.*"))

Does your question about C++?

WhiteSky

Re: Help

Mark Salsbery18-Jun-07 5:33

Mark Salsbery

18-Jun-07 5:33

suntromantralalalala wrote:
foreach

foreach? What is this "foreach"? Poke tongue | ;-P

In C++ we use manly "for" loops Wink | ;)

(Just kidding C# people, geez!)

Try the C# board[^]

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Re: Help

Hamid_RT18-Jun-07 9:22

Hamid_RT

18-Jun-07 9:22

I think we need to foreach on the c++ I think its very powerful.

WhiteSky

How to embeded IE into a dialog ?

kcynic18-Jun-07 2:15

kcynic

18-Jun-07 2:15

I want to embed an IE window as a child window of my dilog,but when the user open a linker,the new page would not open in the real IE,but in my embeded child window.
Thanks

Re: How to embeded IE into a dialog ?

James R. Twine18-Jun-07 2:25

James R. Twine

18-Jun-07 2:25

You can capture link-based events (it may be as easy as handing the Navigate and similar events) to enforce their behavior. For example, you can cancel them, force them into a new window, or force them into a specific window. IIRC, there is a target parameter that specifies the intended target for the link.

Peace!

Re: How to embeded IE into a dialog ?

kcynic19-Jun-07 1:17

kcynic

19-Jun-07 1:17

Thanks

Re: How to embeded IE into a dialog ?

Mahesh Kulkarni18-Jun-07 3:13

Mahesh Kulkarni

18-Jun-07 3:13

Hi...
I think ur problem may solve by Using the IWebBrowser2 Interface.

The secret of life is not enjoyment
but education through experience.
- Swami Vivekananda.

Re: How to embeded IE into a dialog ?

kcynic19-Jun-07 1:18

kcynic

19-Jun-07 1:18

Thanks.I will try to learn such things

Tool tip on a button

_AnsHUMAN_ 18-Jun-07 1:43

_AnsHUMAN_

18-Jun-07 1:43

Hi All,
In my application I have a button with an Icon. I load the icon on the button using the LoadImage API and then SetIcon(). The button does not have it's owner draw property set to true, only it's Icon Property is set to true. When the user hovers the button with the mouse a tool tip is shown. The problem is that, the tooltip is only shown when the icon is shown in the disabled state. When the icon is in the enabled state the tooltip is seen only if the mouse is hovering on the corner of the button.
Can anyone help or provide some ideas on how to show the Tooptip when the user is hovering over the button with an icon?
PS: I am not allowed to subclass the button control Frown | :(

Atleast by adding a new class to the application's code base.

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

Re: Tool tip on a button

James R. Twine18-Jun-07 2:12

James R. Twine

18-Jun-07 2:12

   This does not sound like standard button behavior to me. I would be interested to know how the tooltips are implemented. Is the tooltip control having events passed to it, or is it hooking/subclassing the button control itself (TTF_SUBCLASS)?

   I have done icon buttons like this many times with tooltips and never had a problem like you are describing, other than when the button is disabled, the tooltip is not normally shown. So I think some special tooltip handling is being done which is broken.

   Peace!

Re: Tool tip on a button

_AnsHUMAN_ 18-Jun-07 3:10

_AnsHUMAN_

18-Jun-07 3:10

The tool tips are being implemented by passing the events.

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

Re: Tool tip on a button

Hamid_RT18-Jun-07 2:35

Hamid_RT

18-Jun-07 2:35

See this[^] thread does helpful?

WhiteSky

Graph Creation

Neo Andreson18-Jun-07 1:25

Neo Andreson

18-Jun-07 1:25

can anybody help to plot Graph on Notepad using VC++ 6.

There Is Nothing Right Or Wrong

Re: Graph Creation

_AnsHUMAN_ 18-Jun-07 1:34

_AnsHUMAN_

18-Jun-07 1:34

What do you exactly mean by saying that "plot a graph on notepad"? Can you provide some more details?

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

Re: Graph Creation

James R. Twine18-Jun-07 1:46

James R. Twine

18-Jun-07 1:46

If you mean something like drawing a graph using only ASCII characters, try looking Here[^].

Peace!

conersion into blob datatype

p_18-Jun-07 1:23

18-Jun-07 1:23

hi
can anybody tell me how to convert a cstring type into blob datatype of mysql

please .........
thanks Rose | [Rose]

Re: conersion into blob datatype

David Crow18-Jun-07 3:17

David Crow

18-Jun-07 3:17

Posting the same question with a different subject, within a few hours of the last time, is not going to get you help any faster. While your question is being digested by others (which might take 24 hours for everyone to see it), experiment more with your code.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

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