Get TrackBar Value in Form from a Thread - C / C++ / MFC Discussion Boards

Re: code to analyze bitmap then create predefined palette of colors in bitmap?

Richard Perrine24-Jan-09 5:14

Richard Perrine

24-Jan-09 5:14

Thank you, Stuart.

Re: code to analyze bitmap then create predefined palette of colors in bitmap?

Randor 24-Jan-09 6:59

Randor

24-Jan-09 6:59

Richard Perrine wrote:
can anyone help?

These are some excellent color quantization links that you may be interested in.

Floyd-Steinberg implemented in C[^]

Octree Color Quantization[^]

Best Wishes,
-David Delaune

explorer in Windows CE

Miss_F24-Jan-09 2:18

Miss_F

24-Jan-09 2:18

Hi,
I want to use an explorer in my program (it's a C++ program) which is under Windows CE platform. I want to know that is it applicable or not? If yes, does any body know how can I do it?
(If here is not a right forum, Sorry, I don't know under which topic I should write my question)
Thanks a lot
Sincerely Yours
Miss_F

Re: explorer in Windows CE

Stuart Dootson24-Jan-09 3:09

Stuart Dootson

24-Jan-09 3:09

Miss_F wrote:
an explorer

What do you mean by 'an explorer'? If you mean manipulating the filesystem/namespace using explorer interfaces like IFolderView[^], then I suspect you're out of luck. If you mean a treeview, then you should be OK[^].

Re: explorer in Windows CE

Miss_F24-Jan-09 3:15

Miss_F

24-Jan-09 3:15

I mean adding Internet browsing (using browser) functionality to my application.

Re: explorer in Windows CE

Stuart Dootson24-Jan-09 4:43

Stuart Dootson

24-Jan-09 4:43

Looks like you can[^]?

Re: explorer in Windows CE

Miss_F24-Jan-09 18:53

Miss_F

24-Jan-09 18:53

Thanks for your help

Get TrackBar Value in Form from a Thread

Member 391913824-Jan-09 1:16

Member 3919138

24-Jan-09 1:16

A trackBar->Value in a form has to be read out from a thread. I read so many articles, but still I got a problem.

I use a delegate which should return me the value of the trackBar position:
delegate int DelegateTrackBarCallBack(System::Object ^object);

I started the Thread by a ParametriziedThreadStart after a Button-Click

Thread^ oThread = gcnew Thread(gcnew ParameterizedThreadStart(&ProcessCANMessage::CAN_Thread::CANThread));

In CANThread I do

target_velocity=Get_TrackBar1_Value(object);

with

int ProcessCANMessage::CAN_Thread::Get_TrackBar1_Value(System::Object^ object)
{
   CAN_Anbindung::Form1^ form;
   form = (CAN_Anbindung::Form1^)object;
   int trackBar_Value;
   if (form->trackBar1->InvokeRequired==false)
   {
	   trackBar_Value=form->trackBar1->Value;
   }
   else
   {
	   CAN_Anbindung::Form1::DelegateTrackBarCallBack ^d = gcnew CAN_Anbindung::Form1::DelegateTrackBarCallBack(Get_TrackBar1_Value);
	   form->Invoke(d, gcnew array<system::object^>{form});
   }
   return (trackBar_Value);
}

During debugging the correct value is assigned to trackBar_Value. But when leaving Get_TrackBar1_Value trackBar_Value is set to "0".

Any ideas what to do?

Re: Get TrackBar Value in Form from a Thread

Stuart Dootson24-Jan-09 1:37

Stuart Dootson

24-Jan-09 1:37

Member 3919138 wrote:
Any ideas what to do?

Post to the C++/CLI[^] forum, as that's what you're using?

From what I can understand of your message, you're expecting trackBar_Value to keep its value in two different invocations of Get_TrackBar1_Value? Nope - local variables don't do that unless they're static. However - doesn't Invoke return the return value of the delegate? So you could do something like this?

trackBar_Value = form->Invoke(d, gcnew array<system::object^>{form});

You might need some casting to convert Invoke's return value from System::Object to int - wouldn't know - I've never really used .NET, never mind C++/CLI.

Re: Get TrackBar Value in Form from a Thread

Member 391913824-Jan-09 1:56

Member 3919138

24-Jan-09 1:56

I tried this befor
I got an error
1>.\ProcessCANMessage.cpp(74) : error C2440: '=': 'System::Object ^' kann nicht in 'int' konvertiert werden

Re: Get TrackBar Value in Form from a Thread

Stuart Dootson24-Jan-09 2:19

Stuart Dootson

24-Jan-09 2:19

Did you convert as shown in this article[^]?

int z = 44;
Object^ o = z; //implicit boxing
int y = *reinterpret_cast<int^>(o); //unboxing

Re: Get TrackBar Value in Form from a Thread

Chris.G.Weber24-Jan-09 6:40

Chris.G.Weber

24-Jan-09 6:40

I will try that. Thanks for your answers and help!

I used a code which shown in one of the articles from this forum which helps to control 4 Progressbars in a Form from 4 Threads.

See: http://www.codeproject.com/KB/mcpp/managedsafethreads.aspx[^]
It works fine, since the delegate function seems to be recalled until the InvokeRequired-property is false. in this case the progressbars can be controlled directly in the thread by "form->progressBar1->PerformStep();"
In my case I want to get the Value (Position) of the trackBar-component. So if the delegate function is called 2 times we have a recursive calling of the same function. I assumed that the return value is then overwritten by the previous call of my function "Get_TrackBar1_Value(object)".

I will let you know about the result.

Re: Get TrackBar Value in Form from a Thread

Member 391913824-Jan-09 8:12

Member 3919138

24-Jan-09 8:12

Everything is working fine...
Thanks again!

Help for Wizard look !

Le@rner24-Jan-09 0:50

Le@rner

24-Jan-09 0:50

Hi,

i m taking help from

http://www.codeproject.com/KB/dialog/wizard2000.aspx[^]

article its very gud article of wizard.

i m having 8 pages,there are no. of controls present.

if i run the application than its works fine but after some its look like hang or its not responding.

i m checking the memory usage from task manager than i have noticed that in thisapplication when i reached the last page of wizard the the memory of application constant.

but in my application after reached on last page,if i coninously click on back or next button than memory is still increase i think thats why it becomes not responding and looks like hang the applicaton.

please help me for this.

i m waiting for your reply.

thanks in advance.

To accomplish great things, we must not only act, but also dream;
not only plan, but also believe.

Re: Help for Wizard look !

Naveen24-Jan-09 1:04

Naveen

24-Jan-09 1:04

Seems you have the problem mentioned here[^]

nave

[OpenedFileFinder] [My Blog]

Re: Help for Wizard look !

Le@rner24-Jan-09 1:51

Le@rner

24-Jan-09 1:51

In this example property sheet not use to add property pages.

here the class is used for add pages is derived from CDialog base type class.

now what can i do.

please help me for this.

thanks in advance.

To accomplish great things, we must not only act, but also dream;
not only plan, but also believe.

[Message Deleted]

AnithaSubramani24-Jan-09 0:41

AnithaSubramani

24-Jan-09 0:41

[Message Deleted]

Re: Listener in MFC

Naveen24-Jan-09 1:01

Naveen

24-Jan-09 1:01

AnithaSubramani wrote:
Is it possible the listener for menu bar in MFC?

Listener??? What do you mean?

nave

[OpenedFileFinder] [My Blog]

Re: Listener in MFC

Rajesh R Subramanian25-Jan-09 4:47

Rajesh R Subramanian

25-Jan-09 4:47

Are you wantig to write a hook? That's the closest thing I can imagine... Confused | :confused:

It is a crappy thing, but it's life -^ Carlo Pallini

Re: Listener in MFC

Hans Dietrich25-Jan-09 9:04

Hans Dietrich

25-Jan-09 9:04

Do you mean you want to handle user clicks on menu entries?

Best wishes,
Hans

[CodeProject Forum Guidelines] [How To Ask A Question] [My Articles]

DebuggerEvents under C++ in Visual Studio [modified]

primexx23-Jan-09 22:31

primexx

23-Jan-09 22:31

Hello,

I'm writing an add-in in for Visual Studio in C++ and need to get access to the DebuggerEvents in Visual Studio. See here for a description: http://msdn.microsoft.com/de-de/libr...s_members.aspx . Especially I need to receive events from "OnEnterBreakMode". Unfortunately all these methods are marked as "internal use only". There is also no definition in the headers.
The interesting part is, that I can access and get notification from all these events within C# without any problem. (C# reference on DebuggerEvents: http://msdn.microsoft.com/de-de/libr...us,VS.71).aspx) So how can I manage to access the DebuggerEvents in C++?

thanks for your help in advance!
Peter

modified on Saturday, January 24, 2009 4:53 AM

SetLayeredWindowAttributes() - Undeclared identifier

ganesh.dp23-Jan-09 22:06

ganesh.dp

23-Jan-09 22:06

hi,
i am trying to transparent the dialog with color using this code. I included the windows.h and winuser.h
<pre>
SetLayeredWindowAttributes(GetSafeHwnd(),RGB(10,34,56),10,(LWA_COLORKEY|LWA_ALPHA));
</pre>

But it gives following error.

\\ITD254\VCC\Notes\NotesDlg.cpp(168) : error C2065: 'SetLayeredWindowAttributes' : undeclared identifier
\\ITD254\VCC\Notes\NotesDlg.cpp(168) : error C2065: 'LWA_COLORKEY' : undeclared identifier
\\ITD254\VCC\Notes\NotesDlg.cpp(168) : error C2065: 'LWA_ALPHA' : undeclared identifier

what i have to do

Ganesh

Re: SetLayeredWindowAttributes() - Undeclared identifier

Naveen23-Jan-09 22:39

Naveen

23-Jan-09 22:39

Which version of visual studio are you using? Have you set win version (_WIN32_WINNT ) to 0x0501 ?

nave

[OpenedFileFinder] [My Blog]

Re: SetLayeredWindowAttributes() - Undeclared identifier

ganesh.dp23-Jan-09 22:56

ganesh.dp

23-Jan-09 22:56

vc 6.0 and i tried #define WINVER 0x0500

Os- winxp

Re: SetLayeredWindowAttributes() - Undeclared identifier

ganesh.dp23-Jan-09 23:00

ganesh.dp

23-Jan-09 23:00

i opened the winuser.h and found that SetLayeredWindowAttributes() is not available.
for that i downloaded winuser.h, which has SetLayeredWindowAttributes() and replaced original but now compiler tells so many errors in winuser.h

any solution

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