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

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

Re: SetLayeredWindowAttributes() - Undeclared identifier

Naveen23-Jan-09 23:07

Naveen

23-Jan-09 23:07

ganesh.dp wrote:
i opened the winuser.h and found that SetLayeredWindowAttributes() is not available.

The SetLayeredWindowAttributes() will not be existing in the header files that comes with visual studio 6. So either you can download the platform SDK from here[^] and integrate it with VC6

or

Call the SetLayeredWindowAttributes() dynamically, using the LoadLibrary() and GetProcAddress() functions. The SetLayeredWindowAttributes exists in user32.dll dll and the value of LWA_COLORKEY and LWA_ALPHA are...

#define LWA_COLORKEY 0x00000001
#define LWA_ALPHA 0x00000002

nave

[OpenedFileFinder] [My Blog]

Re: SetLayeredWindowAttributes() - Undeclared identifier

ganesh.dp23-Jan-09 23:28

ganesh.dp

23-Jan-09 23:28

i got user32.dll

but i have some doubt.
1. can i load that dll from my project folder(because i download that from web, my don't doesn't)
2. if load that file in dynamic mode, but before that compiler gives error(for setlayeredwondowattributes()).

Frankly saying i'm new to VC so please guide me

Re: SetLayeredWindowAttributes() - Undeclared identifier

Naveen23-Jan-09 23:39

Naveen

23-Jan-09 23:39

ganesh.dp wrote:
1. can i load that dll from my project folder(because i download that from web, my don't doesn't)

No you dont have to download it from net. That dll comes with the installation of OS. it exists in the "c:\WINDOWS\system32\user32.dll"

ganesh.dp wrote:
2. if load that file in dynamic mode, but before that compiler gives error(for setlayeredwondowattributes()).

ok. This is how to call that function dynamically.

#define LWA_COLORKEY 0x00000001
#define LWA_ALPHA 0x00000002 
typedef BOOL (WINAPI *pSetLayeredWindowAttributes)( HWND hwnd, COLORREF crKey, BYTE bAlpha, DWORD dwFlags ); 


HMODULE hUser32 = LoadLibrary( _T("User32.dll"));
pSetLayeredWindowAttributes fnSetLayeredWindowAttributes = (pSetLayeredWindowAttributes)GetProcAddress( hUser32, "SetLayeredWindowAttributes");
if( 0 == fnSetLayeredWindowAttributes )
{
	AfxMessageBox( _T("Failed to load SetLayeredWindowAttributes function"));
}
else
{
	// Call the SetLayeredWindowAttributes function
	fnSetLayeredWindowAttributes( m_hWnd, 0, 100, LWA_ALPHA );
}
FreeLibrary( hUser32 );

nave

[OpenedFileFinder] [My Blog]

Re: SetLayeredWindowAttributes() - Undeclared identifier

ganesh.dp24-Jan-09 0:10

ganesh.dp

24-Jan-09 0:10

thanx...

bit more problem now, there is no compilation error but no transparent or color change is happened..

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