Re: LoadImage failure? - C / C++ / MFC Discussion Boards

Re: LoadImage failure?

Llasus17-Oct-07 21:32

Llasus

17-Oct-07 21:32

The code is actually too large to paste in here. I can only paste the function which displays has the LoadImage part.

	<br />
void CDlg::DisplayImage()<br />
{<br />
        //then use LoadImage and attach it to a BITMAP handle<br />
	gOtherClass.gDisplayPanelHandle = (HBITMAP)::LoadImage<br />
	( <br />
		0, <br />
		gMapPath, <br />
		IMAGE_BITMAP, <br />
		gSourceSize.cx,<br />
		gSourceSize.cy,<br />
		LR_DEFAULTCOLOR | LR_LOADFROMFILE <br />
	);<br />
<br />
	//check if GlobalMap.bmp was loaded<br />
	if(gOtherClass.gDisplayPanelHandle == NULL)<br />
	{<br />
		AfxMessageBox("Error!\nUnable to load Map File");<br />
		return;<br />
	}<br />
<br />
	//Attach the bitmap handle to the CDC for display<br />
	gCDC.SelectObject(gOtherClass.gDisplayPanelHandle);<br />
<br />
	//reverse image and stretch it to display correctly<br />
	gCDC.StretchBlt<br />
	(<br />
		0, <br />
		0,<br />
		gSourceSize.cx,<br />
		gSourceSize.cy,<br />
		&gCDC,<br />
		0, <br />
		gSourceSize.cy - 1,	//added - 1 to display image properly<br />
		gSourceSize.cx,<br />
		-gSourceSize.cy,<br />
		SRCCOPY<br />
	);<br />
        Invalidate(FALSE);<br />
}<br />

Re: LoadImage failure?

Hamid_RT17-Oct-07 21:57

Hamid_RT

17-Oct-07 21:57

What is gOtherClass.gDisplayPanelHandle?

Re: LoadImage failure?

Llasus17-Oct-07 22:21

Llasus

17-Oct-07 22:21

its a class which contains all the shared variables between other characters. I have noticed also that after around 100 times of loading a bitmap, the application's performance is starting to decline.

Re: LoadImage failure?

Naveen17-Oct-07 22:58

Naveen

17-Oct-07 22:58

Llasus wrote:
gOtherClass.gDisplayPanelHandle

Do you destroy the handle after every display?

nave

[OpenedFileFinder]

Re: LoadImage failure?

Llasus18-Oct-07 3:10

Llasus

18-Oct-07 3:10

yes. I made sure that it destroys the object before loading the next image.

Re: LoadImage failure?

jhwurmbach17-Oct-07 23:42

jhwurmbach

17-Oct-07 23:42

When calling SelectObject, you need to store the Pointer to the old GdiObject you get from the call and re-SelectObject it after finishing work.

You are producing a so called GDI-Resource-Leak. In the ProcessExplorer, you cann swith on display of used GDI-Objects.

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Re: LoadImage failure?

Llasus18-Oct-07 3:17

Llasus

18-Oct-07 3:17

Thank you for the help. I will try this tomorrow. I have not encountered this GDI-Resource-Leak though. Sorry but could you please explain further what you mean by re-SelectObject after finishing the work and why I need it? Usually when loading the next image I just use the DeleteObject() to somehow release the object for next use.

Re: LoadImage failure?

jhwurmbach18-Oct-07 3:24

jhwurmbach

18-Oct-07 3:24

Llasus wrote:
could you please explain further what you mean by re-SelectObject after finishing the work and why I need it?

What I mean is this:

<small>CBitmap m_bmpSnapshot = ...</small>
CBitmap* pOldBmp = dcSnapshot.SelectObject(&m_bmpSnapshot);
dcSnapshot.BitBlt(0, 0, width, height, &dc, 0, 0, SRCCOPY);
dcSnapshot.SelectObject(pOldBmp);

Let's think the unthinkable, let's do the undoable, let's prepare to grapple with the ineffable itself, and see if we may not eff it after all.
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Re: LoadImage failure?

Llasus18-Oct-07 4:01

Llasus

18-Oct-07 4:01

I see. thank you very much for the help! I will try to test this tomorrow. Again, thank you very much for the time and help!

Re: LoadImage failure?

Llasus18-Oct-07 15:53

Llasus

18-Oct-07 15:53

It worked! Thank you so much for your help. I was never aware of the possibility that GDI may leak if you don't save and re-select the pointer that SelectObject returned. I did past applications though without doing that. Though not as much on loading in images like this one. Again, thank you to all that helped specially jhwurmbach. Smile | :)

Japanese email attachments

monsieur_jj17-Oct-07 19:54

monsieur_jj

17-Oct-07 19:54

Hi all,

Is there a way to get the codepage of a japanese attachment with a japanese filename? What property can I use to get this?

Thanks,
Jj

Minidumps

Programm3r17-Oct-07 19:31

Programm3r

17-Oct-07 19:31

Hi all,

I know how to create minidumps in VC++, but I tried doing the same thing using C++ Builder Professional with no luck. Message I receive is that no debug binaries were loaded. So does anybody know or have done it before in Borland?

Many Thanks
Regards,

The only programmers that are better that C programmers are those who code in 1's and 0's Green Alien | [Alien]

Programm3r
My Blog: ^_^

Assertion failed

mosali satish17-Oct-07 19:29

mosali satish

17-Oct-07 19:29

hi
i have developed a GUI in which i have used static LED which is provided by Digistatic .h.i have added a combo box to it , created a member for it and executed the application.when iam closing the application assertion failed message is being displayed. this message is being display only when i try to create an object of the class to which the control belongs to ( for ex CComboBox m_cmbBaudrate).when i create a member as (string m_cmbBaudrate ) it is not giving any message.
so please can anyone help me to sort out this issue.

sathish

Re: Assertion failed

Hamid_RT17-Oct-07 19:57

Hamid_RT

17-Oct-07 19:57

Did you use of breakpoints and debugger for see error?

Re: Assertion failed

Nelek17-Oct-07 21:04

Nelek

17-Oct-07 21:04

Most probably will be a failure with your destructor. The controls need a handler to the parent window. and when you close, and the destructor o the window try to call the destructor of the control. The control has no owner and he asserts.

Is the same as if u want to load some strings in the CComboBox inside the constructor of the dialog, you will have the same assertion. You have to load the datas in OnInitDialog or OnInitialUpdate, insteads of in the constructor.

With the CString you dont have any problem because they are not having such issues.

Take a look where you use the CComboBox and try debugging step by step to find out the secuence o opening/ closing a dialog. I did that using all the messages in relation with creating/destroying a Dialog and just putting an AfxMessageBox with the name of the message calling it and some text inside

Greetings.

--------
M.D.V.

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?

Help me to understand what I'm saying, and I'll explain it better to you

Wink | ;)

Re: Assertion failed

David Crow18-Oct-07 2:48

David Crow

18-Oct-07 2:48

mosali satish wrote:
i have developed a GUI in which i have used static LED which is provided by Digistatic .h.

I did this once here.

mosali satish wrote:
when iam closing the application assertion failed message...

What line of what file is asserting?

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

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ScrollBar Limitations

paresh_joe17-Oct-07 19:24

paresh_joe

17-Oct-07 19:24

Hi all,

right now i am working on a project in which i am using inhouse list component which is using MFC Scrollbar . problem is that when that List is filled with around 40000 records and when i am moving Tracker of and reach to the position "32768" (tracker value) it is getting reset to first position.

this is happening beacuse the in the core file "wincore.cpp" (which is actually handling this event) getting parameter wParam (which is UINT ptr) and from this parameter it is actually retrieving Tracker value. wParam can contain max 2147483648 value.

when tracker reaches to 32768th row its holding 2147483653 , which is beyond range of integer.

Now can anyone tell me whats the solution if i have more than more than 32767 records in a single page , or is there any option in ScrollBar that can handle this situation ?

Thank You ,
Perry

Re: ScrollBar Limitations

Roger Broomfield17-Oct-07 20:16

Roger Broomfield

17-Oct-07 20:16

Extract from http://msdn2.microsoft.com/en-us/library/z91cdf5a(VS.80).aspx[^]

The MFC Windows message handlers that indicate scroll bar position, CWnd::OnHScroll and CWnd::OnVScroll, provide only 16 bits of position data. GetScrollInfo and SetScrollInfo provide 32 bits of scroll bar position data. Thus, an application can call GetScrollInfo while processing either CWnd::OnHScroll or CWnd::OnVScroll to obtain 32-bit scroll bar position data.

Re: ScrollBar Limitations

paresh_joe17-Oct-07 20:34

paresh_joe

17-Oct-07 20:34

Thank you Roger ..

Hope this will work ... Smile | :)

Singleton class

Vinod CS17-Oct-07 18:44

Vinod CS

17-Oct-07 18:44

Hi,
In some of the singleton classes, I have seen that
People are keeping the destructor of singleton class in 'Public' Section of class.
Is it right to allow some one from outside to delete the singleton Object.

Thanks in advance,

Vinod.C.S

Re: Singleton class

ThatsAlok17-Oct-07 19:35

ThatsAlok

17-Oct-07 19:35

Vinod CS wrote:
Is it right to allow some one from outside to delete the singleton Object.

how could you delete the object of Singleton class from outside, when it is not exposed to you. whole singleton concept is depend on static data!, fronm which you manage the lifetime of singleton class!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
Never mind - my own stupidity is the source of every "problem" - Mixture

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
Support CRY- Child Relief and You

Re: Singleton class

Vinod CS17-Oct-07 20:08

Vinod CS

17-Oct-07 20:08

I was taking abt implementing singleton clas in Threadsafe way using 'new':
mySingletonClass* mySingletonClass::GetInstance
{
if( 0 == m_pmySingletonObject )
{
m_pmySingletonObject = new mySingletonClass;
}
return pmySingletonObject;
}

Thnaks in advance,

Vinod.C.S

Re: Singleton class

ThatsAlok17-Oct-07 20:53

ThatsAlok

17-Oct-07 20:53

Vinod CS wrote:
Threadsafe

then you might have to use syncronization object!

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
Support CRY- Child Relief and You

Re: Singleton class

Cedric Moonen17-Oct-07 20:10

Cedric Moonen

17-Oct-07 20:10

By providing a public Destroy function that will delete the instance pointer. This way, you enforce a correct usage of the class.

As the pointer is deleted from within a member function, the destructor can be made private.

Cédric Moonen
Software developer

Charting control [v1.2]

Re: Singleton class

ThatsAlok17-Oct-07 20:54

ThatsAlok

17-Oct-07 20:54

Cedric Moonen wrote:
As the pointer is deleted from within a member function, the destructor can be made private.

Hi Cedric,
I doesn't understand what you want to say.. is there is any short coming in my comment!

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
Support CRY- Child Relief and You

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