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From: k.sahici on 11 Jun 2010 16:46
I found a library on CodeProject, named CPictureEx, to be able to
load
jpeg images in an MFC application. I created a control of type
CStatic
and then converted to this type(CPictureEx) to be able to associate
this control to an image.
I'm using this library in a dialog based project. No SDI/MDI.
I have a user-defined message to update the region of this CPictureEx
variable. When the main dialog receives my user-defined message it
successfully updates the region and displays the jpeg file.
However, it fails when it comes to unloading the jpeg file. I
realized
that WM_PAINT message has to be generated explicitly to be able to
unload the image. Because when I minimized and then maximized this
window, this jpeg file diappeared as I expected it to be.
I have used various combinations of InvalidateRgn, UpdateWindow, etc.
The only one that worked was "AfxGetMainWnd()->Invalidate();". As you
might guess, this causes an annoying flickering.
I guess this is a simple problem but unfortunately I'm not
experienced
with MFC.
I'd be grateful if anyone could give me an idea to solve it.
From: ScottMcP [MVP] on 11 Jun 2010 17:26
On Jun 11, 4:46 pm, "k.sahici" <k.sah...(a)gmail.com> wrote:
> I found a library on CodeProject, named CPictureEx, to be able to
> load
> jpeg images in an MFC application. I created a control of type
> CStatic
> and then converted to this type(CPictureEx) to be able to associate
> this control to an image.
> I'm using this library in a dialog based project. No SDI/MDI.
> I have a user-defined message to update the region of this CPictureEx
> variable. When the main dialog receives my user-defined message it
> successfully updates the region and displays the jpeg file.
> However, it fails when it comes to unloading the jpeg file. I
> realized
> that WM_PAINT message has to be generated explicitly to be able to
> unload the image. Because when I minimized and then maximized this
> window, this jpeg file diappeared as I expected it to be.
> I have used various combinations of InvalidateRgn, UpdateWindow, etc.
> The only one that worked was "AfxGetMainWnd()->Invalidate();". As you
> might guess, this causes an annoying flickering.
> I guess this is a simple problem but unfortunately I'm not
> experienced
> with MFC.
> I'd be grateful if anyone could give me an idea to solve it.

The control (CPictureEx) variable should be invalidated.
m_cpex.Invalidate();
The will generate WM_PAINT to the control.
From: k.sahici on 12 Jun 2010 00:52
On Jun 12, 12:26 am, "ScottMcP [MVP]" <scott...(a)mvps.org> wrote:
> On Jun 11, 4:46 pm, "k.sahici" <k.sah...(a)gmail.com> wrote:
>
>
>
>
>
> > I found a library on CodeProject, named CPictureEx, to be able to
> > load
> > jpeg images in an MFC application. I created a control of type
> > CStatic
> > and then converted to this type(CPictureEx) to be able to associate
> > this control to an image.
> > I'm using this library in a dialog based project. No SDI/MDI.
> > I have a user-defined message to update the region of this CPictureEx
> > variable. When the main dialog receives my user-defined message it
> > successfully updates the region and displays the jpeg file.
> > However, it fails when it comes to unloading the jpeg file. I
> > realized
> > that WM_PAINT message has to be generated explicitly to be able to
> > unload the image. Because when I minimized and then maximized this
> > window, this jpeg file diappeared as I expected it to be.
> > I have used various combinations of InvalidateRgn, UpdateWindow, etc.
> > The only one that worked was "AfxGetMainWnd()->Invalidate();". As you
> > might guess, this causes an annoying flickering.
> > I guess this is a simple problem but unfortunately I'm not
> > experienced
> > with MFC.
> > I'd be grateful if anyone could give me an idea to solve it.
>
> The control (CPictureEx) variable should be invalidated.
> m_cpex.Invalidate();
> The will generate WM_PAINT to the control.

Thank you for your reply.
I tried it but it didn't work. I still have to do something else for
the control to be repainted, such as minimizing the dialog.
Do you have any other idea?
From: Alex Blekhman on 12 Jun 2010 03:22
On 12-Jun-10 14:52, k.sahici wrote:
>> The control (CPictureEx) variable should be invalidated.
>> m_cpex.Invalidate();
>> The will generate WM_PAINT to the control.
>
> I tried it but it didn't work. I still have to do something else for
> the control to be repainted, such as minimizing the dialog.
> Do you have any other idea?

Scott is right. If his code doesn't work for you, then you do something
wrong. When you minimize the dialog, then WM_PAINT is generated for the
window once it pops up. So, it seems that your call to
CPictureEx::Invalidate doesn't invalidate the control.

Alex
From: ScottMcP [MVP] on 12 Jun 2010 08:36
> On 12-Jun-10 14:52, k.sahici wrote:
> > I tried it but it didn't work. I still have to do something else for
> > the control to be repainted, such as minimizing the dialog.
> > Do you have any other idea?

Are you testing with a debug build? That checks a lot of things for
you. Did you change the ID of the control? (IDC_STATIC won't work.)
Does the control have a DDX_Control call? Can't guess very well if
you don't show the code details.
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