Re: Create Hidden window for drawing?
I have some fairly complex code that I'm not willing to post here.
But basically, you declare a memory DC.
CDC dcMem;
Then call dcMem.CreateCompatibleDC(). Note from the docs that if the
argument is NULL, a memory device context is created that is compatible with
the screen.
By default, a DC created this way has a 1x1 black and white bitmap. So you
need to declare a CBitmap and call CBitmap::CreateCompatibleBitmap() of the
size you need. Then, you must select the bitmap into dcMem.
At this point, you should be able to draw to the bitmap using dcMem just
like you would draw to a window.
--
Jonathan Wood
SoftCircuits Programming
http://www.softcircuits.com
"Sam_2" <Sam2@discussions.microsoft.com> wrote in message
news:96EFDFFC-F936-4C5A-B871-A7DBD43BA66C@microsoft.com...
Could you give me an example to create a Memory DC without using CWnd* nor
pDC* ? Thanks.
Sam_2
"Jonathan Wood" wrote:
Wrong. You can create a DC compatible with the screen. I see no reason
for a
separate window here. In fact, that's what seems to be working against
you.
--
Jonathan Wood
SoftCircuits Programming
http://www.softcircuits.com
"Sam_2" <Sam2@discussions.microsoft.com> wrote in message
news:4E308ADD-59F4-4DFD-B959-47121282F7FE@microsoft.com...
Thanks for your reply Jonathan.
The reason why I need a hidden window is because my component does not
have
a CClientDC and I could not use the main window's client DC. I will
have
to
use its own Client DC. I could create a memory DC if and only if I have
a
client DC right? Thanks.
Sam_2
"Jonathan Wood" wrote:
Can you explain why you want a hidden window?
Why not just create a memory DC and draw to that? The memory DC will
contain
whatever you draw on it for saving to a file as it will not be
overlapped
by
other windows. What is the purpose of the Window?
--
Jonathan Wood
SoftCircuits Programming
http://www.softcircuits.com
"Sam_2" <Sam2@discussions.microsoft.com> wrote in message
news:E60EF98B-8353-406A-B779-D304972193CD@microsoft.com...
Hi all,
I am writting a MFC component that will create a hidden window, load
a
bitmap into the hidden window and then save the hidden window to
bitmap
file.
However, after I loaded the bitmap into the hidden window and save
the
window
into bitmap file using function I found in codeguru
(http://www.codeguru.com/cpp/g-m/bitmap/capturing/article.php/c4919/).
The
bitmap file only contain the desktop window instead of the hidden
window.
Is it possble to create a hidden window for drawing? Is there any
other
way
I could create a hidden area for the program to draw on and save the
area
to
file?
I could not draw to the client DC directly as I do not want user to
see
the
image at all. All I want to do is create a off screen window area,
load
a
bitmap and save that window to a bitmap file.
Thanks.