March 22nd, 2002, 03:57 AM
Picture box control is hard work
I am using a picture box in my application to display a bitmap. However on a radio button it should clear the contents of the bitmap.
I have been trying for ages to find a way to clear the contents.
However im not getting anywhere.
My app is kinda like mouse spy so I copy the contents under the mouse to the box. So you should think there would be a command to clear the contents but I cant find any documentation for visual c++ on the stupid picture box control
March 22nd, 2002, 06:59 AM
you need to set the picture property of picture box to nothing.
in VB i use the following.try similar statement in VC as well.it should work.
Set Picture1.Picture = Nothing
March 22nd, 2002, 07:55 AM
Yeah VB makes super light work of this,
However can you think of the command I need to send to the control?
There must be something.
March 22nd, 2002, 03:27 PM
did you try "Picture1.Picture=null;" ? this would be the corresponding command to the vb one.
i donīt know that much about windows/c but in delphi i use:
you should be able to find the corresponding commands for c.
did this help?
March 22nd, 2002, 05:35 PM
Well you say set picture1 = null etc but in c its does not seem anywhere near as easy :-(
I have implemented a slight workaround which is to have 2 bitmaps one which never changes and one which shows the bitmap, I just toggle the visible state. Its not great but it works fine.
Unless someone actually has any C code to set the picturebox control back to nothing (ie show the button face colour again).
March 23rd, 2002, 05:24 AM
does my second suggestion not work? it should...
you destroy the old bitmap (free the memory) and just create a new one. let me try to translate the lines to c:
did this help? (maybe donīt destroy the picture but the bitmap inside... this got me stuck for some hrs too)
March 25th, 2002, 06:54 AM
The following will work for you.you just release the picture box after the use:
March 25th, 2002, 07:29 AM
this seems to be going on :-)
Im using straight C so I dont actually have a ref to the control I have to send it messages.
So im busy trying to find out what to send it to clear itself :=-)
March 25th, 2002, 05:54 PM
Are you using the Active-X CPictureBox control or just a plain old Bitmap?
March 26th, 2002, 03:23 AM
Just a plain old bitmap control in bog standard C.
I have to send messages to controls since I dont actually have a physicall reference to them.
March 26th, 2002, 08:05 PM
Have you tried sending a WM_HIDE message to the control?
March 27th, 2002, 03:12 AM
yeah but that completely hides the control which is no good :-)
There has to be a simple way to send a clear message to a control (picture control)