Managing DEVMODE and DEVNAMES Before/After PrintDlgEx

Question

Hello,
I have a COM application that is using the PrintDlgEx method to manage custom printing and a tool that lets users preview printed pages on a map.  Our app gets the DEVMODE and DEVNAMES structures from the default printer at initialization time. 
So, all our usage of PrintDlgEx starts with us having a DEVMODE/DEVNAMES structure already. 
I have several questions about managing the DEVMODE and DEVNAMES structures properly.  My problem is that I have been unable to find examples that show examples that start with these structures before calls to PrintDlg.
Assertion #1 - DEVMODE/DEVNAME structures should always be HGLOBALs when interacting with PrintDlg/PrintDlgEx methods per the documentation.
Question #1: Is it OK for me to cache that in my client as HGLOBAL?  Or should I copy to local memory after calls and then copy back to HGLOBAL before showing again? Seems if I global lock, then I could just hang onto the HGLOBAL and save me some
steps.
Assertion #2 - PrintDlg/PrintDlgEx (and associated structs) state that the memory for hDevMode/hDevNames are changed on input and output.  In my questions/code, we are always passing in a DEVMODE/DEVNAMEs structure.
Question #2 - So, does that mean that I should always assume that I am getting back a different HGLOBAL after the call?  Meaning I should lock/cache the copy that comes back and not assume it was the same HGLOBAL I passed in?  Or does it just mean
that the content of the memory I provided in may be different?
Question #3 - If the user cancels the operation, does that mean the PrintDlg/PrintDlgEx method has freed the memory I passed into the method?  That would mean to me that I need to keep a copy of the DEVMODE/DEVANME before passing it in, just for the
sole purpose of the user canceling.  My DEVMODE/DEVNAME might be custom in my app (landscape/portrait) at that point and I don't want to lose the user's customizations.
Overall Flow
Here is the overall flow that I am using and I am curious to know if the flow is correct
At start of my app, get the DEVMODE/DEVNAMES for the default printer using PrintDlg with flags PD_RETURNDEFAULT | PD_RETURNDC.  I call GlobalLock for both DEVMODE/DEVNAME into a class member HGLOBAL.  I do not free the memory at this point as
I want to cache the DEVMODE/DEVNAME associated with the printer DC.
If the user selects print, I call GlobalUnlock on my cached HGLOBALS and assign them to the PRINTDLGEX.hDevMode and hDevNames members.  Then I call PrintDlgEx.
Assuming the user presses the 'OK/Apply' button, I then lock the PRINTDLGEX.hDevMode and hDevNames parameters using GlobalLock
Assuming the user presses 'Cancel', I lock my previous member (Has PrintDlgEx released this memory?).
The code repeats this process over the lifetime of the application. 
I also pass these DEVMODE and DEVNAME structures to PageSetupDlg so that the user can customize the output.  I use the exact same process of unlock/lock before and after. 
I realize this is a lot of questions, but I can't seem to find an overall guide to managing DEVMODEs/DEVNAMEs in a situation like this where an app caches locally the changes the user makes in the printer setup and page setup.
I guess my most important question is what do PrintDlg/PrintDlgEx do to the DEVMODE/DEVNAME when the user presses cancel.  This looks like a change I may have to make in my application.
Thanks a ton!
Brian R
Brian R.

Answer 1

Hi Brian R,
>>My problem is that I have been unable to find examples that show examples that start with these structures before calls to PrintDlg.
Here are some PrintDlg sample for you reference:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms646829(v=vs.85).aspx
If the function returns TRUE, the function uses these members to return handles to 
DEVNAMES structures containing the user input and information about the printer. You can use this information to prepare the output to be sent to the selected printer.
http://msdn.microsoft.com/en-us/library/windows/desktop/ms646942(v=vs.85).aspx
http://msdn.microsoft.com/en-us/library/windows/desktop/ms646844(v=vs.85).aspx
>>Question #3
The user clicked the Cancel button. The information in the
PRINTDLGEX structure is unchanged.
Regards,