Why does Window geometry change when migrating from VS2010 to VS2017? - c++

Question

I have a large Win API C++ Application that i recently moved from Visual Studio 2010 to 2017. Application compiles, links and runs now, but i find that the window borders are about 2 pixels larger than before.
This is a problem as we implemented docking windows long time ago with 100% own code. Although all sizes are retrieved from the OS using GetSystemMetrics etc. this turned out to need some more specific alignment. It took a lot of development time when developing (for Windows 2000) and retargeting later for Windows 7. Furthermore we have some small windows and the thicker frames just waste space.
So i installed the Windows SDK 7.1 and was able after some tweaks to install that. But i am not able to choose 7.1 in the project settings. Typing in that in the project settings results in
error MSB8036: The Windows SDK version 7.1 was not found.
Although I find a directory named:
C:\Program Files\Microsoft SDKs\Windows\v7.1
Also when trying to re-target the Project, the SDK 7.1 is not listed.
I did a lot of googling and found this and that but no substantial answer. msdn is horrible.
Questions (obsolet, see below):
Is it possible to use VC 2017 with Windows 7 SDK? How?
Is there possibly a different way to keep the geometry used with VC2010?
EDIT:
I don't think that this is a duplicate of Dialog border different after porting code from Visual Studio 6 to Visual Studio 2013 although the link is quite helpful. It turned out, that different values are returned for GetSystemMetrics(SM_CYFRAME). So far I do not see a substantial explanation for that. Please see my own answer and comments.
So let me update the question:
Why does the value returned from GetSystemMetrics(SM_CYFRAME) change when upgrading from VC2010 to VC2017?
What is the root cause?

Answer 1

Is it possible to use VC 2017 with Windows 7 SDK? How?
Yes, but I doubt this is the solution to your main problem.
Is there possibly a different way to keep the geometry used with VC2010?
Yes, just change the minimum subsystem version to pre-Vista value, like 5.01 (for Windows XP 32-bit). For some reason, 5.1 will yield the same result too; the resulting EXE would be the same.
When Win32 Subsystem Version is 6.0 or above, there is a behavior change regarding the window border size. Though I am not aware of where Microsoft has documented about this.
If you still have Windows 7, the difference is also obvious when you are using Windows Basic theme, as shown in this screenshot:
Screenshot added by RED SOFT ADAIR:

Answer 2

It turned out that the problem was as described here:
https://social.msdn.microsoft.com/Forums/windowsdesktop/en-US/eaae1445-264d-487f-aba1-52dfc8abdfe4/getsystemmetrics-difference-in-return-value-for-the-same-input?forum=windowssdk
The value returned for GetSystemMetrics(SM_CXFRAME) changed with VS 2013.
In VS2010 (Window 8.1)
GetSystemMetrics(SM_CXFRAME); // 8 pixels
In VS2013 (Window 8.1, same PC)
GetSystemMetrics(SM_CYFRAME); // 4 pixels
In VC2013 and later the same result will be returned using
GetSystemMetrics(SM_CXFRAME) + GetSystemMetrics(SM_CXPADDEDBORDER);
My windows still had the same frame size. I miss interpreted the root cause.
Still i do not understand how this can happen. By my understanding GetSystemMetrics is a function of the Windows OS. How can this function behave different when changing the compiler? I guess this IS part of the Windows SDK?
By the way, i found, that i can select "Windows 7.1" as the Platform Toolset, but not for the SDK (as i was thinking).
All this is confusing. Can anybody point out the differences and the junctions between SDK and Toolset?
EDIT:
I made a little sample program to prove this:
#include <windows.h>
#include <stdio.h>
int main(int argc, char *argv)
{
printf("GetSystemMetrics(SM_CXFRAME) returns: %d\n", GetSystemMetrics(SM_CXFRAME));
return 0;
}
Compiling with VC2010 results in "8".
Compiling with VC2017 results in "4".
Even if i choose "dont upgrade" for the SDK when migrating to VC2017.
If you dont believe it - try yourself.
If you have any more insights to that - you're welcome. I give you a 500 points bounty!