Thread: Using HDC to initialize data structure

Hello,
I need to create a compatible DC and compute a font height. Both of these initialization steps require a handle to the device context called HDC.

HDC hdc = GetDC(NULL);
dcImage = CreateCompatibleDC(hdc);
lfHeight = -MulDiv(12, GetDeviceCaps(hdc, LOGPIXELSY), 72);
ReleaseDC(NULL, hdc);

Should I create them in InitInstance or WM_CREATE? In my case I create the dcImage and lfHeight in the InitInstance routine.
On the WM_CREATE I finish the initialization procedure by using the SelectObject to finish the initilizaition of the device context called dcImage. It seems a bit artbitary because I could it either way.

Originally Posted by novacain

InitInstance is MFC and runs at the application level, not the window level.

I don't know what this means. I used Visual C++ 2011 expression to create a new C++ project.

You can always consult the people who made the thing: InitInstance Member Function

Quoting linked page:

Originally Posted by MSDN

WinMain calls InitInstance every time a new instance of the application starts.

So InitInstance runs once per application, not once per window.