How to set which display window opns?

[Bill Kelley]

On dual display systems, what determines which display a window opens on?

That is, I want to use ATL 8.1 to open a window with Create(),
but it does not seem to have a argument to specify display?

How do you ask a window which display it is currently on?

[kbw]

Windows uses it's cascading rules to decide what's opened where if the default position is requested.

That aside, it tries to put it where requested.

[LB]

I think the second monitor is considered 'more' of the first monitor, so the coordinates carry over.

If you have two monitors side by side, each 10x10 pixels (for example):

.--------.  .--------.
|   A    |  |        |
|        |  |  B     |
'--------'  '--------'

Then it would be as if you had one 20x10 monitor. A might be at (5, 3), and B might be at (13, 6).

[webJose]

L B is correct. You can find the number of displays and their coordinates by calling EnumDisplayMonitors().

[Bill Kelley]

Thanks for all the answers! That's perfect. Even makes a lot of sense,
from good ol MS.

If I open a window B "owned" by Window A on screen 2, my assumption was that B would open near A, but it always opens on the same primary screen.

In Create() for the window, i passed in the value for default position, thinking near its owner would be the default.

Is there any way to ask Windows for a "safe" screen position near window A?

I know I can get A's position, but then I need to offset it a bit (cascade) and
then I need to make sure its all visible, not clipped off the bottom.

Is there a way I can just feed a position and say "make sure its visible", so I'm not reinventing the wheel there?