Determine the size & position of an external program window

[HaLo2FrEeEk]

I'm updating a program that I wrote a few months back and I need to be able to determine the size and position of other program windows. I'm sure this is possible, but I just can't figure out how. I've tried Google and all of the results that I came up with were dead ends.

Basically I just need to see the location in screen coordinates and the size of the external window. How might I accomplish this?

[GaryTexmo]

I'm wondering if the GetWindowRect function in User32.DLL can help you.

http://msdn.microsoft.com/en-us/library/ms633519%28VS.85%29.aspx

The only thing I'm unsure about here is how to get the hWnd of the other windows. I've been looking around but if I put you on the same track as I am, I'm sure you'll find it sooner :)

Here's the thread I found that got me thinking this is how you might do it.

http://stackoverflow.com/questions/3849025/how-to-get-the-name-of-an-external-window-in-c-application

I took a quick glance through what's available in User32.DLL but didn't see anything outright, which doesn't mean it isn't there. I'll see if I can come back to this... but hopefully I've given you something to look into.

[GaryTexmo]

Ooooh!

http://www.daniweb.com/forums/thread185513.html

http://msdn.microsoft.com/en-us/library/system.diagnostics.process.aspx

The Process class has a Handle property, so you might be able to get it from there. If you get a chance to try this before I do, let me know how it works! :)

[HaLo2FrEeEk]

My apologies for taking so long to reply. I have managed to whip up some code that gathers a list of all running processes and allows me to get rectangle data for the active window. There are a few issues, for example the X and Y loations are correct, but since I have multiple monitors, for some reason my width and height are being displayed wrong. Each monitor is 1920x1200. I've got a window open that is 1696x1056, located at 2032x94, so my rectangle should be:

{X=2032, Y=94, Width=1696, Height=1056}

Intead it s returned as:

{X=2032, Y=94, Width=3728, Height=1150}

However, it seems to be as simple as subtracting the X from the Width and the Y from the Height to get the actual size of the window, so all I'd have to do is:

Rectangle rect = new Rectangle();
GetWindowRect(hWnd, ref rect);
rect.Width -= rect.X;
rect.Height -= rect.Y;

And I'll have the correct coordinates and size of an external window.

Now I just have to figure out how to detect when I put MY program window over the external one. Hmmm...

I'm finishing up a screenshot program that I wrote that allows the user to position a rectangle anywhere on the screen, size it however they want, then push a button to take a screenshot of that portion of the screen. It started off as a test of my abilities, but it's grown up quite a bit. What I want to do with what I just learned is allow the user to drag the screenshot rectangle over an external window and allow them to lock the rectangle to that window. Armed with this new knowledge, I think I can do it.