Win10 WPF窗口定位错误

Question

I've experienced a bug(?) in windows 10 with window positioning. I've reproduced this in WPF. Lets say I create a window like so:

var d = new Window();
d.Width = 100;
d.Height = 100;
d.Left = 1000;
d.Top = 100;
d.WindowStyle = WindowStyle.None; 
d.ResizeMode = ResizeMode.NoResize;
d.Show();

I am on resolution 1920x1080, so I'd expect the left of the window to be just right of center at 1000px (as it was in windows 8), however It's not. With testing (by both hovering the mouse, and grabbing mouse coordinates, and also by testing with PointToScreen) it shows that the X (Left) position of the window is actually at 1250 and the Y (Top) position is 125. So all of the coordinates are being adjusted by a factor of 25%. However, if you check the Window.Left property, it still says 1000 dispite the window actually being located at 1250.

I immediately went looking for display settings in windows and I found this:

So I figured that if this was the culprit it was just a matter of detecting this some how, except I found that even changing this to 100% instead of 125% actually makes no change and the bug is still the same.

So has anyone else ran into this bug and if it is a matter of a windows display setting, is there any way to detect it?

Answer 1

With help from Cyral in the comments of the question, Find the DPI as such:

var dpiX = (int)typeof(SystemParameters).GetProperty("DpiX", BindingFlags.NonPublic | BindingFlags.Static).GetValue(null, null);
var dpiY = (int)typeof(SystemParameters).GetProperty("Dpi", BindingFlags.NonPublic | BindingFlags.Static).GetValue(null, null);

And then make the correction of: [Desired Pixel Coordinate] * (96 / [dpi])

This is due to the fact that WPF uses DPI and virtual pixels for layout instead of physical pixels.