How to get Windows Display settings?

Question

There is setting for Display in Windows 7 (Control Panel -> Display). It allows to change the size of the text and other items on the screen. I need to get this setting to be able to switch on/switch off some functionality in my C# application based on the setting value. Is that possible?

Answer 1

Both graphics.DpiX and DeviceCap.LOGPIXELSX return 96 on Surface Pro in all scaling levels.

Instead, I managed to calculate the scaling factor this way:

[DllImport("gdi32.dll")] static extern int GetDeviceCaps(IntPtr hdc, int nIndex); public enum DeviceCap {     VERTRES = 10,     DESKTOPVERTRES = 117,      // http://pinvoke.net/default.aspx/gdi32/GetDeviceCaps.html }     private float getScalingFactor() {     Graphics g = Graphics.FromHwnd(IntPtr.Zero);     IntPtr desktop = g.GetHdc();     int LogicalScreenHeight = GetDeviceCaps(desktop, (int)DeviceCap.VERTRES);     int PhysicalScreenHeight = GetDeviceCaps(desktop, (int)DeviceCap.DESKTOPVERTRES);       float ScreenScalingFactor = (float)PhysicalScreenHeight / (float)LogicalScreenHeight;      return ScreenScalingFactor; // 1.25 = 125% }