Screens.AllScreens[] is a WinForms method, if I'm not mistaken, but yes this supports all of your cases (as far as I know). If I remember correctly, that WinForms method initialized the static property on application startup and it wouldn't update if the screens were changed during runtime.
As you are dealing with WPF, I would avoid WinForms alltogether. Instead write your own Screens wrapper that p/invokes the Win32 API. Also, hook up an event handler to notify you when display settings change, for example:
Microsoft.Win32.SystemEvents.DisplaySettingsChanged += new EventHandler(this.SystemEvents_DisplaySettingsChanged);
This is the wrapper I use:
/// <summary>
/// This class deals with monitors.
/// </summary>
internal static class Monitors
{
private static List<Monitors.Screen> Screens = null;
internal static List<Monitors.Screen> GetScreens()
{
Monitors.Screens = new List<Monitors.Screen>();
var handler = new NativeMethods.DisplayDevicesMethods.EnumMonitorsDelegate(Monitors.MonitorEnumProc);
NativeMethods.DisplayDevicesMethods.EnumDisplayMonitors(IntPtr.Zero, IntPtr.Zero, handler, IntPtr.Zero); // should be sequential
return Monitors.Screens;
}
private static bool MonitorEnumProc(IntPtr hMonitor, IntPtr hdcMonitor, NativeMethods.DisplayDevicesMethods.RECT rect, IntPtr dwData)
{
NativeMethods.DisplayDevicesMethods.MONITORINFO mi = new NativeMethods.DisplayDevicesMethods.MONITORINFO();
if (NativeMethods.DisplayDevicesMethods.GetMonitorInfo(hMonitor, mi))
{
Monitors.Screens.Add(new Monitors.Screen(
(mi.dwFlags & 1) == 1, // 1 = primary monitor
mi.rcMonitor.Left,
mi.rcMonitor.Top,
Math.Abs(mi.rcMonitor.Right - mi.rcMonitor.Left),
Math.Abs(mi.rcMonitor.Bottom - mi.rcMonitor.Top)));
}
return true;
}
/// <summary>
/// Represents a display device on a single system.
/// </summary>
internal sealed class Screen
{
/// <summary>
/// Initializes a new instance of the Screen class.
/// </summary>
/// <param name="primary">A value indicating whether the display is the primary screen.</param>
/// <param name="x">The display's top corner X value.</param>
/// <param name="y">The display's top corner Y value.</param>
/// <param name="w">The width of the display.</param>
/// <param name="h">The height of the display.</param>
internal Screen(bool primary, int x, int y, int w, int h)
{
this.IsPrimary = primary;
this.TopX = x;
this.TopY = y;
this.Width = w;
this.Height = h;
}
/// <summary>
/// Gets a value indicating whether the display device is the primary monitor.
/// </summary>
internal bool IsPrimary { get; private set; }
/// <summary>
/// Gets the display's top corner X value.
/// </summary>
internal int TopX { get; private set; }
/// <summary>
/// Gets the display's top corner Y value.
/// </summary>
internal int TopY { get; private set; }
/// <summary>
/// Gets the width of the display.
/// </summary>
internal int Width { get; private set; }
/// <summary>
/// Gets the height of the display.
/// </summary>
internal int Height { get; private set; }
}
}
internal static class NativeMethods
{
/// <summary>
/// Methods for retrieving display devices.
/// </summary>
internal static class DisplayDevicesMethods
{
internal delegate bool EnumMonitorsDelegate(IntPtr hMonitor, IntPtr hdcMonitor, NativeMethods.DisplayDevicesMethods.RECT rect, IntPtr dwData);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool EnumDisplayMonitors(IntPtr hdc, IntPtr lprcClip, EnumMonitorsDelegate lpfnEnum, IntPtr dwData);
/// <summary>
/// Retrieves information about a display monitor.
/// </summary>
/// <param name="hmonitor">A handle to the display monitor of interest.</param>
/// <param name="info">A pointer to a MONITORINFO or MONITORINFOEX structure that receives information about the specified display monitor.</param>
/// <returns>If the function succeeds, the return value is nonzero.</returns>
[DllImport("user32.dll", CharSet = CharSet.Auto)]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool GetMonitorInfo(IntPtr hmonitor, [In, Out] NativeMethods.DisplayDevicesMethods.MONITORINFO info);
/// <summary>
/// The RECT structure defines the coordinates of the upper-left and lower-right corners of a rectangle.
/// </summary>
[StructLayout(LayoutKind.Sequential)]
internal struct RECT
{
public int Left;
public int Top;
public int Right;
public int Bottom;
}
/// <summary>
/// The MONITORINFO structure contains information about a display monitor.
/// </summary>
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto, Pack = 4)]
internal class MONITORINFO
{
internal int cbSize = Marshal.SizeOf(typeof(NativeMethods.DisplayDevicesMethods.MONITORINFO));
internal NativeMethods.DisplayDevicesMethods.RECT rcMonitor = new NativeMethods.DisplayDevicesMethods.RECT();
internal NativeMethods.DisplayDevicesMethods.RECT rcWork = new NativeMethods.DisplayDevicesMethods.RECT();
internal int dwFlags;
}
}
}
Screen.AllScreensin this answer - it may not report the correct screens if the screens change while your program is running, and after you've called it for the first time. – Fateful