Utility method to set Window's location and size

WindowHelper.cs

using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;

public static class WindowHelper
{
    public static void SetWindowRect(Window window, int x, int y, int width, int height)
    {
        IntPtr windowHandle = new WindowInteropHelper(window).EnsureHandle();
        GetWindowPlacement(windowHandle, out WINDOWPLACEMENT windowPlacement);

        int left = x;
        int top = y;
        int right = x + width;
        int bottom = y + height;

        if (window.WindowStyle != WindowStyle.None)
        {
            IntPtr monitorHandle = MonitorFromPoint(new POINT(x, y), MONITOR_DEFAULTTO.MONITOR_DEFAULTTONULL);
            if (monitorHandle != IntPtr.Zero)
            {
                if (TryGetMonitorDpi(monitorHandle, out DpiScale dpi))
                {
                    const double DefaultExtendedFrameBoundsThickness = 7D;
                    int extendedFrameBoundsThickness = (int)(DefaultExtendedFrameBoundsThickness * dpi.PixelsPerDip);

                    left -= extendedFrameBoundsThickness;
                    right += extendedFrameBoundsThickness;
                    bottom += extendedFrameBoundsThickness;
                }
            }
        }

        windowPlacement.rcNormalPosition = new RECT(left, top, right, bottom);
        SetWindowPlacement(windowHandle, ref windowPlacement);
    }

    private static bool TryGetMonitorDpi(IntPtr monitorHandle, out DpiScale dpi)
    {
        const double DefaultPixelsPerInch = 96D;

        if (GetDpiForMonitor(monitorHandle, MONITOR_DPI_TYPE.MDT_Default, out uint dpiX, out uint dpiY) == S_OK)
        {
            dpi = new DpiScale(dpiX / DefaultPixelsPerInch, dpiY / DefaultPixelsPerInch);
            return true;
        }
        dpi = default;
        return false;
    }

    [DllImport("User32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool GetWindowPlacement(
        IntPtr hWnd,
        out WINDOWPLACEMENT lpwndpl);

    [DllImport("User32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool SetWindowPlacement(
        IntPtr hWnd,
        [In] ref WINDOWPLACEMENT lpwndpl);

    [StructLayout(LayoutKind.Sequential)]
    private struct WINDOWPLACEMENT
    {
        public uint length;
        public uint flags;
        public uint showCmd;
        public POINT ptMinPosition;
        public POINT ptMaxPosition;
        public RECT rcNormalPosition;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct POINT
    {
        public int x;
        public int y;

        public POINT(int x, int y)
        {
            this.x = x;
            this.y = y;
        }
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct RECT
    {
        public int left;
        public int top;
        public int right;
        public int bottom;

        public RECT(int left, int top, int right, int bottom)
        {
            this.left = left;
            this.top = top;
            this.right = right;
            this.bottom = bottom;
        }
    }

    [DllImport("User32.dll")]
    private static extern IntPtr MonitorFromPoint(
        POINT pt,
        MONITOR_DEFAULTTO dwFlags);

    private enum MONITOR_DEFAULTTO : uint
    {
        MONITOR_DEFAULTTONULL = 0x00000000,
        MONITOR_DEFAULTTOPRIMARY = 0x00000001,
        MONITOR_DEFAULTTONEAREST = 0x00000002,
    }

    [DllImport("Shcore.dll", SetLastError = true)]
    private static extern int GetDpiForMonitor(
        IntPtr hmonitor,
        MONITOR_DPI_TYPE dpiType,
        out uint dpiX,
        out uint dpiY);

    private enum MONITOR_DPI_TYPE
    {
        MDT_Effective_DPI = 0,
        MDT_Angular_DPI = 1,
        MDT_Raw_DPI = 2,
        MDT_Default = MDT_Effective_DPI
    }

    private const int S_OK = 0x0;
}