Обрабатывать mouseMove для формы, даже если курсор находится над контроллом

using System.Collections.Generic;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
 
namespace WindowsFormsApplication1
{
    public struct POINT
    {
        public int X;
        public int Y;
    }
 
    public partial class Form1 : Form
    {
        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool GetCursorPos(out POINT lpPoint);
 
        public IEnumerable<Control> AllControls(Control control)
        {
            foreach (Control _contrl in control.Controls)
            {
                yield return _contrl;
                if (_contrl.Controls.Count > 0)
                    foreach (Control childControl in AllControls(_contrl))
                        yield return childControl;
            }
        }
 
        public Form1()
        {
            InitializeComponent();
            IEnumerable<Control> allControls = AllControls(this);
            foreach (Control control in allControls)
                control.MouseMove += Form1_MouseMove;
        }
 
        private void Form1_MouseMove(object sender, MouseEventArgs e)
        {
            if (sender is Form)
                this.Text = string.Format("X: {0} Y: {1}", e.X, e.Y);
            else
            {
                POINT point = new POINT();
                if (GetCursorPos(out point))
                {
                    Point p = this.PointToClient(new Point(point.X, point.Y));
                    this.Text = string.Format("X: {0} Y: {1}", p.X, p.Y);
                }
            }
        }
    }
}

control.Location

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
 
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        public delegate int HookProc(int nCode, IntPtr wParam, IntPtr lParam);
 
        //Declare the hook
        static int hHook = 0;
 
        //Declare the mouse hook constant.
        //Для других типов hook, вы можете получить эти значения из Winuser.h в Microsoft SDK
        public const int WH_MOUSE = 7;
        //private System.Windows.Forms.Button button1;
 
        //Declare MouseHookProcedure as a HookProc type.
        HookProc MouseHookProcedure;
 
        //Declare the wrapper managed POINT class.
        [StructLayout(LayoutKind.Sequential)]
        public class POINT
        {
            public int x;
            public int y;
        }
 
        //Declare the wrapper managed MouseHookStruct class.
        [StructLayout(LayoutKind.Sequential)]
        public class MouseHookStruct
        {
            public POINT pt;
            public int hwnd;
            public int wHitTestCode;
            public int dwExtraInfo;
        }
 
        //This is the Import for the SetWindowsHookEx function.
        //Use this function to install a thread-specific hook.
        [DllImport("user32.dll", CharSet = CharSet.Auto,
         CallingConvention = CallingConvention.StdCall)]
        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn,
        IntPtr hInstance, int threadId);
 
        //This is the Import for the UnhookWindowsHookEx function.
        //Call this function to uninstall the hook.
        [DllImport("user32.dll", CharSet = CharSet.Auto,
         CallingConvention = CallingConvention.StdCall)]
        public static extern bool UnhookWindowsHookEx(int idHook);
 
        //This is the Import for the CallNextHookEx function.
        //Use this function to pass the hook information to the next hook procedure in chain.
        [DllImport("user32.dll", CharSet = CharSet.Auto,
         CallingConvention = CallingConvention.StdCall)]
        public static extern int CallNextHookEx(int idHook, int nCode,
        IntPtr wParam, IntPtr lParam);
 
        private void button1_Click(object sender, System.EventArgs e)
        {
            if (hHook == 0)
            {
                // Create an instance of HookProc.
                MouseHookProcedure = new HookProc(Form1.MouseHookProc);
 
                hHook = SetWindowsHookEx(WH_MOUSE,
                            MouseHookProcedure,
                            (IntPtr)0,
                            AppDomain.GetCurrentThreadId());
                //If the SetWindowsHookEx function fails.
                if (hHook == 0)
                {
                    MessageBox.Show("SetWindowsHookEx Failed");
                    return;
                }
                button1.Text = "UnHook Windows Hook";
            }
            else
            {
                bool ret = UnhookWindowsHookEx(hHook);
                //If the UnhookWindowsHookEx function fails.
                if (ret == false)
                {
                    MessageBox.Show("UnhookWindowsHookEx Failed");
                    return;
                }
                hHook = 0;
                button1.Text = "Set Windows Hook";
                this.Text = "Mouse Hook";
            }
        }
        public static int MouseHookProc(int nCode, IntPtr wParam, IntPtr lParam)
        {
            //Marshall the data from the callback.
            MouseHookStruct MyMouseHookStruct = (MouseHookStruct)Marshal.PtrToStructure(lParam, typeof(MouseHookStruct));
 
            if (nCode < 0)
            {
                return CallNextHookEx(hHook, nCode, wParam, lParam);
            }
            else
            {
                //Create a string variable that shows the current mouse coordinates.
                String strCaption = "x = " +
                        MyMouseHookStruct.pt.x.ToString("d") +
                            "  y = " +
                MyMouseHookStruct.pt.y.ToString("d");
                //You must get the active form because it is a static function.
                Form tempForm = Form.ActiveForm;
 
                //Set the caption of the form.
                tempForm.Text = strCaption;
                return CallNextHookEx(hHook, nCode, wParam, lParam);
            }
        }
    }
}