How to track mouse X/Y position and print it to a label? [duplicate]

Answer 1

You need to set a Windows hook in order to achieve this. The MSDN article How to set a Windows hook in Visual C# .NET shows how to set a mouse hook.

I tried it, it captures the mouse all over the form, even when the mouse cursor is over a control.

Answer 2

Here is the msdn documentation on system level mouse event handling calls (low level mouse proc).

Here is an example of using low level mouse procs to change the scroll event.

In the answer in the second link use WM_MOUSEMOVE from here instead of WM_MOUSEWHEEL.

One thing to note: for this program to continue to capture mouse events when the mouse is over a program with elevated privileges, this program will have to be launch with elevated privileges.

Code (not tested):

using System;

using System.Diagnostics;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace CatchMouseMove
{
    class InterceptMouse
    {
        const int INPUT_MOUSE = 0;
        const int MOUSEEVENTF_WHEEL = 0x0800;
        const int WH_MOUSE_LL = 14; 


        private static LowLevelMouseProc _proc = HookCallback;
        private static IntPtr _hookID = IntPtr.Zero;

        public static void Main()
        {
            _hookID = SetHook(_proc);

            if (_hookID == null)
            {
                MessageBox.Show("SetWindowsHookEx Failed");
                return;
            }
            Application.Run();
            UnhookWindowsHookEx(_hookID);
        }

        private static IntPtr SetHook(LowLevelMouseProc proc)
        {
            using (Process curProcess = Process.GetCurrentProcess())
            using (ProcessModule curModule = curProcess.MainModule)
            {
                return SetWindowsHookEx(WH_MOUSE_LL, proc,
                    GetModuleHandle(curModule.ModuleName), 0);
            }
        }

        private delegate IntPtr LowLevelMouseProc(int nCode, IntPtr wParam, IntPtr lParam);

        private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
        {
            int xPos = 0;
            int yPos = 0;

            if (nCode >= 0 && MouseMessages.WM_MOUSEMOVE == (MouseMessages)wParam)
            {    
                xPos = GET_X_LPARAM(lParam); 
                yPos = GET_Y_LPARAM(lParam);

                //do stuff with xPos and yPos
            }
            return CallNextHookEx(_hookID, nCode, wParam, lParam);
        }


        private enum MouseMessages
        {
            WM_MOUSEMOVE = 0x0200
        }

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

        [StructLayout(LayoutKind.Sequential)]
        private struct MSLLHOOKSTRUCT
        {
            public POINT pt;
            public int mouseData;
            public int flags;
            public int time;
            public IntPtr dwExtraInfo;
        }

        public struct INPUT
        {
            public int type;
            public MOUSEINPUT mi;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct MOUSEINPUT
        {
            public int dx;
            public int dy;
            public int mouseData;
            public uint dwFlags;
            public int time;
            public int dwExtraInfo;
        }



        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr SetWindowsHookEx(int idHook,
            LowLevelMouseProc lpfn, IntPtr hMod, uint dwThreadId);

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool UnhookWindowsHookEx(IntPtr hhk);

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
            IntPtr wParam, IntPtr lParam);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr GetModuleHandle(string lpModuleName);

    }

}

Answer 3

You can use the EventArgs of the MouseMove event, because it holds the mouse coordinates. From there you can easily set the text property of the label to the X or Y coordinate you will take from e (the MouseMove EventArgs).

private void Form_MouseMove(object sender, MouseEventArgs e)
{
    // Update the mouse coordinates displayed in the textbox.
    myTextBox.Text = e.Location.ToString();
}