How can I disable mouse input completely?

Okay, so anyone who looks this up, here is the way to disable your mouse. This script only disables left click because it's a semi-dangerous thing to do. This disables it just for your games application window:

Firstly, make sure you understand that you can stop your application in the editor with Ctrl + P. That's kind of important if you're disable mouse buttons.

If you want to specify which buttons to disable, you edit this part here:

     if (MouseMessages.WM_LBUTTONDOWN == (MouseMessages)wParam)
     {
            return (IntPtr)1;
     }

When that part returns 1; It's stopping the mouse event message from getting to your applications window, and thusly the application doesn't process a mouse click.

 public class Mouse
 {
  
     #if UNITY_STANDALONE_WIN
     
     public WindowsLowLevelHook windowsLowLevelHook = new WindowsLowLevelHook();
     
     public void DisableClicks()
     {
         windowsLowLevelHook.Enable();
     }
     public void EnableClicks()
     {
         windowsLowLevelHook.Disable();
     }

     public class WindowsLowLevelHook
     {
         public bool enabled = false;

         public delegate IntPtr HookProc(int nCode, IntPtr wParam, IntPtr lParam);
         public HookProc hookProc;
         
         public delegate void MouseHookCallback(MOUSEHOOKSTRUCT mouseHookStruct);
         
         #region Events
         public event MouseHookCallback LeftButtonDown;
         public event MouseHookCallback LeftButtonUp;
         public event MouseHookCallback RightButtonDown;
         public event MouseHookCallback RightButtonUp;
         public event MouseHookCallback MouseMove;
         public event MouseHookCallback MouseWheel;
         public event MouseHookCallback DoubleClick;
         public event MouseHookCallback MiddleButtonDown;
         public event MouseHookCallback MiddleButtonUp;
         #endregion
         
         public IntPtr hookID = IntPtr.Zero;
         public void Enable()
         {
             hookProc = MouseProc;
             hookID = SetHook(hookProc);
             enabled             = true;
         }
         public void Disable()
         {
             if (hookID == IntPtr.Zero)
                 return;

             UnhookWindowsHookEx(hookID);
             hookID                  = IntPtr.Zero;
             enabled                 = false;
         }
         ~WindowsLowLevelHook()
         {
             Enable();
         }

         private IntPtr SetHook(HookProc hookProc)
         {
             using (ProcessModule module = Process.GetCurrentProcess().MainModule)
                 return SetWindowsHookEx(WH_MOUSE, hookProc, GetModuleHandle(module.ModuleName), GetCurrentThreadId());
         }

         private IntPtr MouseProc(int nCode, IntPtr wParam, IntPtr lParam)
         {
             MOUSEHOOKSTRUCT lParamStruct = (MOUSEHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MOUSEHOOKSTRUCT));
             
             if (nCode >= 0)
             {

                 if (MouseMessages.WM_LBUTTONDOWN == (MouseMessages)wParam)
                 {
                     return (IntPtr)1;
                 }


             }
             return CallNextHookEx(hookID, nCode, wParam, lParam);
         }

         #region WinAPI
         private const int WH_MOUSE = 7;

         private enum MouseMessages
         {
             WM_LBUTTONDOWN = 0x0201,
             WM_LBUTTONUP = 0x0202,
             WM_MOUSEMOVE = 0x0200,
             WM_MOUSEWHEEL = 0x020A,
             WM_RBUTTONDOWN = 0x0204,
             WM_RBUTTONUP = 0x0205,
             WM_LBUTTONDBLCLK = 0x0203,
             WM_MBUTTONDOWN = 0x0207,
             WM_MBUTTONUP = 0x0208
         }

         private Int32 GetWindowThreadProcessID(IntPtr hwnd)
         {
             Int32 pid = 1;
             GetWindowThreadProcessId(hwnd, out pid);
             return pid;
         }

         [StructLayout(LayoutKind.Sequential)]
         public struct POINT
         {
             public int x;
             public int y;
         }
         
         [StructLayout(LayoutKind.Sequential)]
         public struct MOUSEHOOKSTRUCT
         {
             public POINT pt;
             public IntPtr hwnd;
             public uint wHitTestCode;
             public IntPtr dwExtraInfo;
         }
         

         [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
         private static extern IntPtr SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hMod, Int32 dwThreadId);

         [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
         [return: MarshalAs(UnmanagedType.Bool)]
         public 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);

         [DllImport("kernel32.dll")]
         private static extern Int32 GetCurrentThreadId();

         #endregion
     }


     #endif

 }

Did you try Script Reference: Cursor?

     Cursor.visible = false;
     Cursor.lockState = CursorLockMode.Locked;

Well it seems to fix this you need to get inside the button class (or whatever UI you dont want to access with mouse) and go through all OnMouse functions.

The ones that exist in the button class is:

• OnMouseDown()

• OnMouseDrag()

• OnMouseEnter()

• OnMouseExit()

• OnMouseOver()

• OnMouseUp()

• OnMouseUpAsButton()

You will need to access all instances of this class in your ingame and make sure these functions arent called cause they seem to control mouse input when it comes to UI.

EDIT: My best bet is to create a second button class. It is identical but you can edit it. Remove all functions that involves mouse input in the new one. Assign it to your buttons and remove the old one. I dont know where you can get the button script, just google it i guess