Suppress mouse-movement

I need to freeze the windows mouse cursor on the screen, so it stays hovered over a specific UI element. While the mouse is in this frozen state, I would still like to be able to interact with the UI using a "fake" mouse pointer.

Currently, I've got a low level mouse hook that prevents WM_MOUSEMOVE messages from being passed along, effectively sto开发者_StackOverflow中文版pping all real mouse movement. However, when I don't pass along the updated coordinates, windows actually sends me the old coordinates in a separate WM_MOUSEMOVE message, as if to correct for the fact that the mouse didn't move.

Any idea on either how to prevent Windows from sending me these corrected coordinates, or another approach of how I can freeze the actual mouse curosr and still allow the physical mouse to control a "Fake" cursor?

You can suppress mouse cursor movement by using DirectInput exclusive mode. You should acquire mouse input device when cursor movement must be suppressed. This will block windows cursor movement but you can get messages for your fake cursor using DirectInput API.

If you move the mouse cursor position in response to a WM_MOUSEMOVE message, to put the mouse back to where you want it, you will get another mouse move message because the mouse has been moved again (because you moved it). To stop this, don't set the mouse position if it is already in the right place.

You may also want to clip the mouse position to your window and get exclusive access to it.

Why don't you just draw an image of the cursor at the place you want it frozen, then set the real mouse cursor to be hidden (Cursor.Hide IIRC).

It's not clear to me what you are trying to do, perhaps making a tutorial for your app and you want to show mouse movements, etc. Perhaps this library will be useful:

http://www.codeproject.com/KB/system/globalmousekeyboardlib.aspx