If you have a focus on a textbox but mousecursor not exactly hovering on it, mousecursor has default arrow shape or whatever you define.
At the time when you start typing, mousecursor hide itself and you see only blinking stick IBeam type cursor in the textbox.
Question: How to hold mousecursor on its initial position even if you start typing?
Interestingly enough: this doesn't happen in WPF apps.
This is a Windows setting.
Under Control Panel, go to Mouse and then you should see a setting similar to "Hide Pointer While Typing"
Far as I know, there's no way to do that. Even after turning off the Windows "Hide Pointer While Typing" setting, the cursor will disappear if it is positioned over not just the textbox, but the entire form.
There doesn't seem to be anything in the properties of either the textbox control or the form that affects this behaviour.
I'm going to answer the question. The side-effects and repercussions are your responsibility. Is there another way of doing it? I'm certain.
Create a "state" variable to hold the state of whether a user is typing or not. Textboxes have various events to let you know when someone is typing, EN_CHANGE, etc., that whole family of events and so on. Set state variable true when user is typing. False when not typing, EN_LOSTFOCUS, etc.
Trap mouse input through a PreProcessMessage event or PreTranslateMessage event, or any that seem appropriate.
Call "ShowCursor" or potentially "SetCursor" in the OnPaint event whilst the state variable is true. Yep, hairy, eh. Do not call it while the state variable is false.
Debug, debug, debug after this. HTH
If this is not clear post and I'll expand my answer.
Guys... That was ridiculously easy. In TextBox.KeyDown I have to move the Cursor every time to point where it was before..
Cursor.Position = new Point( oldX, oldY );
The only ugly thing here - if it's an animated cursor, animation starts everytime all over again. And also you can't type and move the mouse at the same time. That 's kind'a suck, on the other hand who cares? Winform apps tend to be uglier than WPF ones, isn't that true?