Question: I think it is not a good practice to close doors on one's face! My English is not good? It's ok. Tell me that. I'll accept it and I'll make an effort to make it better. I have let an incomplete answer because a bad educated person closed a door on my face!

Answer: 
Closing questions off topic questions is an integral part of the stack exchange format. If closing questions didn't prevent people from answering them then the act of closing questions would be meaningless.

There isn't a system to indicate that a question has pending draft answers and in the eyes of the community moderation process if the question *as written* has issues it shouldn't receive any answers. Unfortunately this occasionally results in race conditions where you can't submit an answer to a question that was closed while composing the draft.

When you gain sufficient reputation you can see who voted to close questions. I can't remember what the rep threshold is for seeing who voted to close a question. I can tell you that it was very likely 5 regular members of the community who voted to close it.
I've had a dozen or more questions over the years closed half-way through an answer I was writing. Once or twice I even thought the answer I was writing was some of my best work.

It happens - it's a consequence of the fact that 1-5 people voted to close the question before I could finish. It's not an insult to me - they don't (and can't) know that I'm trying to pound out an answer. It's just the way a self-moderated site works.

Welcome to the club. We meet on Thursdays.