Console Application - WriteLine above current working line

Question

I have seen a few other posts very similar to this one, but the answers they give are not correctly answering the question. Sorry if there is something hidden away that I co

Answer 1

You can use carriage-return (\r, or U+000D) to return the cursor to the start of the current line, and then overwrite what's there. Something like

// A bunch of spaces to clear the previous output
Console.Write("\r                               ");
Console.WriteLine("\rI just waited 5 seconds");
Console.Write("Please input something: ");

However, if the user has started typing already this won't work anymore (as you may not overwrite all they have typed, and they will lose what they've typed on the screen, although it's still there in memory.

To properly solve this you actually need to modify the console's character buffer. You have to move everything above the current line one line up, and then insert your message. You can use Console.MoveBufferArea to move an area up. Then you need to save the current cursor position, move the cursor to the start of the line above, write your message, and reset the cursor position again to the saved one.

And then you have to hope that the user doesn't type while you're writing your message, because that would mess things up. I'm not sure you can solve that while using ReadLine, though, as you cannot temporarily lock something while ReadLine is active. To properly solve that you may have to write your own ReadLine alternative that reads individual keypresses and will lock on a common object when writing the resulting character to avoid having two threads writing to the console at the same time.