Why new line takes two backspaces to erase c#

Question

This is an extension of a previously stated (and solved) problem (Unable to get desired output for keydown c#)

I two textboxes, that have to be synchronized based on what the user types in one of the textboxes.
Now, before you jump into thinking I could simply equate the textboxes, I shall tell you that that isn't my ultimate goal. So, copying text wouldn't work.
The problem:
The text comprises of newline, given by

//Next Line
if (e.KeyData == Keys.Enter)
   textBox2.Text += Environment.NewLine;

And when the user presses backspace, it erases the characters using

//Remove a character
if (e.KeyCode == Keys.Back && textBox2.TextLength != 0)
   textBox2.Text = textBox2.Text.Remove(textBox2.TextLength - 1, 1);

Simple enough, right? Here's the twist.
Every time I write something in the newline, and erase it to come back to the previous line, in the first textbox, it takes two backspaces to erase the newline and come back to the previous line, in the second textbox.

For example, assume the text is
Hello
Hi

Removing "Hi":
Hello

(The new line still exists, because I haven't yet tried removing it)

Now, if I want to remove the 'o' from "Hello", I'd have to normally press two back spaces and I'd have "Hell" (Which is what happens in the first textbox, where I am typing)
But, by doing so, the text in the second box is still "Hello". It takes me a 3rd backspace to remove 'o'.
At this point, my two textboxes are out of sync, because
Content in first textbox: "Hel"
Content in second textbox: "Hell"

So, please tell me why this is happening? And what I could possibly do to fix it.

What do you expect from: `var len = Environment.NewLine.Length;`? **1** or **2** ? — EZI, Aug 01 '15 at 16:46
not very clear of what is really happening,can you show some code and probably a clear example of when and what is happening? — terrybozzio, Aug 01 '15 at 16:53
@terrybozzio The code is in the link that I've specified in the early part of the question. As for an example, I've typed it down because taking screen shot for every step wouldn't be feasible exactly — Sanketh. K. Jain, Aug 01 '15 at 18:27

score 2 · Accepted Answer · answered Aug 01 '15 at 16:47

A new line may be one character. It may also be two.

It's called "Carriage Return" and "Line feed" from back in the days when we all used type writers. Two characters, one after another, symbolizing a line break.

You should take a debugger and check your string when you appended a new line. After what you described, I would not be surprised to see a 0x0d character followed by a 0x0a character.

Why new line takes two backspaces to erase c#

1 Answers1