如何在richTextBox中添加新行而不在新行后留空格/空行？

Question

private void richTextBox1_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                string lastpadnum = padnumbers[padnumbers.Count - 1];
                int desiredLength = lastpadnum.Length;
                int nextnum = Convert.ToInt32(lastpadnum) + 1;
                string nextpadnum = nextnum.ToString().PadLeft(desiredLength, '0');
                padnumbers.Add(nextpadnum);
                richTextBox1.AppendText("\r\n" + nextpadnum);
            }
        }

This is working once if i scroll down to the bottom of the richtextbox and click on enter it will add a new line. If the last line was 191 the new one will be 192. Or if last one was 000191 the new one will be 000192.

But i have two problems:

The first is that this is working only if i click on enter after scrolled down to the bottom and adding new last line. But if i want to add a new line and give it a number somewhere in the middle between two existing lines ? How then i renumber the whole lines ? For example if i click on enter key between lines 0033 and 0035 then the new line is 0034 but line 0034 that is already exist should be now 0035 and 0035 will be 0036...

Second problem is that each time in the bottom i will click on enter it will make new line empty new line and then will add the line. I need the "\\r\\n" to make it new line but then next time i click enter it will first make new empty line. How can i avoid the empty line but that it will add a new line after the last one ?

Answer 1

For your first question if you press enter in middle line it will add you new lines anyway at the bottom, so 0034 that exist will be 0035. But if you need to do something with this line where the caret position is you can look at this post .

For your second problem I checked your code and you just need to remove the \\r\\n from your code because when you hit enter you adding new line. If you want to keep the \\r\\n you can use

   e.SuppressKeyPress=true;

This will disable the new line that the enter key make.