As Hans Passant said
Ctrl+A doesn't actually work in that mode, you have to implement it yourself. Not hard with a KeyDown event handler.
To Implement what you want, you can use the KeyDown
event of the textbox
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
if (e.Control)
{
if (e.KeyCode == Keys.A)
{
textBox1.SelectAll();
}
if (e.KeyCode == Keys.Back)
{
e.SuppressKeyPress = true;
int selStart = textBox1.SelectionStart;
while (selStart > 0 && textBox1.Text.Substring(selStart - 1, 1) == " ")
{
selStart--;
}
int prevSpacePos = -1;
if (selStart != 0)
{
prevSpacePos = textBox1.Text.LastIndexOf(' ', selStart - 1);
}
textBox1.Select(prevSpacePos + 1, textBox1.SelectionStart - prevSpacePos - 1);
textBox1.SelectedText = "";
}
}
}