Question

I’ve got a System.Windows.Forms.TextBox that is multi-line but it doesn’t accept commands like Control-A and Control-Backspace.

Control-A does nothing and Control-Backspace inserts a box character.

The “Shortcuts Enabled” property is set to true.

Answer 1

From MSDN on the ShortcutsEnabled property:

The TextBox control does not support the CTRL+A shortcut key when the Multiline property value is true.

You’ll have to implement it yourself.

Something like this should work:

    private void textBox1_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.Control & e.KeyCode == Keys.A)
        {
            textBox1.SelectAll();
        }
        else if (e.Control & e.KeyCode == Keys.Back)
        {
            SendKeys.SendWait("^+{LEFT}{BACKSPACE}");
        }
    }