title: .NET Multiline Textbox Make Shift+Enter working instead of Enter key
body: <p>I have a Windows Form Multiline Textbox.
  I want to use <kbd>Shift</kbd>+<kbd>Enter</kbd> Instead of using Enter key to make a new line in textbox, and the traditional <kbd>Enter</kbd> key will be used to focus on the next control.
  I mean <kbd>Shift</kbd>+<kbd>Enter</kbd> will work exactly like <kbd>Enter</kbd> key on normal multiline textbox (Regard to textbox maxlength --> So you cant enter newline, or current selected text will be delete when you insert newline,...)</p>
  
  <p>I've tried to override OnKeyDown, to insert newline on <kbd>Shift</kbd>+<kbd>Enter</kbd>, but it doesn't work as I expected.</p>