.NET Multiline Textbox Make Shift+Enter working instead of Enter key - textbox

Question

I have a Windows Form Multiline Textbox.
I want to use Shift+Enter Instead of using Enter key to make a new line in textbox, and the traditional Enter key will be used to focus on the next control.
I mean Shift+Enter will work exactly like Enter 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,...)
I've tried to override OnKeyDown, to insert newline on Shift+Enter, but it doesn't work as I expected.

Answer 1

you'll need to override OnKeyDown and check for enter key using the KeyDownEvent's KeyCode property.
If enter was pressed and the keydownevent's modifiers property does not equal Keys.Shift you'll need to suppress the key press. Here's the documentation on how to do that:
http://msdn.microsoft.com/en-us/library/system.windows.forms.keyeventargs.suppresskeypress(v=vs.110).aspx
If shift+enter was pressed you'll need to insert Environment.NewLine at the cursor position, then move the cursor after the inserted Environment.NewLine. Here's how to do that:
How to paste text in textbox current cursor?

Answer 2

Here is my implementation in VB .NET.
Regard to Maxlength of the textbox and current selected text
Protected Overrides Sub OnKeyDown(ByVal e As System.Windows.Forms.KeyEventArgs)
If (Me.Multiline AndAlso e.KeyData = (Keys.Shift Or Keys.Enter)) Then
Dim intRemainCharCount As Integer = Me.MaxLength - Me.Text.Length + Me.SelectedText.Length
'' Check if have enough space to place NewLine
If (Environment.NewLine.Length > intRemainCharCount) Then
MyBase.OnKeyDown(e)
Return
End If
Dim intPos = Me.SelectionStart
Me.Paste(Environment.NewLine)
'' Reset selection start (Reset cusor position)
Me.SelectionStart = intPos + Environment.NewLine.Length
e.Handled = True
e.SuppressKeyPress = True
Return
End If
MyBase.OnKeyDown(e)
End Sub

Answer 3

Change the property for Accept Return for the Multiline doesn't even require coding anything, unless you have an event listening to the KeyDown, in which case you can put a condition to check if the Textbox is focussed.