private void _Event_ConversationInput_KeyDown(object sender, KeyEventArgs e) { if (e.Key == Key.Space) { if (ConversationInput.Text.Contains(":")) { var code = ConversationInput.Text.Substring(ConversationInput.Text.LastIndexOf(':')); var emoji = Ultilities.ConvertCodeToEmoji(code); if (emoji != null) { ConversationInput.Text = ConversationInput.Text.Replace(code, emoji); ConversationInput.SelectionStart = ConversationInput.Text.Length; } } } }