I modified .rss file of the socket example, by just removing the default_input_mode of the RTEXT. Now it works fine with accepting the text data.
However, I don't think the HandleKeyEventL() implemented in UI is ever called. Since I press the keys and they are displayed on screen, but not even received at the other side. And even if I remove this funtion in the application, the keys been pressed still will be displayed on screen, of course no reception.
If anyone knows the reason and solution to this problem, please help. Thanks very much.