The problem that QLineEdit cannot be input when using QT VCP

Hello everyone
I recently used QT VCP to edit my interface. The progress is fairly normal, but a difficult problem has occurred recently.
When I use LineEdit, TextEdit and other input widgets in the interface. Run linuxcnc to open the interface, I cannot edit lineEdit, textEdit is the same.
I can get the focus, the mouse can click to get the focus, and I can see the frame when the focus is obtained, but I just can't input anything.
I tried replacing the input method to install fcix-qt5, but it didn't work.
Has anyone encountered this problem? Help
I use Ubuntu 18.04
Manually compile and install linuxcnc2.9
And QT5

This sounds like the keybinding function intercepting the keystrokes.
If you run qtvcp with -d and run linuxcnc from a terminal, you will probably see the debug code when you type.

If you don't require keyboard shortcuts you should be able to eliminate this problem pretty easily byt removing the function.
If you want keyboard short cuts then you need to tell the handler file what widgets should get keystrokes.

def processed_key_event__() in the handler file is what sets all this.

Chris

Thank you very much for your reply, I have solved the problem. As you said, there is a problem with the def processing_key_event__() function. Thank you very much for your help and best wishes to you.

thanks