Skipped pits in Android development--button not responding to click events

Yesterday encountered a headache problem, on the phone button events are normal, but on the tablet (horizontal display status), button click event does not respond, the code is simplified as follows:

public class Test extends Activity implements onclicklistener{

Private Button Testbutton = null;

@Override
protected void OnCreate (Bundle savedinstancestate) {
TODO auto-generated Method Stub
Super.oncreate (savedinstancestate);
Setcontentview (R.layout.activity_main);
Testbutton = (Button) This.findviewbyid (r.id.button_test);
Testbutton.setonclicklistener (this);
}

@Override
public void onconfigurationchanged (Configuration newconfig) {
TODO auto-generated Method Stub
Super.onconfigurationchanged (Newconfig);
Setcontentview (R.layout.activity_main);
}

@Override
public void OnClick (View v) {
TODO auto-generated Method Stub
Switch (V.getid ()) {
Case R.id.button_test:
Toast.maketext (This, "button click", Toast.length_short). Show ();
Break

Default
Break
}
}

}

Did you see the red part? Because the layout was reloaded on a horizontal screen, but the controls were not reinitialized, the equivalent of not registering the event, the click would be invalid.

Skipped pits in Android development--button not responding to click events