How to set the text change monitoring on Android

Text Change monitoring:

Username is an object of EditText

Username.addtextchangedlistener (New Textwatcher () {


@Override
public void ontextchanged (charsequence s, int start, int before, int count) {
The number of references means: S text content, start changes from the first few characters, before (oneself can test. I did not test), count changed the number of characters
TODO auto-generated Method Stub
LOG.I ("EditText", s.tostring ());
}


@Override
public void beforetextchanged (charsequence s, int start, int count,
int after) {
TODO auto-generated Method Stub
LOG.I ("EditText beforetextchanged", s.tostring ());


}


@Override
public void aftertextchanged (Editable s) {
LOG.I ("EditText aftertextchanged", s.tostring ());
TODO auto-generated Method Stub


}
});

How to set the text change monitoring on Android