How can I know when an EditText loses focus?

Implement onFocusChange of setOnFocusChangeListener and there’s a boolean parameter for hasFocus. When this is false, you’ve lost focus to another control.

 EditText txtEdit = (EditText) findViewById(R.id.edittxt);

 txtEdit.setOnFocusChangeListener(new OnFocusChangeListener() {          
        @Override
        public void onFocusChange(View v, boolean hasFocus) {
            if (!hasFocus) {
               // code to execute when EditText loses focus
            }
        }
    });