如何监听textview 状态的变化。。。textview被更改的变化

list_show.addTextChangedListener(new TextWatcher() {
   
   @Override
   public void onTextChanged(CharSequence s, int start, int before, int count) {
    // TODO Auto-generated method stub
    
   }
   
   @Override
   public void beforeTextChanged(CharSequence s, int start, int count,
     int after) {
    // TODO Auto-generated method stub
    
   }
   
   @Override
   public void afterTextChanged(Editable s) {
    // TODO Auto-generated method stub
//    Toast.makeText(SearchListActivity.this, "选中1", 0).show();
       }
  

});