@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); clickEvent = new ClickEvent(); viewHolder = ViewHolder.getInstance(); viewHolder.setTvOut((TextView) findViewById(R.id.tvOut)); viewHolder.setBtnPush((Button) findViewById(R.id.btnPush)); viewHolder.setBtnReload((Button) findViewById(R.id.btnReload)); viewHolder.getBtnPush().setOnClickListener(this); viewHolder.getBtnReload().setOnClickListener(this); }