Android SwipeRefreshLayout仿抖音app静态刷新

<android.support.v4.widget.SwipeRefreshLayout     android:id="@+id/sr1"     android:layout_width="match_parent"    android:layout_height="match_parent">     <ListView      android:id="@+id/lv"      android:layout_width="match_parent"      android:layout_height="wrap_content"/>    </android.support.v4.widget.SwipeRefreshLayout> 

public class ListViewActivity extends AppCompatActivity implements SwipeRefreshLayout.OnRefreshListener {  private SwipeRefreshLayout swipeRefreshLayout;  private ListView listView;  private List<String> list;  private ArrayAdapter adapter;   @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.activity_list_view);   swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.sr1);   swipeRefreshLayout.setOnRefreshListener(this);   list = new ArrayList<>();   list.add("ssss");   listView = (ListView) findViewById(R.id.lv);   adapter = new ArrayAdapter(this     , android.R.layout.simple_list_item_1     , android.R.id.text1     , list);   listView.setAdapter(adapter);  }   @Override  public void onRefresh() {   new Handler().postDelayed(new Runnable() {    @Override    public void run() {     swipeRefreshLayout.setRefreshing(false);     adapter.clear();     list.add("1111");     adapter.notifyDataSetChanged();    }   }, 1000);  } }