android自带下拉刷新SwipeRefreshLayout

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.SwipeRefreshLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:id="@+id/swipeLayout" >
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

</android.support.v4.widget.SwipeRefreshLayout>

public class MainActivity extends AppCompatActivity {
    SwipeRefreshLayout swipeRefreshLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        swipeRefreshLayout = (SwipeRefreshLayout)findViewById(R.id.swipeLayout);
        swipeRefreshLayout.setColorSchemeResources(R.color.colorAccent,
                R.color.colorPrimary,
                R.color.colorPrimary,
                R.color.colorPrimaryDark);
        swipeRefreshLayout.setSize(SwipeRefreshLayout.DEFAULT);;
        swipeRefreshLayout.setProgressViewOffset(true, 0, 200);
        swipeRefreshLayout.setProgressViewEndTarget(true, 100);
        swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                           sleep(3000);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        mHandler.sendEmptyMessage(1);
                    }
                }).start();
            }
        });}
        //handler
        @SuppressLint("HandlerLeak")
        Handler mHandler = new Handler(){
            @Override
            public void handleMessage(Message msg) {
                super.handleMessage(msg);
                switch (msg.what) {
                    case 1:
                        Toast.makeText(MainActivity.this, "刷新成功", Toast.LENGTH_SHORT).show();
                        swipeRefreshLayout.setRefreshing(false);
                        break;
                }
            }
        };
    }