Android SmartRefreshLayout实现淘宝二楼

SmartRefreshLayout：https://github.com/scwang90/SmartRefreshLayout

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".Main25Activity">

    <com.scwang.smartrefresh.layout.SmartRefreshLayout
        android:id="@+id/refreshLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clipChildren="false"
        app:srlAccentColor="@android:color/white">

        <com.scwang.smartrefresh.layout.header.TwoLevelHeader
            android:id="@+id/header"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <ImageView
                android:id="@+id/second_floor"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:contentDescription="@string/app_name"
                android:scaleType="centerCrop"
                android:src="@mipmap/image_second_floor" />

            <FrameLayout
                android:id="@+id/second_floor_content"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:alpha="0"
                android:background="#fff">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:contentDescription="@string/app_name"
                    android:gravity="center"
                    android:scaleType="centerCrop"
                    android:text="二楼"
                    android:textColor="#000000" />
            </FrameLayout>

            <com.scwang.smartrefresh.layout.header.ClassicsHeader
                android:id="@+id/classics"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
        </com.scwang.smartrefresh.layout.header.TwoLevelHeader>


        <ScrollView
            android:id="@+id/scrollView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="#fff"
            android:fillViewport="true"
            android:overScrollMode="never">

            <RelativeLayout
                android:id="@+id/contentPanel"
                android:layout_width="match_parent"
                android:layout_height="wrap_content">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:adjustViewBounds="true"
                    android:contentDescription="@string/app_name"
                    android:gravity="center"
                    android:text="内容主题"
                    android:textColor="#000"
                    android:textSize="20dp" />

            </RelativeLayout>
        </ScrollView>

        <com.scwang.smartrefresh.layout.header.ClassicsHeader
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    </com.scwang.smartrefresh.layout.SmartRefreshLayout>

</FrameLayout>

public class Main25Activity extends AppCompatActivity {
    private TwoLevelHeader header;
    private RefreshLayout refreshLayout;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main25);
        initView();

        refreshLayout.setOnMultiPurposeListener(new SimpleMultiPurposeListener(){
            @Override
            public void onLoadMore(@NonNull RefreshLayout refreshLayout) {
                Toast.makeText(getApplication(),"上拉加载",Toast.LENGTH_SHORT).show();
                refreshLayout.finishLoadMore(2000);
            }

            @Override
            public void onRefresh(@NonNull RefreshLayout refreshLayout) {
                Toast.makeText(getApplication(),"下拉刷新",Toast.LENGTH_SHORT).show();
                refreshLayout.finishRefresh(2000);
            }

            @Override
            public void onStateChanged(@NonNull RefreshLayout refreshLayout, @NonNull RefreshState oldState, @NonNull RefreshState newState) {
                if (oldState == RefreshState.TwoLevel){
                    findViewById(R.id.second_floor_content).animate().alpha(0).setDuration(1000);
                }
            }
        });

        header.setOnTwoLevelListener(new OnTwoLevelListener() {
            @Override
            public boolean onTwoLevel(@NonNull RefreshLayout refreshLayout) {
                Toast.makeText(getApplication(),"打开二楼",Toast.LENGTH_SHORT).show();
                findViewById(R.id.second_floor_content).animate().alpha(1).setDuration(2000);
                return true;
            }
        });
    }

    private void initView() {
        header=findViewById(R.id.header);
        refreshLayout = findViewById(R.id.refreshLayout);
    }
}