悬浮头部

Posted 2021-01-07 dingpeng

1.Activity代码：

public class Demo extends Activity {

    private LinearLayout invis;
    private LinearLayout invis2;
    private TextView mTVSuspension;
    private PullToRefreshListView mPullToRefreshListView;   //一个可以下拉刷新的listView对象
    private ArrayList<String> list = new ArrayList<String>(); //数据源
    private ListView listView; //普通的listView对象
    private View header1;
    private View header2;

    @Override
    protected void onCreate ( Bundle savedInstanceState ) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.demo);

        invis = (LinearLayout) findViewById(R.id.invis);
        mPullToRefreshListView = (PullToRefreshListView) findViewById(R.id.refreshListView);

        for (int i = 0; i < 50; i++) {
            list.add("data-----" + i);
        }

        listView = mPullToRefreshListView.getRefreshableView();

        mPullToRefreshListView.setMode(PullToRefreshBase.Mode.BOTH);
  
        header1 = View.inflate(this, R.layout.header1, null);
        listView.addHeaderView(header1);  
        header2 = View.inflate(this, R.layout.header2, null);
        invis2 = (LinearLayout) header2.findViewById(R.id.invis2);
        mTVSuspension = (TextView) header2.findViewById(R.id.tv_suspension);
        listView.addHeaderView(header2);  //添加头部，ListView条目中的悬浮部分

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick ( AdapterView<?> parent, View view, int position, long id ) {
                Toast.makeText(Demo.this, "第" + position + "item", Toast.LENGTH_SHORT).show();
            }
        });

        //实例化适配器对象
        listView.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, list));

        listView.setOnScrollListener(new AbsListView.OnScrollListener() {

            @Override
            public void onScrollStateChanged ( AbsListView view, int scrollState ) {
            }

            //方法onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) 内参数的介绍：
            // (1）AbsListView view 所监听的listView对象
            //（2）int firstVisibleItem 能看见的第一个item的位置
            //（3）int visibleItemCount 能看见的item的数量
            //（4）int totalItemCount 所有item的总数
            @Override
            public void onScroll ( AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount ) {
                if (firstVisibleItem >= 2) {  //第二个条目内容已经不显示
                    if (mTVSuspension.getParent() != invis) {
                        invis2.removeView(mTVSuspension);
                        invis.addView(mTVSuspension);
                    }
                } else {
                    if (mTVSuspension.getParent() != invis2) {
                        invis.removeView(mTVSuspension);
                        invis2.addView(mTVSuspension);
                    }
                }
            }
        });
    }


}

2.demo布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.handmark.pulltorefresh.library.PullToRefreshListView
        android:id="@+id/refreshListView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <LinearLayout
        android:id="@+id/invis"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:orientation="vertical">

    </LinearLayout>


</RelativeLayout>

3.header1布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <TextView
        android:id="@+id/texts"
        android:layout_width="match_parent"
        android:layout_height="130dp"
        android:background="#000"
        android:gravity="center"
        android:text="标题"
        android:textColor="#ffffff" />


</RelativeLayout>

4.header2布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:id="@+id/invis2"
        android:layout_width="match_parent"
        android:layout_height="50dp">

        <TextView
            android:id="@+id/tv_suspension"
            android:background="#ccedc7"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:gravity="center"
            android:text="悬浮部分" />
    </LinearLayout>

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:background="@mipmap/ic_launcher"/>

</LinearLayout>