ListView下拉加载更多练习

来源：互联网发布：java redis缓存数据库编辑：程序博客网时间：2024/05/18 01:31

1：自定义尾部

新建一个尾部布局:

<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:layout_width="match_parent"

android:orientation="horizontal"

android:id="@+id/load_layout"

android:gravity="center"

android:layout_height="wrap_content">

<ProgressBar

android:layout_width="wrap_content"

android:layout_height="wrap_content"

style="@style/Base.Widget.AppCompat.ProgressBar"

<TextView

android:layout_width="wrap_content"

android:textSize="15sp"

android:layout_height="wrap_content"

android:text="正在加载..."/>

</LinearLayout>

自定义一个LoadlistView继承Listview

实体bean自己完成

public class Loadlistview extends ListView implements AbsListView.OnScrollListener {

View foote;//底部

int totalItemCount;//总数量

int lastItem;//最后的数量

boolean isLoading;//如果在加载

LoadListtener loadListtener;

public Loadlistview(Context context) {

super(context);

initView(context);

}

public Loadlistview(Context context, AttributeSet attrs) {

super(context, attrs);

initView(context);

}

public Loadlistview(Context context, AttributeSet attrs, int defStyle) {

super(context, attrs, defStyle);

initView(context);

}

//添加底部加载提示布局

private void initView(Context context) {

LayoutInflater inflater = LayoutInflater.from(context);

foote = inflater.inflate(R.layout.loadfooter_layout, null);

foote.findViewById(R.id.load_layout).setVisibility(View.GONE);//设置初始为隐藏

this.addFooterView(foote);

this.setOnScrollListener(this);

}

//监听下拉操作，

@Override

public void onScrollStateChanged(AbsListView view, int scrollState) {

if (totalItemCount == lastItem && scrollState == SCROLL_STATE_IDLE) {

if(!isLoading){

isLoading=true;

foote.findViewById(R.id.load_layout).setVisibility(View.VISIBLE);//设置初始为隐藏

loadListtener.onLoad();//滑动到最底层的时候调用此方法

}

@Override

public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {

//四个参数为：第一个可见item，第二个可见item，可见item数量，总数量。

this.lastItem = firstVisibleItem + visibleItemCount; //最后一个item等于第一个item+可见item

this.totalItemCount = totalItemCount;

}

//通过这个方法把接口设置进加载数据中

public void setInterface(LoadListtener loadListtener){

this.loadListtener=loadListtener;

}

//加载更多数据的回调接口

public interface LoadListtener{

public void onLoad();

}

//加载完毕后关闭加载底部

public void loadComplte(){

isLoading=false;

foote.findViewById(R.id.load_layout).setVisibility(View.GONE);

}

在主方法中使用自定义的Loadlistview

public class HotelOrderActivity extends Activity implements Loadlistview.LoadListtener {

private Loadlistview mListView;

private LinearLayout back;

private HotelAdpter mAdapter;

private List<HotelOrderBean> mlist = new ArrayList<HotelOrderBean>();

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.hotelorder_activity);

back = (LinearLayout) findViewById(R.id.back);

back.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

finish();

}

});

getData();

showListView(mlist);

mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

@Override

public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

Intent intent = new Intent(HotelOrderActivity.this, HotelDetalisActivity.class);

startActivity(intent);

}

});

}

private void showListView(List<HotelOrderBean> mlist) {

//适配器是空就set数据，如果不是空，调用适配器中加载更多的方法

if (mAdapter == null) {

mListView = (Loadlistview) findViewById(R.id.hotel_listview);

mListView.setInterface(this);

mAdapter = new HotelAdpter(this, mlist);

mListView.setAdapter(mAdapter);

} else {

mAdapter.onDataChange(mlist);

}

private void getData() {

for (int i = 0; i < 10; i++) {

HotelOrderBean ho = new HotelOrderBean();

ho.name = "皇家假日酒店" + i;

mlist.add(ho);

}

private void LoadData() {

for (int i = 0; i < 4; i++) {

HotelOrderBean ho = new HotelOrderBean();

ho.name = "更多假日酒店" + i;

mlist.add(ho);

}

//实现接口重写onLoad接口，获取更多数据，通知ListView更新数据

@Override

public void onLoad() {

//加载太快

Handler handler =new Handler();

handler.postDelayed(new Runnable() {

@Override

public void run() {

LoadData();

showListView(mlist);

mListView.loadComplte();//调用如果滑动到最底部的方法，说明加载完毕

}

}, 1800);

}

自定义适配器：

private class HotelAdpter extends BaseAdapter {

private List<HotelOrderBean> mlist;

private LayoutInflater mInflater;

//数据变化时调用，刷新界面

public void onDataChange(List<HotelOrderBean> mlist) {

this.mlist = mlist;

this.notifyDataSetChanged();

}

public HotelAdpter(Context context, List<HotelOrderBean> list) {

mlist = list;

mInflater = LayoutInflater.from(context);

}

@Override

public int getCount() {

return mlist.size();

}

@Override

public Object getItem(int position) {

return mlist.get(position);

}

@Override

public long getItemId(int position) {

return position;

}

@Override

public View getView(int position, View convertView, ViewGroup parent) {

if (convertView == null) {

convertView = mInflater.inflate(R.layout.hotelorder_listview_item, null);

}

TextView tx = (TextView) convertView.findViewById(R.id.hotelname);

HotelOrderBean ho = mlist.get(position);

tx.setText(ho.name);

return convertView;

}

总结：首先给Listview 添加尾部，设置滑动监听事件，滑动到尾部的时候，尾部布局才出现（ this.lastItem =
firstVisibleItem + visibleItemCount; //最后一个item等于第一个item+可见item

this.totalItemCount = totalItemCount;

）。
实现回调接口中的onLoad()方法 ,在onLoad中实现加载更多数据方法。

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