Android实现ListView分页加载数据
本文实例为大家分享了ListView分页加载数据的具体代码，供大家参考，具体内容如下
FenyeActivity
package com.example.myapplication.fenye;
import androidx.appcompat.app.AppCompatActivity;
import android.app.ListActivity;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.widget.AbsListView;
import android.widget.Button;
import android.widget.ListView;
import com.example.myapplication.R;
import java.util.ArrayList;
public class FenyeActivity extends ListActivity implements AbsListView.OnScrollListener {
private ListView listView;
private int visibleLastIndex = 0; //最后的可视项索引
private int visibleItemCount; // 当前窗口可见项总数
private ListViewAdapter adapter;
private View loadMoreView;
private Button loadMoreButton;
private Handler handler = new Handler();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fenye);
loadMoreView = getLayoutInflater().inflate(R.layout.load_more, null);
loadMoreButton = (Button) loadMoreView.findViewById(R.id.loadMoreButton);
listView = getListView(); //获取id是list的ListView
listView.addFooterView(loadMoreView); //设置列表底部视图
initAdapter();
setListAdapter(adapter); //自动为id是list的ListView设置适配器
listView.setOnScrollListener(this); //添加滑动监听
}
/**
* 初始化适配器
*/
private void initAdapter() {
ArrayList<String> items = new ArrayList<String>();
for (int i = 0; i < 16; i++) {
items.add(String.valueOf(i + 1));
}
adapter = new ListViewAdapter(this, items);
}
/**
* 滑动时被调用
*/
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
this.visibleItemCount = visibleItemCount;
visibleLastIndex = firstVisibleItem + visibleItemCount - 1;
}
/**
* 滑动状态改变时被调用
*/
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
int itemsLastIndex = adapter.getCount() - 1; //数据集最后一项的索引
int lastIndex = itemsLastIndex + 1; //加上底部的loadMoreView项
if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE && visibleLastIndex == lastIndex) {
//如果是自动加载,可以在这里放置异步加载数据的代码
Log.e("wy", "loading...");
handler.postDelayed(new Runnable() {
@Override
public void run() {
loadData();
adapter.notifyDataSetChanged(); //数据集变化后,通知adapter
listView.setSelection(visibleLastIndex - visibleItemCount + 1); //设置选中项
loadMoreButton.setText("load more"); //恢复按钮文字
}
}, 1000);
}
}
/**
* 点击按钮事件
* @param view
*/
public void loadMore(View view) {
loadMoreButton.setText("loading..."); //设置按钮文字loading
handler.postDelayed(new Runnable() {
@Override
public void run() {
loadData();
adapter.notifyDataSetChanged(); //数据集变化后,通知adapter
listView.setSelection(visibleLastIndex - visibleItemCount + 1); //设置选中项
loadMoreButton.setText("load more"); //恢复按钮文字
}
}, 1000);
}
/**
* 模拟加载数据
*/
private void loadData() {
int count = adapter.getCount();
for (int i = count; i < count + 10; i++) {
adapter.addItem(String.valueOf(i + 1));
}
}
}
ListViewAdapter
package com.example.myapplication.fenye;
import java.util.List;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import com.example.myapplication.R;
public class ListViewAdapter extends BaseAdapter {
private List<String> items;
private LayoutInflater inflater;
public ListViewAdapter(Context context, List<String> items) {
this.items = items;
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
return items.size();
}
@Override
public Object getItem(int position) {
return items.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View view, ViewGroup parent) {
if (view == null) {
view = inflater.inflate(R.layout.list_fy_item, null);
}
TextView text = (TextView) view.findViewById(R.id.list_item_text);
if(null!=items){
text.setText(items.get(position));
}
return view;
}
/**
* 添加列表项
* @param item
*/
public void addItem(String item) {
items.add(item);
}
}
activity_fenye.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:paddingLeft="3dp"
android:paddingRight="3dp">
<ListView
android:id="@id/android:list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
list_fy_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:id="@+id/list_item_text"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="aa"
android:gravity="center"
android:textSize="20sp"
android:paddingTop="10dp"
android:paddingBottom="10dp"/>
</LinearLayout>
load_more.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<Button
android:id="@+id/loadMoreButton"
android:visibility="gone"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="load more"
android:onClick="loadMore"/>
</LinearLayout>
