这期内容当中小编将会给大家带来有关如何在Android应用中分批显示 ListView数据，文章内容丰富且以专业的角度为大家分析和叙述，阅读完这篇文章希望大家可以有所收获。
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Android ListView数据的分批显示
布局文件activity_call_safe2.xml
<?xml version="1.0" encoding="utf-8"?>
逻辑文件，实现页面的分页显示，监听ListView的滑动事件，滑动的时候就更新数据
CasllSafeActivity.java
package com.ldw.safe.Activity;
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import com.ldw.safe.R;
import com.ldw.safe.adapter.MyBaseAdapter;
import com.ldw.safe.bean.BlackNumberInfo;
import com.ldw.safe.db.dao.BlackNumberDao;
public class CallSafeActivity extends Activity {
private ListView list_view_callsafe;
private List blackNumberInfos;
private LinearLayout ll_pb;
private BlackNumberDao dao;
private CallSafeAdapter adapter;
private int totalNumber;//总的条数
private int mStartIndex = 0;//开始加载的位置
private int maxCount = 20;//每页加载多少数据
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_call_safe2);
initUi();
initData();
}
//初始化数据
private Handler handler = new Handler(){
@Override
public void handleMessage(Message msg) {
//数据初始化结束，关闭家在全的展示
ll_pb.setVisibility(View.INVISIBLE);
//防止适配器一直刷新
if(adapter == null){
adapter = new CallSafeAdapter(blackNumberInfos, CallSafeActivity.this);
//配置适配器
list_view_callsafe.setAdapter(adapter);
}else{
adapter.notifyDataSetChanged();
}
}
};
private EditText et_page_number;
//初始化数据
private void initData() {
//防止阻塞主线程，在子线程中初始化数据（后期数据会很多）
new Thread(){
@Override
public void run(){
dao = new BlackNumberDao(CallSafeActivity.this);
//一共有多少条数据
totalNumber = dao.getTotalNumber();
//分批加载数据
if(blackNumberInfos == null){
//第一次加载
blackNumberInfos = dao.findPar2(mStartIndex, maxCount);
}else{
//把后面的数据。追加到blackNumberInfos集合里面。防止黑名单被覆盖
blackNumberInfos.addAll(dao.findPar2(mStartIndex, maxCount));
}
handler.sendEmptyMessage(0);
}
}.start();
}
//初始化UI
private void initUi() {
ll_pb = (LinearLayout) findViewById(R.id.ll_pb);
//初始化的时候展示加载的圆圈
ll_pb.setVisibility(View.VISIBLE);
list_view_callsafe = (ListView) findViewById(R.id.list_view_callsafe);
//设置listView的滚动监听器
list_view_callsafe.setOnScrollListener(new OnScrollListener(){
//状态改变时候回调的方法
/*
* @param scrollState 表示滚动的状态
*AbsListView.OnScrollListener.SCROLL_STATE_IDLE 闲置状态
*AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL 手指触摸的时候的状态
*AbsListView.OnScrollListener.SCROLL_STATE_FLING 惯性
*/
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
switch (scrollState) {
case AbsListView.OnScrollListener.SCROLL_STATE_IDLE:
//获取到最后一条显示的数据条数
int lastVisiblePosition = list_view_callsafe.getLastVisiblePosition();
System.out.println("lastVisiblePosition==========" + lastVisiblePosition);
if(lastVisiblePosition == blackNumberInfos.size() - 1){//判断最后一个数据是不是每页显示的数据-1
// 加载更多的数据。 更改加载数据的开始位置
mStartIndex += maxCount;
if (mStartIndex >= totalNumber) {
Toast.makeText(getApplicationContext(),
"没有更多的数据了。", Toast.LENGTH_SHORT).show();
return;
}
initData();
}
break;
}
}
//listview滚动的时候调用的方法
//时时调用。当我们的手指触摸的屏幕的时候就调用
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
}
});
}
//对代码进行优化，继承自定义MyBaseAdapter，MyBaseAdapter继承自BaseAdapter封装一些常用的方法
private class CallSafeAdapter extends MyBaseAdapter{
private CallSafeAdapter(List lists, Context mContext){
super(lists, mContext);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
//谷歌推出的优化方案
ViewHolder holder;
if(convertView == null){
convertView = View.inflate(CallSafeActivity.this, R.layout.item_call_safe, null);
holder = new ViewHolder();
holder.tv_number = (TextView) convertView.findViewById(R.id.tv_number);
holder.tv_mode = (TextView) convertView.findViewById(R.id.tv_mode);
holder.iv_delete = (ImageView) convertView.findViewById(R.id.iv_delete);
convertView.setTag(holder);
}else{
holder = (ViewHolder) convertView.getTag();
}
holder.tv_number.setText(lists.get(position).getNumber());
String mode = lists.get(position).getMode();
if(mode.equals("1")){
holder.tv_mode.setText("电话和短信拦截");
}else if(mode.equals("2")){
holder.tv_mode.setText("电话拦截");
}else if(mode.equals("3")){
holder.tv_mode.setText("短信拦截");
}
final BlackNumberInfo info = lists.get(position);
//监听删除数据按钮，删除数据
holder.iv_delete.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
String number = info.getNumber();
boolean result = dao.delete(number);
if(result){
Toast.makeText(CallSafeActivity.this, "删除成功", Toast.LENGTH_SHORT).show();
lists.remove(info);
//更新ListView
adapter.notifyDataSetChanged();
}else{
Toast.makeText(CallSafeActivity.this, "删除失败", Toast.LENGTH_SHORT).show();
}
}
});
return convertView;
/*
//谷歌推出的优化方案
ViewHolder holder;
if(convertView == null){
convertView = View.inflate(CallSafeActivity.this, R.layout.item_call_safe, null);
holder = new ViewHolder();
holder.tv_number = (TextView) convertView.findViewById(R.id.tv_number);
holder.tv_mode = (TextView) convertView.findViewById(R.id.tv_mode);
convertView.setTag(holder);
}else{
holder = (ViewHolder) convertView.getTag();
}
holder.tv_number.setText(blackNumberInfos.get(position).getNumber());
String mode = blackNumberInfos.get(position).getMode();
if(mode.equals("1")){
holder.tv_mode.setText("电话和短信拦截");
}else if(mode.equals("2")){
holder.tv_mode.setText("电话拦截");
}else if(mode.equals("3")){
holder.tv_mode.setText("短信拦截");
}
return convertView;
*/
/*初步的优化
convertView = View.inflate(CallSafeActivity.this, R.layout.item_call_safe, null);
TextView tv_number = (TextView) convertView.findViewById(R.id.tv_number);
TextView tv_mode = (TextView) convertView.findViewById(R.id.tv_mode);
tv_number.setText(blackNumberInfos.get(position).getNumber());
String mode = blackNumberInfos.get(position).getMode();
if(mode.equals("1")){
tv_mode.setText("电话和短信拦截");
}else if(mode.equals("2")){
tv_mode.setText("电话拦截");
}else if(mode.equals("3")){
tv_mode.setText("短信拦截");
}
return convertView;
*/
/*传统的方式
View view = View.inflate(CallSafeActivity.this, R.layout.item_call_safe, null);
TextView tv_number = (TextView) view.findViewById(R.id.tv_number);
TextView tv_mode = (TextView) view.findViewById(R.id.tv_mode);
tv_number.setText(blackNumberInfos.get(position).getNumber());
String mode = blackNumberInfos.get(position).getMode();
if(mode.equals("1")){
tv_mode.setText("电话和短信拦截");
}else if(mode.equals("2")){
tv_mode.setText("电话拦截");
}else if(mode.equals("3")){
tv_mode.setText("短信拦截");
}
return view;
*/
}
}
static class ViewHolder{
TextView tv_number;
TextView tv_mode;
ImageView iv_delete;
}
}上述就是小编为大家分享的如何在Android应用中分批显示 ListView数据了，如果刚好有类似的疑惑，不妨参照上述分析进行理解。如果想知道更多相关知识，欢迎关注创新互联行业资讯频道。
本文标题：如何在Android应用中分批显示ListView数据
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