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Android ListView数据的分批显示功能

程序员文章站 2022-10-24 17:10:20
android listview数据的分批显示 布局文件activity_call_safe2.xml

android listview数据的分批显示

布局文件activity_call_safe2.xml

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical" >
  <relativelayout 
    android:layout_width="match_parent"
   android:layout_height="wrap_content"
    >
    <textview 
 style="@style/titlestyle"
   android:text="黑名单管理"
    />
    <button 
      android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignparentright="true"
    android:text="添加"
      />
  </relativelayout>
  <framelayout 
    android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:layout_weight="11"
    >
    <linearlayout 
      android:id="@+id/ll_pb"
      android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:visibility="invisible"
    android:orientation="vertical"
    >
    <progressbar
      android:layout_width="wrap_content"
    android:layout_height="wrap_content"
      />
    <textview 
      android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="玩命加载中..."
      />
    </linearlayout>
   <include 
     android:id="@+id/list_view_callsafe"
     layout="@layout/list_view_callsafe"/>
  </framelayout>
</linearlayout>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<blacknumberinfo> 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<blacknumberinfo>{
 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;
 }
}

以上所述是小编给大家介绍的android listview数据的分批显示功能，希望对大家有所帮助

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