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如何在Android應(yīng)用中分批顯示 ListView數(shù)據(jù)

發(fā)布時間：2020-12-03 15:06:09 來源：億速云 閱讀：216 作者：Leah 欄目：移動開發(fā)

這期內(nèi)容當中小編將會給大家?guī)碛嘘P(guān)如何在Android應(yīng)用中分批顯示 ListView數(shù)據(jù)，文章內(nèi)容豐富且以專業(yè)的角度為大家分析和敘述，閱讀完這篇文章希望大家可以有所收獲。

Android ListView數(shù)據(jù)的分批顯示

布局文件activity_call_safe2.xml

<&#63;xml version="1.0" encoding="utf-8"&#63;>
<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 
 
   android:text="黑名單管理"
    />
    <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="玩命加載中..."
      />
    </LinearLayout>
   <include 
     android:id="@+id/list_view_callsafe"
     layout="@layout/list_view_callsafe"/>
  </FrameLayout>
</LinearLayout>邏輯文件，實現(xiàn)頁面的分頁顯示，監(jiān)聽ListView的滑動事件，滑動的時候就更新數(shù)據(jù)

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;//總的條數(shù)
 private int mStartIndex = 0;//開始加載的位置
 private int maxCount = 20;//每頁加載多少數(shù)據(jù)
 @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_call_safe2);
    initUi();
    initData();
 }
 //初始化數(shù)據(jù)
 private Handler handler = new Handler(){
 @Override
    public void handleMessage(Message msg) {
  //數(shù)據(jù)初始化結(jié)束，關(guān)閉家在全的展示
  ll_pb.setVisibility(View.INVISIBLE);
  //防止適配器一直刷新
  if(adapter == null){
  adapter = new CallSafeAdapter(blackNumberInfos, CallSafeActivity.this);
  //配置適配器
  list_view_callsafe.setAdapter(adapter);
  }else{
   adapter.notifyDataSetChanged();
  }
 }
 };
 private EditText et_page_number;
 //初始化數(shù)據(jù)
 private void initData() {
 //防止阻塞主線程，在子線程中初始化數(shù)據(jù)（后期數(shù)據(jù)會很多）
 new Thread(){
  @Override
  public void run(){
  dao = new BlackNumberDao(CallSafeActivity.this);
   //一共有多少條數(shù)據(jù)
     totalNumber = dao.getTotalNumber();
  //分批加載數(shù)據(jù)
     if(blackNumberInfos == null){
      //第一次加載
      blackNumberInfos = dao.findPar2(mStartIndex, maxCount);
     }else{
      //把后面的數(shù)據(jù)。追加到blackNumberInfos集合里面。防止黑名單被覆蓋
      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);
    //初始化的時候展示加載的圓圈
    ll_pb.setVisibility(View.VISIBLE);
 list_view_callsafe = (ListView) findViewById(R.id.list_view_callsafe);
 //設(shè)置listView的滾動監(jiān)聽器
 list_view_callsafe.setOnScrollListener(new OnScrollListener(){
      //狀態(tài)改變時候回調(diào)的方法
      /*
       * @param scrollState 表示滾動的狀態(tài)
       *AbsListView.OnScrollListener.SCROLL_STATE_IDLE 閑置狀態(tài)
       *AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL 手指觸摸的時候的狀態(tài)
       *AbsListView.OnScrollListener.SCROLL_STATE_FLING 慣性
       */
  @Override
  public void onScrollStateChanged(AbsListView view, int scrollState) {
        switch (scrollState) {
        case AbsListView.OnScrollListener.SCROLL_STATE_IDLE:
          //獲取到最后一條顯示的數(shù)據(jù)條數(shù)
          int lastVisiblePosition = list_view_callsafe.getLastVisiblePosition();
          System.out.println("lastVisiblePosition==========" + lastVisiblePosition);
            if(lastVisiblePosition == blackNumberInfos.size() - 1){//判斷最后一個數(shù)據(jù)是不是每頁顯示的數(shù)據(jù)-1
              // 加載更多的數(shù)據(jù)。 更改加載數(shù)據(jù)的開始位置
              mStartIndex += maxCount;
              if (mStartIndex >= totalNumber) {
                Toast.makeText(getApplicationContext(),
                    "沒有更多的數(shù)據(jù)了。", Toast.LENGTH_SHORT).show();
                return;
              }
              initData();
            }
          break;
      }
  }
  //listview滾動的時候調(diào)用的方法
      //時時調(diào)用。當我們的手指觸摸的屏幕的時候就調(diào)用
  @Override
  public void onScroll(AbsListView view, int firstVisibleItem,
   int visibleItemCount, int totalItemCount) {
  // TODO Auto-generated method stub
  }
 });
 }
 //對代碼進行優(yōu)化，繼承自定義MyBaseAdapter，MyBaseAdapter繼承自BaseAdapter封裝一些常用的方法
 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) {
  //谷歌推出的優(yōu)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("電話和短信攔截");
  }else if(mode.equals("2")){
  holder.tv_mode.setText("電話攔截");
  }else if(mode.equals("3")){
  holder.tv_mode.setText("短信攔截");
  }
  final BlackNumberInfo info = lists.get(position);
  //監(jiān)聽刪除數(shù)據(jù)按鈕，刪除數(shù)據(jù)
  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, "刪除成功", Toast.LENGTH_SHORT).show();
   lists.remove(info);
   //更新ListView
   adapter.notifyDataSetChanged();
   }else{
   Toast.makeText(CallSafeActivity.this, "刪除失敗", Toast.LENGTH_SHORT).show();
   }
  }
  });
  return convertView;
  /*
  //谷歌推出的優(yōu)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("電話和短信攔截");
  }else if(mode.equals("2")){
  holder.tv_mode.setText("電話攔截");
  }else if(mode.equals("3")){
  holder.tv_mode.setText("短信攔截");
  }
  return convertView;
  */
  /*初步的優(yōu)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("電話和短信攔截");
  }else if(mode.equals("2")){
  tv_mode.setText("電話攔截");
  }else if(mode.equals("3")){
  tv_mode.setText("短信攔截");
  }
  return convertView;
  */
  /*傳統(tǒng)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("電話和短信攔截");
  }else if(mode.equals("2")){
  tv_mode.setText("電話攔截");
  }else if(mode.equals("3")){
  tv_mode.setText("短信攔截");
  }
  return view;
  */
 } 
 }
 static class ViewHolder{
 TextView tv_number;
 TextView tv_mode;
 ImageView iv_delete;
 }
}

上述就是小編為大家分享的如何在Android應(yīng)用中分批顯示 ListView數(shù)據(jù)了，如果剛好有類似的疑惑，不妨參照上述分析進行理解。如果想知道更多相關(guān)知識，歡迎關(guān)注億速云行業(yè)資訊頻道。

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