Android列表组件ListView使用详解之动态加载或修改列表数据

/**
   * Notifies the attached observers that the underlying data has been changed
   * and any View reflecting the data set should refresh itself.
   */
  public void notifyDataSetChanged() {
    mDataSetObservable.notifyChanged();
  }

listViewDemoAdapter.notifyDataSetChanged();

package net.oschina.git.zhaikun.androiddeveloped.activitys;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;
import net.oschina.git.zhaikun.androiddeveloped.R;
import net.oschina.git.zhaikun.androiddeveloped.adapter.ListViewDemoAdapter;
import java.util.ArrayList;
import java.util.List;
/**
 * Created by zhaikun68 on 2018/3/5.
 * <p>
 * ListView演示Demo
 */
public class ListViewDemoActivity extends AppCompatActivity implements View.OnClickListener {
  private ListView testLv;//ListView组件
  private Button updateDataBtn;//动态加载数据组件
  private List<String> dataList = new ArrayList<>();//存储数据
  private ListViewDemoAdapter listViewDemoAdapter;//ListView的数据适配器
  @Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_listview_demo);
    initView();//初始化组件
    initData();//初始化数据
  }
  /**
   * 初始化组件
   */
  private void initView() {
    testLv = (ListView) findViewById(R.id.test_lv);
    updateDataBtn = (Button) findViewById(R.id.update_data_btn);
    updateDataBtn.setOnClickListener(this);
  }
  /**
   * 初始化数据
   */
  private void initData() {
    //初始化10项数据
    for (int i = 1; i <= 20; i++) {
      dataList.add("显示内容" + i);
    }
    //设置ListView的适配器
    listViewDemoAdapter = new ListViewDemoAdapter(this, dataList);
    testLv.setAdapter(listViewDemoAdapter);
    testLv.setSelection(4);
  }
  @Override
  public void onClick(View v) {
    switch (v.getId()) {
      case R.id.update_data_btn://动态加载列表数据
        dataList.add("动态加载的数据项");
        //通知ListView更改数据源
        if (listViewDemoAdapter != null) {
          listViewDemoAdapter.notifyDataSetChanged();
          testLv.setSelection(dataList.size() - 1);//设置显示列表的最后一项
        } else {
          listViewDemoAdapter = new ListViewDemoAdapter(this, dataList);
          testLv.setAdapter(listViewDemoAdapter);
          testLv.setSelection(dataList.size() - 1);
        }
        break;
    }
  }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
  <Button
    android:id="@+id/update_data_btn"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_margin="10dp"
    android:text="动态加载数据"/>
  <ListView
    android:id="@+id/test_lv"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_above="@id/update_data_btn"
    android:divider="@color/colorPrimaryDark"
    android:dividerHeight="3dp"
    android:listSelector="#ff0000"
    android:scrollbars="none"/>
</RelativeLayout>

package net.oschina.git.zhaikun.androiddeveloped.adapter;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import net.oschina.git.zhaikun.androiddeveloped.R;
import java.util.List;
/**
 * Created by zhaikun68 on 2018/3/5.
 * <p>
 * ListView演示Demo中的数据适配器
 */
public class ListViewDemoAdapter extends BaseAdapter {
  private Context context;//上下文对象
  private List<String> dataList;//ListView显示的数据
  /**
   * 构造器
   *
   * @param context 上下文对象
   * @param dataList 数据
   */
  public ListViewDemoAdapter(Context context, List<String> dataList) {
    this.context = context;
    this.dataList = dataList;
  }
  @Override
  public int getCount() {
    return dataList == null ? 0 : dataList.size();
  }
  @Override
  public Object getItem(int position) {
    return dataList.get(position);
  }
  @Override
  public long getItemId(int position) {
    return position;
  }
  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder viewHolder;
    //判断是否有缓存
    if (convertView == null) {
      convertView = LayoutInflater.from(context).inflate(R.layout.item_listview_demo, null);
      viewHolder = new ViewHolder(convertView);
      convertView.setTag(viewHolder);
    } else {
      //得到缓存的布局
      viewHolder = (ViewHolder) convertView.getTag();
    }
    //设置图片
    viewHolder.pictureImg.setImageResource(R.mipmap.ic_launcher);
    //设置内容
    viewHolder.contentTv.setText(dataList.get(position));
    return convertView;
  }
  /**
   * ViewHolder类
   */
  private final class ViewHolder {
    ImageView pictureImg;//图片
    TextView contentTv;//内容
    /**
     * 构造器
     *
     * @param view 视图组件（ListView的子项视图）
     */
    ViewHolder(View view) {
      pictureImg = (ImageView) view.findViewById(R.id.picture_img);
      contentTv = (TextView) view.findViewById(R.id.content_tv);
    }
  }
}

<?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="wrap_content"
       android:orientation="horizontal"
       android:padding="5dp">
  <ImageView
    android:id="@+id/picture_img"
    android:layout_width="30dp"
    android:layout_height="30dp"
    android:layout_marginRight="5dp"
    android:src="@mipmap/ic_launcher"/>
  <TextView
    android:id="@+id/content_tv"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_vertical"
    android:text="显示内容"/>
</LinearLayout>