笔记20 使用ArrayAdapter、ArrayAdapter为ListView添加数据

目标

1、理解ListView的基础使用

2、学会熟练运用两种适配器(ArrayAdapter、SimpleAdapter)
3、学会熟练运用两种监听器(OnScrollListener,OnItemClickListener)

4、学会熟练运用适配器数据的刷新(notifyDataChanged)

MainActivity

package com.example.adapter;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class MainActivity extends AppCompatActivity implements AdapterView.OnItemClickListener,
        AbsListView.OnScrollListener {

    private static final String TAG = "MainActivity";
    private ListView mListView;
    private ArrayAdapter mArrayAdapter;
    private SimpleAdapter mSimpleAdapter;
    private List> dataList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 匹配布局文件中的ListView控件
        setContentView(R.layout.main);
        mListView = (ListView) findViewById(R.id.listview);

        //1、新建一个数据适配器
        //ArrayAdapter(上下文,当前listView加载的每一个列表项对应的布局文件,数据源)
        /**
         * SimpleAdapter(Context context, List> data, int resource,
         * String[] from, int[] to)
         * Context context: 上下文
         * List> data :数据源 一个map所组成的Listj集合
         *                                每一个map都会对应listview里的一行
         *                                每一个map(键-值对)中的键必须包含所有from中指定的键
         * int resource   :列表项的布局文件
         * String[] from  :map中的键名
         * int[] to       :绑定数据视图中的ID,与from成对应关系
         */

        //2、适配器加载数据源
        String[] arr_data = {"ban1", "ban2", "ban3"};
        mArrayAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1,
                arr_data);
        dataList = new ArrayList>();

        mSimpleAdapter = new SimpleAdapter(this, getData(), R.layout.item,
                new String[]{"pic", "text"}, new int[]{R.id.pic, R.id.text});
        //3、视图(ListView)加载适配器
        //mListView.setAdapter(mArrayAdapter);
        mListView.setAdapter(mSimpleAdapter);

        mListView.setOnItemClickListener(this);
        mListView.setOnScrollListener(this);
    }


    private List> getData() {
        for (int i = 0; i < 20; i++) {
            Map map = new HashMap();
            map.put("pic", R.mipmap.ic_launcher);
            map.put("text", "ban" + i);
            dataList.add(map);
        }
        return dataList;
    }

    @Override
    public void onScrollStateChanged(AbsListView absListView, int scrollState) {
        switch (scrollState) {
            case SCROLL_STATE_FLING:
                Log.e(TAG, "onScrollStateChanged: SCROLL_STATE_FLING");
                Toast.makeText(MainActivity.this, "用力滑一下",Toast.LENGTH_SHORT).show();
                Map map = new HashMap();
                map.put("pic",R.mipmap.ic_launcher);
                map.put("text","增加项");
                dataList.add(map);
                mSimpleAdapter.notifyDataSetChanged();
                break;
            case SCROLL_STATE_IDLE:
                Log.e(TAG, "onScrollStateChanged: SCROLL_STATE_IDLE");
                break;
            case SCROLL_STATE_TOUCH_SCROLL:
                Log.e(TAG, "onScrollStateChanged: SCROLL_STATE_TOUCH_SCROLL");
                break;
        }
    }

    @Override
    public void onScroll(AbsListView absListView, int i, int i1, int i2) {

    }

    @Override
    public void onItemClick(AdapterView adapterView, View view, int i, long l) {
        // 获取点击ListView item中的内容信息
        String text = mListView.getItemAtPosition(i) + "";
        // 弹出Toast信息显示点击位置和内容
        Toast.makeText(MainActivity.this,
                "position=" + i + " content=" + text, Toast.LENGTH_SHORT).show();
    }
}

main.xml

item.xml

运行效果：