目標

1、理解ListView的基礎使用

4、學會熟練運用介面卡資料的重新整理(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<String> mArrayAdapter;
    private SimpleAdapter mSimpleAdapter;
    private List<Map<String, Object>> dataList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 匹配佈局檔案中的ListView控制元件
        setContentView(R.layout.main);
        mListView = (ListView) findViewById(R.id.listview);

        //1、新建一個數據介面卡
        //ArrayAdapter(上下文,當前listView載入的每一個列表項對應的佈局檔案,資料來源)
        /**
         * SimpleAdapter(Context context, List<? extends Map<String, ?>> data, int resource,
         * String[] from, int[] to)
         * Context context: 上下文
         * List<? extends Map<String, ?>> data :資料來源 一個map所組成的Listj集合
         *                                每一個map都會對應listview裡的一行
         *                                每一個map(鍵-值對)中的鍵必須包含所有from中指定的鍵
         * int resource   :列表項的佈局檔案
         * String[] from  :map中的鍵名
         * int[] to       :繫結資料檢視中的ID,與from成對應關係
         */

        //2、介面卡載入資料來源
        String[] arr_data = {"ban1", "ban2", "ban3"};
        mArrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,
                arr_data);
        dataList = new ArrayList<Map<String, Object>>();

        mSimpleAdapter = new SimpleAdapter(this, getData(), R.layout.item,
                new String[]{"pic", "text"}, new int[]{R.id.pic, R.id.text});
        //3、檢視(ListView)載入介面卡
        //mListView.setAdapter(mArrayAdapter);
        mListView.setAdapter(mSimpleAdapter);

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


    private List<Map<String, Object>> getData() {
        for (int i = 0; i < 20; i++) {
            Map<String, Object> map = new HashMap<String, Object>();
            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<String,Object> map = new HashMap<String,Object>();
                map.put("pic",R.mipmap.ic_launcher);
                map.put("text","增加項");
                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) {
        // 獲取點選ListView item中的內容資訊
        String text = mListView.getItemAtPosition(i) + "";
        // 彈出Toast資訊顯示點選位置和內容
        Toast.makeText(MainActivity.this,
                "position=" + i + " content=" + text, Toast.LENGTH_SHORT).show();
    }
}
 

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.adapter.MainActivity">

    <ListView
        android:id="@+id/listview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        />
</RelativeLayout>
 

item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="horizontal"
              android:layout_width="match_parent"
              android:layout_height="50dp"
              android:background="@color/colorAccent"
              android:gravity="center"
    >

    <ImageView
        android:id="@+id/pic"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="15dp"
        android:src="@mipmap/ic_launcher"
        />
    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="demo"
        android:textSize="20dp"
        />
</LinearLayout>
 

執行效果：