ListView的使用总结

展示列表的控件: ListView
MVC
mode 数据模型(List)
view 视图(ListView)
controller 控制器(把mode层的数据绑定到view上去)(Adapter适配器)

Adapter一般有三种BaseAdapter、ArrayAdapter、SimpleAdapter，其中最常用的是BaseAdapter。

本例中引用的PersonDao和Person类可参考这里：地址

1、BaseAdapter样例

package com.itheima28.sqlitedemo;

import java.util.List;

import com.itheima28.sqlitedemo.dao.PersonDao;
import com.itheima28.sqlitedemo.entities.Person;

import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends Activity {

    private List<Person> personList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ListView mListView = (ListView) findViewById(R.id.listview);

        PersonDao dao = new PersonDao(this);
        personList = dao.queryAll();

        // 把view层对象ListView和控制器BaseAdapter关联起来
        mListView.setAdapter(new MyAdapter());
    }


    class MyAdapter extends BaseAdapter {

        private static final String TAG = "MyAdapter";

        /**
         * 定义ListView的数据的长度
         */
        @Override
        public int getCount() {
            return personList.size();
        }

        @Override
        public Object getItem(int position) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return 0;
        }

        /**
         * 此方法返回的是ListView的列表中某一行的View对象
         * position 当前返回的view的索引位置
         * convertView 缓存对象
         * parent 就是ListView对象
         */
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {


            TextView tv = null;

            if(convertView != null) {       // 判断缓存对象是否为null,  不为null时已经缓存了对象
                Log.i(TAG, "getView: 复用缓存" + position);
                tv = (TextView) convertView;
            } else {    // 等于null, 说明第一次显示, 新创建
                Log.i(TAG, "getView: 新建" + position);
                tv = new TextView(MainActivity.this);
            }

            tv.setTextSize(25);

            Person person = personList.get(position); // 获得指定位置的数据, 进行对TextView的绑定

            tv.setText(person.toString());

            return tv;
        }

    }
}

2、ArrayAdapter样例

package com.itheima28.arrayadapterdemo;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ListView mListView = (ListView) findViewById(R.id.listview);
        String[] textArray = {"功能1","功能2","功能3","功能4","功能5","功能6","功能7","功能8"};

        /*
         * 定义数据适配器
         * android.R.layout.simple_list_item_1  Listview的子条目显示的布局的id
         * textArray 显示在ListView列表中的数据
         */
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, 
                android.R.layout.simple_list_item_1, 
                textArray);

        mListView.setAdapter(adapter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

3、SimpleAdapter样例

package com.itheima28.simpleadapterdemo;

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

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ListView mListView = (ListView) findViewById(R.id.listview);

        List<Map<String, Object>> data = new ArrayList<Map<String,Object>>();

        Map<String, Object> map = new HashMap<String, Object>();
        map.put("name", "张三1");
        map.put("icon", R.drawable.f007);
        data.add(map);

        map = new HashMap<String, Object>();
        map.put("name", "张三2");
        map.put("icon", R.drawable.f007);
        data.add(map);

        map = new HashMap<String, Object>();
        map.put("name", "张三3");
        map.put("icon", R.drawable.f007);
        data.add(map);

        map = new HashMap<String, Object>();
        map.put("name", "张三4");
        map.put("icon", R.drawable.f007);
        data.add(map);

        map = new HashMap<String, Object>();
        map.put("name", "张三5");
        map.put("icon", R.drawable.f007);
        data.add(map);

        SimpleAdapter adapter = new SimpleAdapter(
                this, // 上下文
                data, // listView绑定的数据
                R.layout.listview_item, // listview的子条目的布局的id
                new String[]{"name", "icon"},   // data数据中的map集合里的key
                new int[]{R.id.tv_name, R.id.iv_icon}); // resource 中的id

        mListView.setAdapter(adapter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}