android 71 ArrayAdapter和SimpleAdapter

Activity和item：

Activity：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <ListView
        android:id="@+id/lv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />

</RelativeLayout>



item:
<?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" >
    
    <ImageView 
        android:id="@+id/iv_photo"
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:src="@drawable/photo3"
        />
    <TextView 
        android:id="@+id/tv_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="名字"
        android:textSize="22sp"
        android:layout_gravity="center_vertical"
        />

</LinearLayout>

java:

package com.itheima.arraysimple;

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

import android.os.Bundle;
import android.app.Activity;
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);
        
        String[] objects = new String[]{
                "小志",
                "小志的儿子",
                "萌萌"
        };
        
        ListView lv = (ListView) findViewById(R.id.lv);
        
        //ArrayAdapter只能够处理一种数据类型String，做了高度的封装。
        lv.setAdapter(new ArrayAdapter<String>(this, R.layout.item_listview, R.id.tv_name, objects));
        
        //集合中每个元素都包含ListView条目需要的所有数据,该案例中每个条目需要一个字符串和一个整型,所以使用一个map来封装这两种数据
        List<Map<String, Object>> data = new ArrayList<Map<String,Object>>();
        
        Map<String, Object> map1 = new HashMap<String, Object>();
        map1.put("photo", R.drawable.photo1);
        map1.put("name", "小志的儿子");
        data.add(map1);
        
        Map<String, Object> map2 = new HashMap<String, Object>();
        map2.put("photo", R.drawable.photo2);
        map2.put("name", "小志");
        data.add(map2);
        
        Map<String, Object> map3 = new HashMap<String, Object>();
        map3.put("photo", R.drawable.photo3);
        map3.put("name", "赵帅哥");
        data.add(map3);
        
        //SimpleAdapter，item_listview是item，
        //new String[]{"photo", "name"}, new int[]{R.id.iv_photo, R.id.tv_name}指定photo放入R.id.iv_photo组件，name放入R.id.tv_name组件
        lv.setAdapter(new SimpleAdapter(this, data, R.layout.item_listview, 
                new String[]{"photo", "name"}, new int[]{R.id.iv_photo, R.id.tv_name}));
    }


}