Android——BaseAdapter相关

layout文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.hanqi.testapp2.TestActivity8">

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/lv_3"></ListView>
</LinearLayout>

java类：

package com.hanqi.testapp2;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class TestActivity8 extends AppCompatActivity {

    ListView lv_3;
    List<MyClass> lm;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_test8);

        lv_3 = (ListView)findViewById(R.id.lv_3);

        //数据集合
        lm = new ArrayList<>();
        MyClass myClass = new MyClass(R.drawable.f1,"美食1","美食1的介绍");
        lm.add(myClass);
        lm.add(new MyClass(R.drawable.f2,"美食2","美食2的介绍"));
        lm.add(new MyClass(R.drawable.f3,"美食3","美食3的介绍"));
        lm.add(new MyClass(R.drawable.f4,"美食4","美食4的介绍"));
        lm.add(new MyClass(R.drawable.f5,"美食5","美食5的介绍"));
        lm.add(new MyClass(R.drawable.f6,"美食6","美食6的介绍"));
        lm.add(new MyClass(R.drawable.f7,"美食7","美食7的介绍"));
        lm.add(new MyClass(R.drawable.f8,"美食8","美食8的介绍"));
        lm.add(new MyClass(R.drawable.f9,"美食9","美食9的介绍"));

        MyBaseAdapter myBaseAdapter = new MyBaseAdapter();
        {
            lv_3.setAdapter(myBaseAdapter);
        }
    }

    //装载数据的类 实体类 POJO类
    //只包含属性和属性的getter和setter方法
    class MyClass
    {
        //img
        private int img;
        //name
        private String name;
        //content
        private String content;

        public int getImg() {
            return img;
        }

        public void setImg(int img) {
            this.img = img;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public String getContent() {
            return content;
        }

        public void setContent(String content) {
            this.content = content;
        }
        //默认构造方法
        public MyClass()
        {

        }
        //直接初始化属性的构造方法
        public MyClass(int img,String name,String content)
        {
            this.img = img;
            this.name = name;
            this.content = content;
        }
    }

    //内部类继承抽象类BaseAdapter实现4个方法
    class MyBaseAdapter extends BaseAdapter
    {
        @Override
        public int getCount() {
            return lm.size();
        }

        @Override
        public Object getItem(int position) {
            return lm.get(position);
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }

        //返回适配完成的视图
        //convertView 可以复用的视图
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {

            //适配一条数据和View
            //1.得到数据
            MyClass myClass = lm.get(position);

            if (convertView ==null)
            {
                Log.e("TAG","适配器getView = "+position);
                //2.得到 View
                //加载layout文件
                convertView = View.inflate(TestActivity8.this, R.layout.simple_adapter, null);
            }
            //3.把数据放到View里
            ImageView imageView = (ImageView)convertView.findViewById(R.id.iv_2);
            imageView.setImageResource(myClass.getImg());

            TextView textView = (TextView)convertView.findViewById(R.id.tv_7);
            textView.setText(myClass.getName());

            TextView textView1 = (TextView)convertView.findViewById(R.id.tv_8);
            textView1.setText(myClass.getContent());
            return convertView;
        }
    }
}

效果图为：