Android——BaseAdapter相关

<?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>

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;
}
}
}