Android BaseAdapter 图+文+代码 +ListView

建立一个item的java类，命名为,ItemBean.代码如下：

package com.example.bsaeadapter;

/**
 * Created by 联想 on 2016/6/29.
 */
public class ItemBean {
    public int ItemImageResId;
    public String Itemtitle;
    public String ItemContent;

    public ItemBean(int itemImageResId, String itemtitle, String itemContent) {
        ItemImageResId = itemImageResId;
        Itemtitle = itemtitle;
        ItemContent = itemContent;
    }
}

这个用于获取数据。

新建一个名为item.xml的子布局文件，代码如下：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <ImageView
        android:id="@+id/lv_image"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:src="@mipmap/ic_launcher"/>
        <TextView
            android:id="@+id/tv_title"
            android:layout_width="match_parent"
            android:layout_height="30dp"
            android:layout_toEndOf="@+id/lv_image"
            android:text="Title"
            android:gravity="center"
            android:textSize="25sp"/>
    <TextView
        android:id="@+id/tv_content"
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:layout_toEndOf="@+id/lv_image"
        android:layout_below="@+id/tv_title"
        android:text="Content"
        android:gravity="center_vertical"
        android:textSize="20sp"/>


</RelativeLayout>

建立适配器java类命名为MyAdapter，代码如下：

package com.example.bsaeadapter;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.List;

import static com.example.bsaeadapter.R.id.tv_title;

/**
 * Created by 联想 on 2016/6/29.
 */
public class MyAdapter extends BaseAdapter{
    private List<ItemBean> mList;
    private LayoutInflater minflater;

    public MyAdapter(Context context, List<ItemBean> list) {
        mList = list;
        minflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return mList.size();
    }

    @Override
    public Object getItem(int i) {
        return mList.get(i);
    }

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

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        //没有利用缓存机制的适配器，没有任何优化处理
   /*    View v = minflater.inflate(R.layout.item,null);
         ImageView imageView = (ImageView) v.findViewById(R.id.lv_image);
         TextView title = (TextView) v.findViewById(tv_title);

        ItemBean bean = mList.get(i);

        TextView content = (TextView) v.findViewById(R.id.tv_content);
        imageView.setImageResource(bean.ItemImageResId);
        title.setText(bean.Itemtitle);
        content.setText(bean.ItemContent);
         return v;
        */
        //，没有优化处理
        /*
        //普通的优化的适配器
        if(view == null)
        {
            //利用的Listview的缓存机制
            view = minflater.inflate(R.layout.item,null);

            return view;
        }
        ImageView imageView = (ImageView) view.findViewById(R.id.lv_image);
        TextView title = (TextView) view.findViewById(tv_title);

        ItemBean bean = mList.get(i);

        TextView content = (TextView) view.findViewById(R.id.tv_content);
        imageView.setImageResource(bean.ItemImageResId);
        title.setText(bean.Itemtitle);
        content.setText(bean.ItemContent);
        return view;
        //普通的listview适配
        */

        //最好的适配优化方案，避免耗时操作，内存优化，和少使用findviewbyid进行优化
        ViewHolder viewHolder;
        if (view == null)
        {
            viewHolder = new ViewHolder();
            view = minflater.inflate(R.layout.item,null);
            viewHolder.imageView = (ImageView) view.findViewById(R.id.lv_image);
            viewHolder.title = (TextView) view.findViewById(tv_title);
            viewHolder.content = (TextView) view.findViewById(R.id.tv_content);
            view.setTag(viewHolder);
        }else {
           viewHolder = (ViewHolder) view.getTag();
        }
        ItemBean bean = mList.get(i);

        TextView content = (TextView) view.findViewById(R.id.tv_content);
        viewHolder.imageView.setImageResource(bean.ItemImageResId);
        viewHolder.title.setText(bean.Itemtitle);
        viewHolder.content.setText(bean.ItemContent);
        return view;



    }
    class ViewHolder {

        public ImageView imageView;
        public TextView title;
        public TextView content;
    }
}

接下来在主布局中使用。。MainActivity代码如下：

package com.example.bsaeadapter;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ListView;

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

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        List<ItemBean> itemBeanList = new ArrayList<>();
        for (int i = 0;i<20;i++)
        {
            itemBeanList.add(new ItemBean(
                    R.mipmap.ic_launcher,
                    "我是标题"+i,
                    "我是内容"+i
            ));
        }
        ListView listView = (ListView) findViewById(R.id.iv_main);
        listView.setAdapter(new MyAdapter(this,itemBeanList));
    }
}

对应的主布局文件activity_main.xml代码如下：

<?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: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.example.bsaeadapter.MainActivity">

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

。。

接下来好好享受，学习吧。。。。唯有努力和汗水不会让你失望，加油吧，骚年。