java - 关于鸿洋博客的打造万能Adapter的实践问题？

Question

这是鸿洋的一篇文章Android 快速开发系列 打造万能的ListView GridView 适配器

里面用到的item是只有一个TextView的，但是我想把item的布局弄复杂一点，因为我是新手，所以看不太懂博客最后的那段代码

// 设置适配器  
        mListView.setAdapter(mAdapter = new CommonAdapter<Bean>(  
                getApplicationContext(), mDatas, R.layout.item_list)  
        {  
            @Override  
            public void convert(ViewHolder helper, Bean item)  
            {  
                helper.setText(R.id.tv_title, item.getTitle());  
                helper.setText(R.id.tv_describe, item.getDesc());  
                helper.setText(R.id.tv_phone, item.getPhone());  
                helper.setText(R.id.tv_time, item.getTime());  
                  
//              helper.getView(R.id.tv_title).setOnClickListener(l)  
            }  
  
        });  

他博客里面并没有那几个getTitle，getPhone方法，不知道他是怎么改的，还有他那个item的数据，在他之前给的例子里用的是一维数组，没有用到key、value这种形式，所以我想给我的item布局稍微修改复杂一点也不知道怎么改了，希望大家能帮帮忙，谢谢，下面贴出我本身程序的代码：
activity_main.xml

    <?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"
    android:orientation="vertical"
    tools:context="com.hanksenye.newgridviewlearn.MainActivity">

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

item.xml

<?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="match_parent"
    android:orientation="vertical">

    <TextView
        android:id="@+id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="18sp"/>

    <TextView
        android:id="@+id/info"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="12sp"/>

</LinearLayout>

ViewHolder.java

package com.hanksenye.newgridviewlearn;

import android.content.Context;
import android.graphics.Bitmap;
import android.util.Log;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

public class ViewHolder
{
    private final SparseArray<View> mViews;
    private int mPosition;
    private View mConvertView;

    private ViewHolder(Context context, ViewGroup parent, int layoutId,
                       int position)
    {
        this.mPosition = position;
        this.mViews = new SparseArray<View>();
        mConvertView = LayoutInflater.from(context).inflate(layoutId, parent,
                false);
        // setTag
        mConvertView.setTag(this);
    }

    /**
     * 拿到一个ViewHolder对象
     *
     * @param context
     * @param convertView
     * @param parent
     * @param layoutId
     * @param position
     * @return
     */
    public static ViewHolder get(Context context, View convertView,
                                 ViewGroup parent, int layoutId, int position)
    {
        if (convertView == null)
        {
            return new ViewHolder(context, parent, layoutId, position);
        }
        return (ViewHolder) convertView.getTag();
    }

    public View getConvertView()
    {
        return mConvertView;
    }

    /**
     * 通过控件的Id获取对于的控件，如果没有则加入views
     *
     * @param viewId
     * @return
     */
    public <T extends View> T getView(int viewId)
    {
        View view = mViews.get(viewId);
        if (view == null)
        {
            view = mConvertView.findViewById(viewId);
            mViews.put(viewId, view);
        }
        return (T) view;
    }

    /**
     * 为TextView设置字符串
     *
     * @param viewId
     * @param text
     * @return
     */
    public ViewHolder setText(int viewId, String text)
    {
        TextView view = getView(viewId);
        view.setText(text);
        return this;
    }

    /**
     * 为ImageView设置图片
     *
     * @param viewId
     * @param drawableId
     * @return
     */
    public ViewHolder setImageResource(int viewId, int drawableId)
    {
        ImageView view = getView(viewId);
        view.setImageResource(drawableId);

        return this;
    }

    /**
     * 为ImageView设置图片
     *
     * @param viewId
     * @param bm
     * @return
     */
    public ViewHolder setImageBitmap(int viewId, Bitmap bm)
    {
        ImageView view = getView(viewId);
        view.setImageBitmap(bm);
        return this;
    }
//
//    /**
//     * 为ImageView设置图片
//     *
//     * @param viewId
//     * @param drawableId
//     * @return
//     */
//    public ViewHolder setImageByUrl(int viewId, String url)
//    {
//        ImageLoader.getInstance(3, Type.LIFO).loadImage(url,
//                (ImageView) getView(viewId));
//        return this;
//    }

    public int getPosition()
    {
        return mPosition;
    }

}

CommonAdapter.java

package com.hanksenye.newgridviewlearn;

import java.util.List;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

public abstract class CommonAdapter<T> extends BaseAdapter
{
    protected LayoutInflater mInflater;
    protected Context mContext;
    protected List<T> mDatas;
    protected final int mItemLayoutId;

    public CommonAdapter(Context context, List<T> mDatas, int itemLayoutId)
    {
        this.mContext = context;
        this.mInflater = LayoutInflater.from(mContext);
        this.mDatas = mDatas;
        this.mItemLayoutId = itemLayoutId;
    }

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

    @Override
    public T getItem(int position)
    {
        return mDatas.get(position);
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent)
    {
        final ViewHolder viewHolder = getViewHolder(position, convertView,
                parent);
        convert(viewHolder, getItem(position));
        return viewHolder.getConvertView();

    }

    public abstract void convert(ViewHolder helper, T item);

    private ViewHolder getViewHolder(int position, View convertView,
                                     ViewGroup parent)
    {
        return ViewHolder.get(mContext, convertView, parent, mItemLayoutId,
                position);
    }

}

MainActivity.java

package com.hanksenye.newgridviewlearn;

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

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

public class MainActivity extends AppCompatActivity {

    private ListView listView;
    private List<String> title = new ArrayList<String>(Arrays.asList("菜名0", "菜名1", "菜名2", "菜名3", "菜名4", "菜名5", "菜名6", "菜名7", "菜名8", "菜名9"));
    private List<String> info = new ArrayList<String>(Arrays.asList("￥：28", "￥：28", "￥：28", "￥：28", "￥：28", "￥：28", "￥：28", "￥：28", "￥：28", "￥：28"));

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        listView = (ListView) findViewById(R.id.listview);
        listView.setAdapter(new CommonAdapter<String>(getApplicationContext(),title,R.layout.item) {
            @Override
            public void convert(ViewHolder helper, String item) {
                helper.setText(R.id.title, item);
                helper.setText(R.id.info, item);
            }
        });
    }

}

就是上面的MainActivity那2个一维数组，我的想法是把它们弄成key、value的形式的，可是adapter是<T>形式，我用key、value形式我用的是<Map<K,V>>，不知道描述的有没有错误，希望有大神解答，现在程序是可以运行的，可是就是item只有一个数据源，希望能给我举多几个例子让我理解一下，谢谢大家

Answer 1

Yes, do you know why this T is used? In practical applications, many times your data source is an entity.

List<Goods> mShops;
class Goods {
    public String name;
    public double price;
}

Think again.

Answer 2

Then do you know why this T is used