Android万能适配器Adapter

欢迎大家补充

我们经常要书写Adapter,但是Adapter里面的重复代码很多,所以我们可以复用一下 ,只要是ViewHolder的部分和Adapter的部分##

常用的继承BaseAdapter的Adapter的代码如下

package com.example.euler_kalvinhe.myadapter.adapter;

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

import com.example.euler_kalvinhe.myadapter.R;
import com.example.euler_kalvinhe.myadapter.bean.Bean;

import java.util.List;

/**
 * Created by Euler-KalvinHe on 2015/8/20.
 */
public class MyAdapter  extends BaseAdapter{
    private LayoutInflater inflater;
    private List listData;
    public MyAdapter(Context context,List list) {
        inflater = LayoutInflater.from(context);
        this.listData = list;
    }

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

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

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

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        ViewHolder holder;
        if (view == null){
            view = inflater.inflate(R.layout.item,viewGroup,false);
            holder = new ViewHolder();
            holder.title = (TextView) view.findViewById(R.id.title);
            holder.desc = (TextView) view.findViewById(R.id.desc);
            holder.time = (TextView) view.findViewById(R.id.time);
            holder.phone = (TextView) view.findViewById(R.id.phone);
            view.setTag(holder);
        }
        else {
            holder = (ViewHolder) view.getTag();
        }
        Bean bean = listData.get(i);
        holder.title.setText(bean.getTitle());
        holder.desc.setText(bean.getDesc());
        holder.time.setText(bean.getTime());
        holder.phone.setText(bean.getPhone());
        return view;
    }
    private class ViewHolder{
        TextView title;
        TextView desc;
        TextView time;
        TextView phone;
    }
}

对ViewHolder进行进行抽取,主要是初始化布局,判断ConvertView是否已经建立 ,注意重用Viewholder的时候position的设置,代码如下##

package com.example.euler_kalvinhe.myadapter.utility;
import android.content.Context;
import android.graphics.Bitmap;
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 mViews;
    private int mPosition;
    private View mConvertView;

    private ViewHolder(Context context, ViewGroup parent, int layoutId,
                       int position)
    {
        this.mPosition = position;
        this.mViews = new SparseArray();
        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 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 drawableId
     * @return
     */
    public ViewHolder setImageBitmap(int viewId, Bitmap bm)
    {
        ImageView view = getView(viewId);
        view.setImageBitmap(bm);
        return this;
    }




    public int getPosition()
    {
        return mPosition;
    }

}

Adapter类的抽取,主要是利用泛型实现了BaseAdapter的抽象方法

package  com.example.euler_kalvinhe.myadapter.utility;

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

import java.util.List;

public abstract class CommenAdapter extends BaseAdapter
{
    protected LayoutInflater mInflater;
    protected Context mContext;
    protected List mDatas;
    protected final int mItemLayoutId;

    public CommenAdapter(Context context, List 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);
    }

}

activity的代码.匿名实现了Adapter

package com.example.euler_kalvinhe.myadapter;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.TextView;

import com.example.euler_kalvinhe.myadapter.bean.Bean;
import com.example.euler_kalvinhe.myadapter.utility.CommenAdapter;
import com.example.euler_kalvinhe.myadapter.utility.ViewHolder;

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


public class MainActivity extends Activity {
    private ListView listView;
    private List listData = new ArrayList();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initViews();
        initData();
        listView.setAdapter(new CommenAdapter(MainActivity.this,listData,R.layout.item) {
            @Override
            public void convert(ViewHolder holder, final Bean bean) {
                ((TextView)holder.getView(R.id.title)).setText(bean.getTitle());
                ((TextView)holder.getView(R.id.desc)).setText(bean.getDesc());
                ((TextView)holder.getView(R.id.time)).setText(bean.getTime());
                ((TextView)holder.getView(R.id.phone)).setText(bean.getPhone());
                final CheckBox checkBox = holder.getView(R.id.checkbox);
                checkBox.setChecked(bean.isChecked());
                checkBox.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        bean.setChecked(checkBox.isChecked());
                    }
                });
            }
        });
    }

    private void initData() {
        Bean bean = new Bean("android新技能","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean);
        Bean bean1 = new Bean("android新技能1","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean1);
        Bean bean2 = new Bean("android新技能2","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean2);
        Bean bean3 = new Bean("android新技能3","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean3);
        Bean bean4 = new Bean("android新技能4","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean4);
        Bean bean5 = new Bean("android新技能5","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean5);
        Bean bean6 = new Bean("android新技能6","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean6);
        Bean bean7 = new Bean("android新技能7","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean7);
        Bean bean8 = new Bean("android新技能8","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean8);
        Bean bean9 = new Bean("android新技能9","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean9);
        Bean bean10 = new Bean("android新技能10","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean10);
        Bean bean11= new Bean("android新技能11","打造万能的adapter和Viewholder","201304","10086");
        listData.add(bean11);

    }

    private void initViews() {

        listView = (ListView) findViewById(R.id.listView);
    }
}

Bean是数据类,初始化了变量

package com.example.euler_kalvinhe.myadapter.bean;

/**
 * Created by Euler-KalvinHe on 2015/8/20.
 */
public class Bean {
    private String title;
    private String desc;
    private String phone;
    private String time;
    private boolean isChecked;

    public Bean(String title, String desc, String time, String phone) {
        this.desc = desc;
        this.phone = phone;
        this.time = time;
        this.title = title;
    }

    public boolean isChecked() {
        return isChecked;
    }

    public void setChecked(boolean isChecked) {
        this.isChecked = isChecked;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getDesc() {
        return desc;
    }

    public void setDesc(String desc) {
        this.desc = desc;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getTime() {
        return time;
    }

    public void setTime(String time) {
        this.time = time;
    }
}

布局类主要是主布局.包含ListView和item的布局

效果图

!!!要注意的两个问题

1.第一个item中加入了CheckBox,CheckBox会抢焦点,使得勾选自己有效,然而点击整个item无效,这个问题,可以通过在item的根布局RelativeLayout里面加一句 android:descendantFocusability=“blocksDescendants”##

2.第二个问题就是由于ViewHolder的复用导致,勾选前面的CheckBox,后面的自动勾选,解决办法是在Bean加入一个表示CheckBox是否勾选的布尔变量isChecked,具体如下

Bean里面

private boolean isChecked;
ublic boolean isChecked() {
        return isChecked;
    }

    public void setChecked(boolean isChecked) {
        this.isChecked = isChecked;
    }

activity里面

final CheckBox checkBox = holder.getView(R.id.checkbox);
                checkBox.setChecked(bean.isChecked());
                checkBox.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        bean.setChecked(checkBox.isChecked());
                    }
                });