201.m1-优化抽取Adapter二之抽取ViewHolder

注意到刚才的几个ViewHolder很多都是类似的，因此ViewHolder也可以抽取出来单独抽到BaseHolder，继承BaseHolder即可

BaseHolder.java

package com.ldw.market.holder; import android.view.View; import com.ldw.market.utils.BitmapHelper; import com.lidroid.xutils.BitmapUtils; /* * ViewHolder共性的抽取 */ public abstract class BaseHolder<Data> { private View contentView; private Data data; protected BitmapUtils bitmapUtils; //构造方法 public BaseHolder(){ bitmapUtils = BitmapHelper.getBitmapUtils(); contentView=initView(); contentView.setTag(this); } /** 创建界面*/ public abstract View initView(); public View getContentView() { return contentView; } public void setData(Data data){ this.data=data; refreshView(data); } /** 根据数据刷新界面*/ public abstract void refreshView(Data data); }

抽取以后的HomeFragment.java

package com.ldw.market.fragment; import java.util.List; import android.os.Bundle; import android.text.format.Formatter; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.ListView; import android.widget.RatingBar; import android.widget.TextView; import com.ldw.market.R; import com.ldw.market.Adapter.DefaultAdapter; import com.ldw.market.domain.AppInfo; import com.ldw.market.holder.BaseHolder; import com.ldw.market.http.HttpHelper; import com.ldw.market.protocol.HomeProtocal; import com.ldw.market.utils.UiUtils; import com.ldw.market.utils.BitmapHelper; import com.ldw.market.view.BaseListView; import com.lidroid.xutils.BitmapUtils; import com.lidroid.xutils.bitmap.PauseOnScrollListener; /* * Home页面，主体的加载的几个页面和服务器请求数据都是在BaseFragment中去实现 */ public class HomeFragment extends BaseFragment { private List<AppInfo> appInfos; // 当Fragment挂载的activity创建的时候调用 @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); show(); } public View createSuccessView() { //使用自定义的ListView,ListView初始化的时候会初始化几个方法 BaseListView listView = new BaseListView(UiUtils.getContext()); listView.setAdapter(new HomeAdapter(appInfos)); // 第二个参数 慢慢滑动的时候是否加载图片 false 加载 true 不加载 // 第三个参数 飞速滑动的时候是否加载图片 true 不加载 listView.setOnScrollListener(new PauseOnScrollListener(bitmapUtils, false, true)); bitmapUtils.configDefaultLoadingImage(R.drawable.ic_default); // 设置如果图片加载中显示的图片 bitmapUtils.configDefaultLoadFailedImage(R.drawable.ic_default);// 加载失败显示的图片 return listView; } private class HomeAdapter extends DefaultAdapter<AppInfo>{ //构造函数，初始化数据 public HomeAdapter(List<AppInfo> appInfos) { super(appInfos); // TODO Auto-generated constructor stub } @Override protected BaseHolder<AppInfo> getHolder() { // TODO Auto-generated method stub return new ViewHolder(); } } static class ViewHolder extends BaseHolder<AppInfo>{ ImageView item_icon; TextView item_title,item_size,item_bottom; RatingBar item_rating; //更新界面 @Override public void refreshView(AppInfo data){ this.item_title.setText(data.getName());// 设置应用程序的名字 String size = Formatter.formatFileSize(UiUtils.getContext(), data.getSize()); this.item_size.setText(size); this.item_bottom.setText(data.getDes()); float stars = data.getStars(); this.item_rating.setRating(stars); // 设置ratingBar的值 String iconUrl = data.getIconUrl(); //这个地址不全，需要加上apache地址"iconUrl": "app/com.youyuan.yyhl/icon.jpg", //http://127.0.0.1:8090/image?name=app/com.youyuan.yyhl/icon.jpg //第一个参数是显示图片的控件，第二个参数是显示图片的url bitmapUtils.display(this.item_icon, HttpHelper.URL+"image?name="+iconUrl); // 显示图片的控件 //bitmapUtils.display(holder.item_icon, HttpHelper.URL+"image?name="+iconUrl); } @Override public View initView() { View contentView = View.inflate(UiUtils.getContext(), R.layout.item_app, null); this.item_icon = (ImageView) contentView.findViewById(R.id.item_icon); this.item_title = (TextView) contentView.findViewById(R.id.item_title); this.item_size = (TextView) contentView.findViewById(R.id.item_size); this.item_bottom = (TextView) contentView.findViewById(R.id.item_bottom); this.item_rating = (RatingBar) contentView.findViewById(R.id.item_rating); return contentView; } } @Override public LoadResult load() { HomeProtocal protocol = new HomeProtocal(); appInfos = protocol.load(0); return checkData(appInfos); } } 抽取以后的SubjectFragment.java

package com.ldw.market.fragment; import java.util.List; import com.ldw.market.R; import com.ldw.market.Adapter.DefaultAdapter; import com.ldw.market.domain.SubjectInfo; import com.ldw.market.fragment.BaseFragment.LoadResult; import com.ldw.market.holder.BaseHolder; import com.ldw.market.http.HttpHelper; import com.ldw.market.protocol.SubjectProtocol; import com.ldw.market.utils.BitmapHelper; import com.ldw.market.utils.UiUtils; import com.lidroid.xutils.BitmapUtils; import android.os.Bundle; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.ListView; import android.widget.TextView; public class SubjectFragment extends BaseFragment { private List<SubjectInfo> datas; @Override public View createSuccessView() { ListView listView=new ListView(UiUtils.getContext()); listView.setAdapter(new SubjectAdapter(datas)); return listView; } private class SubjectAdapter extends DefaultAdapter<SubjectInfo>{ //构造函数，初始化数据 public SubjectAdapter(List<SubjectInfo> datas) { super(datas); // TODO Auto-generated constructor stub } @Override protected BaseHolder<SubjectInfo> getHolder() { return new ViewHolder(); } } class ViewHolder extends BaseHolder<SubjectInfo>{ ImageView item_icon; TextView item_txt; //更新界面 @Override public void refreshView(SubjectInfo data){ this.item_txt.setText(data.getDes()); bitmapUtils.display(this.item_icon, HttpHelper.URL+"image?name="+data.getUrl()); } @Override public View initView() { View contentView=View.inflate(UiUtils.getContext(), R.layout.item_subject, null); this.item_icon=(ImageView) contentView.findViewById(R.id.item_icon); this.item_txt=(TextView) contentView.findViewById(R.id.item_txt); return contentView; } } @Override protected LoadResult load() { SubjectProtocol protocol=new SubjectProtocol(); datas = protocol.load(0); return checkData(datas); } } DefaultAdapter.java共性的Adapter

package com.ldw.market.Adapter; import java.util.List; import com.ldw.market.domain.AppInfo; import com.ldw.market.holder.BaseHolder; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; /* * BaseAdapter的共性方法的封装,使用泛型封装 */ public abstract class DefaultAdapter<Data> extends BaseAdapter{ protected List<Data> datas; //get方法 public List<Data> getDatas() { return datas; } //set方法 public void setDatas(List<Data> datas) { this.datas = datas; } //构造函数，初始化数据 public DefaultAdapter(List<Data> datas) { this.datas = datas; } @Override public int getCount() { // TODO Auto-generated method stub return datas.size(); } @Override public Object getItem(int position) { // TODO Auto-generated method stub return datas.get(position); } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { //BaseHolder使用泛型以支持多种数据类型的Holder BaseHolder<Data> holder; if(convertView == null){ //每一个栏目的holder不一样 holder = getHolder(); }else{ holder = (BaseHolder) convertView.getTag(); } Data data = datas.get(position); holder.setData(data); return holder.getContentView(); } protected abstract BaseHolder<Data> getHolder(); } BaseHolder.java共性的ViewHolder，需要注意的是每一个项目的ViewHolder是不一样的，因此让子类去返回Holder，使用抽象的方法getHolder来获取子类的ViewHolder(); package com.ldw.market.Adapter; import java.util.List; import com.ldw.market.domain.AppInfo; import com.ldw.market.holder.BaseHolder; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; /* * BaseAdapter的共性方法的封装,使用泛型封装 */ public abstract class DefaultAdapter<Data> extends BaseAdapter{ protected List<Data> datas; //get方法 public List<Data> getDatas() { return datas; } //set方法 public void setDatas(List<Data> datas) { this.datas = datas; } //构造函数，初始化数据 public DefaultAdapter(List<Data> datas) { this.datas = datas; } @Override public int getCount() { // TODO Auto-generated method stub return datas.size(); } @Override public Object getItem(int position) { // TODO Auto-generated method stub return datas.get(position); } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { //BaseHolder使用泛型以支持多种数据类型的Holder BaseHolder<Data> holder; if(convertView == null){ //每一个栏目的holder不一样,因此让子类去实现，让每一个子类返回自己的ViewHolder来获取到子类的Holder holder = getHolder(); }else{ holder = (BaseHolder) convertView.getTag(); } Data data = datas.get(position); holder.setData(data); return holder.getContentView(); } protected abstract BaseHolder<Data> getHolder(); }