面向holder编程、自动轮询
没有看过上一篇文章的话，建议先去阅读GooglePlay:9.代码抽取（adapter）
项目框架的搭建：
以后每个view都是holder
BaseHolder
public abstract class BaseHolder<Data> {／／写data和t一样
private View contentView;
private Data data;
protected BitmapUtils bitmapUtils;
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);
}MoreHolder
public class MoreHolder extends BaseHolder<Integer> {
public static final int HAS_NO_MORE=0; // 没有额外数据了
public static final int LOAD_ERROR=1;// 加载失败
public static final int HAS_MORE=2;// 有额外数据
private RelativeLayout rl_more_loading,rl_more_error;
/**当Holder显示的时候 显示什么样子*/
@Override
public View initView() {
View view=UiUtils.inflate(R.layout.load_more);
rl_more_loading=(RelativeLayout) view.findViewById(R.id.rl_more_loading);
rl_more_error=(RelativeLayout) view.findViewById(R.id.rl_more_error);
return view;
}
private DefaultAdapter adapter;
public MoreHolder(DefaultAdapter adapter) {
super();
this.adapter=adapter;
}
@Override
public View getContentView() {
loadMore();
return super.getContentView();
}
private void loadMore() {
// 请求服务器 加载下一批数据
// 交给Adapter 让Adapter 加载更多数据
adapter.loadMore();
}
/**根据数据做界面的修改*/
@Override
public void refreshView(Integer data) {
rl_more_error.setVisibility(data==LOAD_ERROR?View.VISIBLE:View.GONE);
rl_more_loading.setVisibility(data==HAS_MORE?View.VISIBLE:View.GONE);
}
}DefaultAdapter ： 多种不同类型条目的ListView
public abstract class DefaultAdapter<Data> extends BaseAdapter {
protected List<Data> datas;
private static final int DEFAULT_ITEM = 0;
private static final int MORE_ITEM = 1;
public List<Data> getDatas() {
return datas;
}
public void setDatas(List<Data> datas) {
this.datas = datas;
}
public DefaultAdapter(List<Data> datas) {
this.datas = datas;
}
@Override
public int getCount() {
return datas.size() + 1; // 最后的一个条目 就是加载更多的条目
}
@Override
public Object getItem(int position) {
return datas.get(position);
}
/** 根据位置 判断当前条目是什么类型 */
@Override
public int getItemViewType(int position) { //20
if (position == datas.size()) { // 当前是最后一个条目
return MORE_ITEM;
}
return getInnerItemViewType(position); // 如果不是最后一个条目 返回默认类型
}
private int getInnerItemViewType(int position) {
return DEFAULT_ITEM;
}
/** 当前ListView 有几种不同的条目类型 */
@Override
public int getViewTypeCount() {
return super.getViewTypeCount() + 1; // 2 有两种不同的类型
}
@Override
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
BaseHolder holder = null;
switch (getItemViewType(position)) { // 判断当前条目时什么类型
case MORE_ITEM:
if(convertView==null){
holder=getMoreHolder();
}else{
holder=(BaseHolder) convertView.getTag();
}
break;
case DEFAULT_ITEM:
if (convertView == null) {
holder = getHolder();
} else {
holder = (BaseHolder) convertView.getTag();
}
if (position < datas.size()) {
holder.setData(datas.get(position));
}
break;
}
return holder.getContentView(); // 如果当前Holder 恰好是MoreHolder 证明MoreHOlder已经显示
}
private MoreHolder holder;
private BaseHolder getMoreHolder() {
if(holder!=null){
return holder;
}else{
holder=new MoreHolder(this);
return holder;
}
}
protected abstract BaseHolder<Data> getHolder();
/**
* 当加载更多条目显示的时候 调用该方法
*/
public void loadMore() {
ThreadManager.getInstance().createLongPool().execute(new Runnable() {
@Override
public void run() {
// 在子线程中加载更多
final List<Data> newData = onload();
UiUtils.runOnUiThread(new Runnable() {
@Override
public void run() {
if(newData==null){
holder.setData(MoreHolder.LOAD_ERROR);//
}else if(newData.size()==0){
holder.setData(MoreHolder.HAS_NO_MORE);
}else{
// 成功了
holder.setData(MoreHolder.HAS_MORE);
datas.addAll(newData);// 给listView之前的集合添加一个新的集合
notifyDataSetChanged();// 刷新界面
}
}
});
}
});
}
/**
* 加载更多数据
*/
protected abstract List<Data> onload();
}
修改8的代码SubjectFragment
public class SubjectFragment extends BaseFragment {
private List<SubjectInfo> datas;
@Override
public View createSuccessView() {
BaseListView listView=new BaseListView (UiUtils.getContext());
listView.setAdapter(new SubjectAdapter(datas));
return listView;
}
private class SubjectAdapter extends DefaultAdapter<SubjectInfo>{
public SubjectAdapter(List<SubjectInfo> datas) {
super(datas);
}
@Override
protected BaseHolder<SubjectInfo> getHolder() {
return new SubjectHolder();
}
@Override
protected List<SubjectInfo> onload() {
SubjectProtocol protocol=new SubjectProtocol();
List<SubjectInfo> load = protocol.load(0);
datas.addAll(load);
return load;
}
}
class SubjectHolder extends BaseHolder<SubjectInfo>{
ImageView item_icon;
TextView item_txt;
@Override
public View initView() {
View contentView=UiUtils.inflate(R.layout.item_subject);
this.item_icon=(ImageView) contentView.findViewById(R.id.item_icon);
this.item_txt=(TextView) contentView.findViewById(R.id.item_txt);
return contentView;
}
@Override
public void refreshView(SubjectInfo data) {
this.item_txt.setText(data.getDes());
bitmapUtils.display(this.item_icon, HttpHelper.URL+"image?name="+data.getUrl());
}
}
@Override
protected LoadResult load() {
SubjectProtocol protocol=new SubjectProtocol();
datas = protocol.load(0);
return checkData(datas);
}
}都是首页、APP、游戏页面很相似，所有又可以抽取
ListBaseHolder
public class ListBaseHolder extends BaseHolder<AppInfo> {
ImageView item_icon;
TextView item_title,item_size,item_bottom;
RatingBar item_rating;
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(); //http://127.0.0.1:8090/image?name=app/com.youyuan.yyhl/icon.jpg
// 显示图片的控件
bitmapUtils.display(this.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;
}
}ListBaseAdapter
public abstract class ListBaseAdapter extends DefaultAdapter<AppInfo> {
public ListBaseAdapter(List<AppInfo> datas) {
super(datas);
}
@Override
protected BaseHolder<AppInfo> getHolder() {
return new ListBaseHolder();
}
@Override
protected abstract List<AppInfo> onload();
}GameFragment
public class GameFragment extends BaseFragment {
private List<AppInfo> datas;
/**
* 加载成功的界面
*/
@Override
public View createSuccessView() {
BaseListView listView=new BaseListView(UiUtils.getContext());
listView.setAdapter(new ListBaseAdapter(datas){
@Override
protected List<AppInfo> onload() {
GameProtocol protocol=new GameProtocol();
List<AppInfo> load = protocol.load(datas.size()); //
datas.addAll(load);
return load;
}
});
return listView;
}
/**
* 请求服务器加载数据
*/
@Override
protected LoadResult load() {
GameProtocol protocol=new GameProtocol();
datas = protocol.load(0);
return checkData(datas);
}
}AppFragment
public class AppFragment extends BaseFragment {
private List<AppInfo> datas;
/**
* 当加载成功的时候 显示的界面
*/
@Override
public View createSuccessView() {
BaseListView listView=new BaseListView(UiUtils.getContext());
listView.setAdapter(new ListBaseAdapter(datas){
@Override
protected List<AppInfo> onload() {
AppProtocol protocol=new AppProtocol();
List<AppInfo> load = protocol.load(0);
datas.addAll(load);
return load;
}
});
return listView;
}
/**
* 请求服务器 获取服务器的数据
*/
protected LoadResult load() {
AppProtocol protocol=new AppProtocol();
datas = protocol.load(0);
return checkData(datas); // 检查数据 有三种结果 成功, 错误,空
}
}首页有个几张图片的展示栏，所以又是一个holder
HomePictureHolder （自动轮询）
public class HomePictureHolder extends BaseHolder<List<String>> {
/* 当new HomePictureHolder()就会调用该方法 */
private ViewPager viewPager;
private List<String> datas;
@Override
public View initView() {
viewPager = new ViewPager(UiUtils.getContext());
viewPager.setLayoutParams(new AbsListView.LayoutParams(
LayoutParams.MATCH_PARENT, UiUtils
.getDimens(R.dimen.home_picture_height)));／／转换成dp
return viewPager;
}
/* 当 holder.setData 才会调用 */
@Override
public void refreshView(List<String> datas) {
this.datas = datas;
viewPager.setAdapter(new HomeAdapter());
viewPager.setCurrentItem(2000*datas.size());// 设置起始的位置 Integer.Max_Vlue/2，这样开始位置也能向后划了
viewPager.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
runTask.stop();
break;
// 事件的取消，有可能按下viewpager滑动到listview上停止就不轮播了
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
runTask.start();
break;
}
return false; // viewPager 触摸事件 返回值要是false
}
});
runTask = new AuToRunTask();
runTask.start();
}
boolean flag;
private AuToRunTask runTask;
//Runnable并不是开启子线程，所以可以在主线程运行，thread才是开启线程
public class AuToRunTask implements Runnable{
@Override
public void run() {
if(flag){
UiUtils.cancel(this); // 取消之前
int currentItem = viewPager.getCurrentItem();
currentItem++;
viewPager.setCurrentItem(currentItem);
// 延迟执行当前的任务
UiUtils.postDelayed(this, 2000);// 递归调用
}
}
public void start(){
if(!flag){
UiUtils.cancel(this); // 取消之前
flag=true;
UiUtils.postDelayed(this, 2000);// 递归调用
}
}
public void stop(){
if(flag){
flag=false;
UiUtils.cancel(this);
}
}
}
class HomeAdapter extends PagerAdapter {
// 当前viewPager里面有多少个条目
LinkedList<ImageView> convertView=new LinkedList<ImageView>();
// ArrayList
@Override
public int getCount() {
return Integer.MAX_VALUE;／／这样写条目就能一直划了
}
/* 判断返回的对象和 加载view对象的关系 */
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
ImageView view=(ImageView) object;
convertView.add(view);// 把移除的对象 添加到缓存集合中
container.removeView(view);
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
int index=position%datas.size();／／访问网络需要这个参数
ImageView view;
if(convertView.size()>0){
view=convertView.remove(0);
}else{
view= new ImageView(UiUtils.getContext());
}
bitmapUtils.display(view, HttpHelper.URL + "image?name="
+ datas.get(index));
container.addView(view); // 加载的view对象
return view; // 返回的对象
}
}
}UiUtils 添加这三个方法
/**
* 延迟执行 任务
* @param run 任务
* @param time 延迟的时间
*/
public static void postDelayed(Runnable run, int time) {
BaseApplication.getHandler().postDelayed(run, time); // 调用Runable里面的run方法
}
/**
* 取消任务
* @param auToRunTask
*/
public static void cancel(Runnable auToRunTask) {
BaseApplication.getHandler().removeCallbacks(auToRunTask);
}
}
这样写获取到图片高的dp
<dimen name="home_picture_height">134dp</dimen>
public static int getDimens(int homePictureHeight) {
return (int) getResource().getDimension(homePictureHeight);
}HomeFragment
public class HomeFragment extends BaseFragment {
private List<AppInfo> datas;
private List<String> pictures; // 顶部ViewPager 显示界面的数据
// 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() {
BaseListView listView=new BaseListView(UiUtils.getContext());
HomePictureHolder holder=new HomePictureHolder();
holder.setData(pictures);
View contentView = holder.getContentView(); // 得到holder里面管理的view对象
//contentView.setLayoutParams(new AbsListView.LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT));
listView.addHeaderView(contentView); // 把holder里的view对象 添加到listView的上面
listView.setAdapter(new ListBaseAdapter(datas,listView){
@Override
protected List<AppInfo> onload() {
HomeProtocol protocol=new HomeProtocol();
List<AppInfo> load = protocol.load(datas.size());
datas.addAll(load);
return load;
}
@Override
public void onInnerItemClick(int position) {
super.onInnerItemClick(position);
Toast.makeText(getActivity(), "position:"+position, 0).show();
AppInfo appInfo = datas.get(position);
Intent intent=new Intent(UiUtils.getContext(), DetailActivity.class);
intent.putExtra("packageName", appInfo.getPackageName());//将包名传到详情页，详情页访问网络用包名
startActivity(intent);
}
});
// 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;
}
public LoadResult load() {
HomeProtocol protocol=new HomeProtocol();
datas = protocol.load(0); // load index 从哪个位置开始获取数据 0 20 40 60
pictures = protocol.getPictures();
return checkData(datas);
}
}修改DefaultAdapter，这样传调到详情页面的时候position
已经是修改过的了，我们并不希望去点首页的图片展示
public DefaultAdapter(List<Data> datas,ListView lv) {
this.datas = datas;
// 给ListView设置条目的点击事件
lv.setOnItemClickListener(this);
this.lv=lv;
}
// ListView 条目点击事件回调的方法
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
//Toast.makeText(UiUtils.getContext(), "position:"+position, 0).show();
position=position-lv.getHeaderViewsCount();// 获取到顶部条目的数量 位置去掉顶部view的数量
onInnerItemClick(position);
}
/**在该方法去处理条目的点击事件*/
public void onInnerItemClick(int position) {
}面向holder编程
public View createSuccessView() {
BaseListView listView=new BaseListView(UiUtils.getContext());
HomePictureHolder holder=new HomePictureHolder();
holder.setData(pictures);
View contentView = holder.getContentView(); // 得到holder里面管理的view对象
contentView.setLayoutParams(new AbsListView.LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT));
listView.addHeaderView(contentView); // 把holder里的view对象 添加到listView的上面本文参与 腾讯云自媒体分享计划，分享自作者个人站点/博客。
原始发表：2015-11-17 ，如有侵权请联系 cloudcommunity@tencent.com 删除
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