本文主要講解實現了一個CSDN的安卓客戶端，主要知識點如下

java爬蟲獲取網頁數據

將java程序打包成jar包

Fragment+viewpager+TabPageIndicator實現Tab效果

gestureImageView實現放大縮小圖片

imageLodar實現異步加載圖上

XListView實現下拉刷新

java爬蟲獲取網頁資源

package com.zhy.biz; import java.util.ArrayList; import java.util.List; import org.jsoup.Jsoup; import org.jsoup.nodes.Document; import org.jsoup.nodes.Element; import org.jsoup.select.Elements; import com.zhy.bean.CommonException; import com.zhy.bean.NewsItem; import com.zhy.csdn.DataUtil; import com.zhy.csdn.URLUtil; /** * 處理NewItem的業務類 * @author zhy * */ public class NewsItemBiz { /** * 業界、移動、云計算 * * @param htmlStr * @return * @throws CommonException */ public List<NewsItem> getNewsItems( int newsType , int currentPage) throws CommonException { String urlStr = URLUtil.generateUrl(newsType, currentPage); String htmlStr = DataUtil.doGet(urlStr); List<NewsItem> newsItems = new ArrayList<NewsItem>(); NewsItem newsItem = null; Document doc = Jsoup.parse(htmlStr); Elements units = doc.getElementsByClass("unit"); for (int i = 0; i < units.size(); i++) { newsItem = new NewsItem(); newsItem.setNewsType(newsType); Element unit_ele = units.get(i); Element h1_ele = unit_ele.getElementsByTag("h1").get(0); Element h1_a_ele = h1_ele.child(0); String title = h1_a_ele.text(); String href = h1_a_ele.attr("href"); newsItem.setLink(href); newsItem.setTitle(title); Element h4_ele = unit_ele.getElementsByTag("h4").get(0); Element ago_ele = h4_ele.getElementsByClass("ago").get(0); String date = ago_ele.text(); newsItem.setDate(date); Element dl_ele = unit_ele.getElementsByTag("dl").get(0);// dl Element dt_ele = dl_ele.child(0);// dt try {// 可能沒有圖片 Element img_ele = dt_ele.child(0); String imgLink = img_ele.child(0).attr("src"); newsItem.setImgLink(imgLink); } catch (IndexOutOfBoundsException e) { } Element content_ele = dl_ele.child(1);// dd String content = content_ele.text(); newsItem.setContent(content); newsItems.add(newsItem); } return newsItems; } }

詳細實現參見鏈接

抓取csdn上的各類別的文章 （制作csdn app 二） - Hongyang - 博客頻道 - CSDN.NET

將java項目打包成jar包

參考鏈接：在Eclipse中將Java項目打包為jar - 閔開慧的個人頁面 - 開源中國社區

Fragment+viewpager+TabPageIndicator實現Tab效果

package com.zhy.csdndemo; import com.viewpagerindicator.TabPageIndicator; import android.os.Bundle; import android.support.v4.app.FragmentActivity; import android.support.v4.app.FragmentPagerAdapter; import android.support.v4.view.ViewPager; public class MainActivity extends FragmentActivity { private TabPageIndicator mIndicator ; private ViewPager mViewPager ; private FragmentPagerAdapter mAdapter ; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mIndicator = (TabPageIndicator) findViewById(R.id.id_indicator); mViewPager = (ViewPager) findViewById(R.id.id_pager); mAdapter = new TabAdapter(getSupportFragmentManager()); mViewPager.setAdapter(mAdapter); mIndicator.setViewPager(mViewPager, 0); } }

詳細實現參見鏈接

Android 使用Fragment，ViewPagerIndicator 制作csdn app主要框架 - Hongyang - 博客頻道 - CSDN.NET

viewPager的適配器

package com.zhy.csdndemo;import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentPagerAdapter;public class TabAdapter extends FragmentPagerAdapter {public static final String[] TITLES = new String[] { "業界", "移動", "研發", "程序員雜志", "云計算" };public TabAdapter(FragmentManager fm){super(fm);}@Overridepublic Fragment getItem(int arg0){MainFragment fragment = new MainFragment(arg0+1);return fragment;}@Overridepublic CharSequence getPageTitle(int position){return TITLES[position % TITLES.length];}@Overridepublic int getCount(){return TITLES.length;}}

viewPager中的Fragment實現，其中用xListView實現了獲取數據與刷新等功能

package com.zhy.csdndemo;import java.util.ArrayList; import java.util.List;import me.maxwin.view.IXListViewLoadMore; import me.maxwin.view.IXListViewRefreshListener; import me.maxwin.view.XListView; import android.annotation.SuppressLint; import android.os.AsyncTask; import android.os.Bundle; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup;import com.zhy.bean.CommonException; import com.zhy.bean.NewsItem; import com.zhy.biz.NewsItemBiz; import com.zhy.csdn.Constaint; import com.zhy.csdndemo.adapter.NewsItemAdapter;@SuppressLint("ValidFragment") public class MainFragment extends Fragment implements IXListViewRefreshListener, IXListViewLoadMore {/*** 默認的newType*/private int newsType = Constaint.NEWS_TYPE_YEJIE;/*** 當前頁面*/private int currentPage = 1;/*** 處理新聞的業務類*/private NewsItemBiz mNewsItemBiz;/*** 擴展的ListView*/private XListView mXListView;/*** 數據適配器*/private NewsItemAdapter mAdapter;/*** 數據*/private List<NewsItem> mDatas = new ArrayList<NewsItem>();/*** 獲得newType* @param newsType*/public MainFragment(int newsType){this.newsType = newsType;mNewsItemBiz = new NewsItemBiz();}@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){return inflater.inflate(R.layout.tab_item_fragment_main, null);}@Overridepublic void onActivityCreated(Bundle savedInstanceState){super.onActivityCreated(savedInstanceState);mAdapter = new NewsItemAdapter(getActivity(), mDatas);/*** 初始化*/mXListView = (XListView) getView().findViewById(R.id.id_xlistView);mXListView.setAdapter(mAdapter);mXListView.setPullRefreshEnable(this);mXListView.setPullLoadEnable(this);//mXListView.NotRefreshAtBegin();/*** 進來時直接刷新*/mXListView.startRefresh();}@Overridepublic void onRefresh(){new LoadDatasTask().execute();}@Overridepublic void onLoadMore(){// TODO Auto-generated method stub}/*** 記載數據的異步任務* @author zhy**/class LoadDatasTask extends AsyncTask<Void, Void, Void>{@Overrideprotected Void doInBackground(Void... params){try{List<NewsItem> newsItems = mNewsItemBiz.getNewsItems(newsType, currentPage);mDatas = newsItems;} catch (CommonException e){// TODO Auto-generated catch blocke.printStackTrace();}return null;}@Overrideprotected void onPostExecute(Void result){mAdapter.addAll(mDatas);mAdapter.notifyDataSetChanged();mXListView.stopRefresh();}}}

xListView的adapter,其中使用了imageLoder

package com.zhy.csdndemo.adapter;import java.util.List;import android.content.Context; import android.util.Log; 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 com.nostra13.universalimageloader.core.DisplayImageOptions; import com.nostra13.universalimageloader.core.ImageLoader; import com.nostra13.universalimageloader.core.ImageLoaderConfiguration; import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer; import com.nostra13.universalimageloader.core.display.RoundedBitmapDisplayer; import com.zhy.bean.NewsItem; import com.zhy.csdn.DataUtil; import com.zhy.csdndemo.R;public class NewsItemAdapter extends BaseAdapter {private LayoutInflater mInflater;private List<NewsItem> mDatas;/*** 使用了github開源的ImageLoad進行了數據加載*/private ImageLoader imageLoader = ImageLoader.getInstance();private DisplayImageOptions options;public NewsItemAdapter(Context context, List<NewsItem> datas){this.mDatas = datas;mInflater = LayoutInflater.from(context);imageLoader.init(ImageLoaderConfiguration.createDefault(context));options = new DisplayImageOptions.Builder().showStubImage(R.drawable.images).showImageForEmptyUri(R.drawable.images).showImageOnFail(R.drawable.images).cacheInMemory().cacheOnDisc().displayer(new RoundedBitmapDisplayer(20)).displayer(new FadeInBitmapDisplayer(300)).build();}public void addAll(List<NewsItem> mDatas){this.mDatas.addAll(mDatas);}@Overridepublic int getCount(){return mDatas.size();}@Overridepublic Object getItem(int position){return mDatas.get(position);}@Overridepublic long getItemId(int position){return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent){ViewHolder holder = null;if (convertView == null){convertView = mInflater.inflate(R.layout.news_item_yidong, null);holder = new ViewHolder();holder.mContent = (TextView) convertView.findViewById(R.id.id_content);holder.mTitle = (TextView) convertView.findViewById(R.id.id_title);holder.mDate = (TextView) convertView.findViewById(R.id.id_date);holder.mImg = (ImageView) convertView.findViewById(R.id.id_newsImg);convertView.setTag(holder);} else{holder = (ViewHolder) convertView.getTag();}NewsItem newsItem = mDatas.get(position);holder.mTitle.setText(DataUtil.ToDBC(newsItem.getTitle()));holder.mContent.setText(newsItem.getContent());holder.mDate.setText(newsItem.getDate());if (newsItem.getImgLink() != null){holder.mImg.setVisibility(View.VISIBLE);imageLoader.displayImage(newsItem.getImgLink(), holder.mImg, options);} else{holder.mImg.setVisibility(View.GONE);}return convertView;}private final class ViewHolder{TextView mTitle;TextView mContent;ImageView mImg;TextView mDate;}}

參考鏈接：

客戶端上顯示csdn上的各類別下的的文章列表 （制作csdn app 三） - Hongyang - 博客頻道 - CSDN.NET

效果如下

總結

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