import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.URL;
/**
* 網絡工具類
*
* @author Administrator
*
*/
public class NetUtils {
/**
* 通過get請求 獲取字符數據流
*
* @param path
* @return
*/
public static Reader getDataByGet(String path) {
InputStreamReader isr = null;
try {
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
int code = conn.getResponseCode();
if (code == 200) {
InputStream is = conn.getInputStream();
isr = new InputStreamReader(is);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return isr;
}
}=========================================================
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 android.app.Application;
public class MyApp extends Application {
@Override
public void onCreate() {
DisplayImageOptions options = new DisplayImageOptions.Builder()
.showImageOnLoading(R.drawable.ic_launcher)
.displayer(new FadeInBitmapDisplayer(2000)).cacheOnDisk(true)
.cacheInMemory(true).build();
ImageLoaderConfiguration configs = new ImageLoaderConfiguration.Builder(
this).defaultDisplayImageOptions(options).threadPoolSize(5)
.build();
ImageLoader.getInstance().init(configs);
super.onCreate();
}
}
=============================================================
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import com.example.day11demo.bean.News;
import com.example.day11demo.bean.NewsData;
import com.example.day11demo.net.NetUtils;
import com.google.gson.Gson;
import com.nostra13.universalimageloader.core.ImageLoader;
@SuppressLint("NewApi")
public class MainActivity extends Activity {
ListView lv;
NewsData nd;
List<News> list;
MyAdapter adapter;
// 表示當前加載的頁面
int mCurrentPage = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 1、顯示listview控件 加載網絡數據
lv = (ListView) findViewById(R.id.lv);
initData();
adapter = new MyAdapter();
lv.setAdapter(adapter);
// listview的滑動監聽 可以用作加載更多
lv.setOnScrollListener(new OnScrollListener() {
// 當滑動到最後一個條的時候 listview會從 滾動狀態變成靜止狀態 屬於狀態的改變
// 所以當listview滑動最後一個條 狀態改變監聽的方法肯定會被調用
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
switch (scrollState) {
case OnScrollListener.SCROLL_STATE_IDLE:
if (view.getLastVisiblePosition() == list.size() - 1) {
// 先把當前頁面 +1
mCurrentPage++;
// 調用加載更多方法
loadMoreData();
}
break;
default:
break;
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
}
});
}
private void initData() {
// 用來讓listview進行顯示的數據集合
list = new ArrayList<News>();
// 使用一個加載更多的方法請求10條數據
loadMoreData();
}
// 每次加載10條數據 然後把這十條數據存入一個 list集合中 刷新適配器進行顯示
private void loadMoreData() {
new AsyncTask<String, String, NewsData>() {
@Override
protected NewsData doInBackground(String... params) {
// 通過get方式請求 網絡的字符輸入流
Reader reader = NetUtils
.getDataByGet("https://api.tianapi.com/wxnew/?key=8d6e3228d25298f13af4fc40ce6c9679&num=10&page="
+ mCurrentPage);
Gson gson = new Gson();
nd = gson.fromJson(reader, NewsData.class);
// 因爲該loadmore方法每次加載都是把10條數據轉換成javabean對象
// 所以我們需要一個單獨的list集合 然後把每次請就回來的javabean中集合的數據 全都拼接到單獨結合中
list.addAll(nd.getNewslist());
return null;
}
protected void onPostExecute(NewsData result) {
// 刷新
adapter.notifyDataSetChanged();
};
}.execute();
}
class MyAdapter extends BaseAdapter {
@Override
public int getCount() {
// TODO Auto-generated method stub
return list.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = View.inflate(MainActivity.this,
R.layout.list_itme, null);
holder = new ViewHolder();
holder.tv_title = (TextView) convertView
.findViewById(R.id.tv_title);
holder.tv_desc = (TextView) convertView
.findViewById(R.id.tv_desc);
holder.tv_time = (TextView) convertView
.findViewById(R.id.tv_time);
holder.iv = (ImageView) convertView.findViewById(R.id.iv);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.tv_time.setText(list.get(position).getCtime());
holder.tv_desc.setText(list.get(position).getDescription());
holder.tv_title.setText(list.get(position).getTitle());
ImageLoader.getInstance().displayImage(
list.get(position).getPicUrl(), holder.iv);
return convertView;
}
}
public static class ViewHolder {
TextView tv_title;
TextView tv_desc;
TextView tv_time;
ImageView iv;
}
}