实例介绍
【实例简介】
【实例截图】
【核心代码】
package com.my; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import android.app.Activity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.AsyncTask; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.util.Log; import android.view.KeyEvent; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.AdapterView.OnItemSelectedListener; import android.widget.Gallery; public class MyActivity extends Activity implements OnItemClickListener { public static HashMap<String, Bitmap> imagesCache = new HashMap<String, Bitmap>(); // 图片缓存 private Gallery images_ga; public static ImageAdapter imageAdapter; private int num = 0; List<String> urls = new ArrayList<String>(); // 所有图片地址List List<String> url = new ArrayList<String>(); // 需要下载图片的url地址 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.gallery_1); Files.mkdir(this); init(); } private void init() { Bitmap image = BitmapFactory.decodeResource(getResources(), R.drawable.default_movie_post); imagesCache.put("background_non_load", image); // 设置缓存中默认的图片 images_ga = (Gallery) findViewById(R.id.gallery); urls.add("http://hiphotos.baidu.com/baidu/pic/item/f603918fa0ec08fabf7a641659ee3d6d55fbda0d.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/43a7d933c895d143d011bf9273f082025aaf071f.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/63d0f703918fa0ec2ebf584b269759ee3d6ddb7f.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/5ab5c9ea15ce36d31ed8387f3af33a87e850b1a5.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/8601a18b87d6277f6e46217628381f30e924fc2c.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/b48f8c54acf9964c3a29350e.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/bd3eb13533fa828b48da6aabfd1f4134960a5af9.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/29381f30e924b899da3ce5706e061d950a7bf672.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/bd3eb13533fa828b48da6aabfd1f4134960a5af9.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/4bed2e738bd4b31cd73d63fd87d6277f9e2ff877.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/caef76094b36acaf92b619b87cd98d1001e99c24.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/8435e5dde71190efd6154d95ce1b9d16fcfa608a.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/b3de9c824ba1d4cd6d81190f.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/e0fe9925cc2c683834a80f11.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/0bd162d9f2d3572c65911a988a13632762d0c307.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/ac6eddc451da81cb2ac1708a5266d01609243155.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/1bd5ad6e8416d98080cb4a48.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/3c6d55fbb2fb43169d0508ca20a4462309f7d36c.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/faedab64034f78f0daf3664a79310a55b2191c8a.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/2fdda3cc7cd98d10b05af088213fb80e7aec90f9.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/b8014a90f603738d9536f39bb31bb051f819ec0f.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/2fdda3cc7cd98d10b05af088213fb80e7aec90f9.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/f603918fa0ec08fabf7a641659ee3d6d55fbda0d.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/43a7d933c895d143d011bf9273f082025aaf071f.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/63d0f703918fa0ec2ebf584b269759ee3d6ddb7f.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/5ab5c9ea15ce36d31ed8387f3af33a87e850b1a5.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/8601a18b87d6277f6e46217628381f30e924fc2c.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/b48f8c54acf9964c3a29350e.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/bd3eb13533fa828b48da6aabfd1f4134960a5af9.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/29381f30e924b899da3ce5706e061d950a7bf672.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/bd3eb13533fa828b48da6aabfd1f4134960a5af9.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/4bed2e738bd4b31cd73d63fd87d6277f9e2ff877.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/caef76094b36acaf92b619b87cd98d1001e99c24.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/8435e5dde71190efd6154d95ce1b9d16fcfa608a.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/b3de9c824ba1d4cd6d81190f.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/e0fe9925cc2c683834a80f11.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/0bd162d9f2d3572c65911a988a13632762d0c307.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/ac6eddc451da81cb2ac1708a5266d01609243155.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/1bd5ad6e8416d98080cb4a48.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/3c6d55fbb2fb43169d0508ca20a4462309f7d36c.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/faedab64034f78f0daf3664a79310a55b2191c8a.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/2fdda3cc7cd98d10b05af088213fb80e7aec90f9.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/b8014a90f603738d9536f39bb31bb051f819ec0f.jpg"); urls.add("http://hiphotos.baidu.com/baidu/pic/item/2fdda3cc7cd98d10b05af088213fb80e7aec90f9.jpg"); imageAdapter = new ImageAdapter(urls, this); images_ga.setAdapter(imageAdapter); images_ga.setOnItemClickListener(this); images_ga.setOnItemSelectedListener(new OnItemSelectedListener() { @Override public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) { num = arg2; Log.i("mahua", "ItemSelected==" arg2); GalleryWhetherStop(); } @Override public void onNothingSelected(AdapterView<?> arg0) { // TODO Auto-generated method stub } }); } @Override public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) { Log.i("GOLF", "第" arg2 "个被点击了"); } /** * 判断Gallery滚动是否停止,如果停止则加载当前页面的图片 */ private void GalleryWhetherStop() { Runnable runnable = new Runnable() { public void run() { try { int index = 0; index = num; Thread.sleep(1000); if (index == num) { url.add(urls.get(num)); if (num != 0 && urls.get(num - 1) != null) { url.add(urls.get(num - 1)); } if (num != urls.size() - 1 && urls.get(num 1) != null) { url.add(urls.get(num 1)); } Message m = new Message(); m.what = 1; mHandler.sendMessage(m); } } catch (Exception e) { e.printStackTrace(); } } }; new Thread(runnable).start(); } // 加载图片的异步任务 class LoadImageTask extends AsyncTask<String, Void, Bitmap> { @Override protected void onCancelled() { // TODO Auto-generated method stub super.onCancelled(); } @Override protected void onPostExecute(Bitmap result) { // TODO Auto-generated method stub super.onPostExecute(result); } @Override protected Bitmap doInBackground(String... params) { Bitmap bitmap = null; try { String url = params[0]; boolean isExists = Files.compare(url); if (isExists == false) { Net net = new Net(); byte[] data = net.downloadResource(MyActivity.this, url); bitmap = BitmapFactory .decodeByteArray(data, 0, data.length); imagesCache.put(url, bitmap); // 把下载好的图片保存到缓存中 Files.saveImage(url, data); } else { byte[] data = Files.readImage(url); bitmap = BitmapFactory .decodeByteArray(data, 0, data.length); imagesCache.put(url, bitmap); // 把下载好的图片保存到缓存中 } Message m = new Message(); m.what = 0; mHandler.sendMessage(m); } catch (Exception e) { e.printStackTrace(); } return bitmap; } } private Handler mHandler = new Handler() { public void handleMessage(Message msg) { try { switch (msg.what) { case 0: { imageAdapter.notifyDataSetChanged(); break; } case 1: { for (int i = 0; i < url.size(); i ) { LoadImageTask task = new LoadImageTask();// 异步加载图片 task.execute(url.get(i)); Log.i("mahua", url.get(i)); } url.clear(); } } super.handleMessage(msg); } catch (Exception e) { e.printStackTrace(); } } }; @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_BACK) { System.exit(0); } return super.onKeyDown(keyCode, event); } }
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