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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