正在寻找如何将服务器的图像有效装入我的包裹。 权利现在是指使用电荷载技术在。
但是,当彩色图像数量增加时,情况仍会放缓。 任何人都可以找到或利用任何其他技术。 此外,我不理解有些社会网络像POF和匹配.com等,是如何在图像最初被模仿展示并取得良好质量的地方实施。 希望你们能够理解我的问题。 寻求更好的对策。 预付款。
Edit #1:
Sorry Guys i just have pasted different url above... This is the one which i have followed for my implementation
Also went through the first url and found they also have used the same logic...
Edit #2:
gallery.setAdapter(new LazyGalleryBaseAdapter(this, mStrings));
imageLoader.DisplayImage(data[position], activity, image);// called from the getview method of LazyGalleryBaseAdapter class
图像分解类别如下:
package com.sdi.lazyimageloader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.Stack;
import java.util.WeakHashMap;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;
import com.sdi.videodate.R;
public class ImageLoader {
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
Context ctx;
public ImageLoader(Context context) {
// Make the background thead low priority. This way it will not affect
// the UI performance
photoLoaderThread.setPriority(Thread.NORM_PRIORITY - 1);
ctx = context;
fileCache = new FileCache(context);
}
final int stub_id = R.drawable.stub;
public void DisplayImage(String url, Activity activity, ImageView imageView) {
imageViews.put(imageView, url);
Bitmap bitmap = memoryCache.get(url);
System.err.println("bitmap ??????"+bitmap);
System.out.println("imageView ===> "+imageView);
if (bitmap != null) {
// call the below line to get the rounded corner image
// Bitmap bitmap1 = LazyAdapter.getRoundedCornerBitmap(ctx, bitmap,
// 7f, 7f, 7f, 7f, 85, 85);
imageView.setImageBitmap(bitmap);
} else {
queuePhoto(url, activity, imageView);
imageView.setImageResource(stub_id);
System.err.println("bitmap stub_id??????"+stub_id);
}
}
private void queuePhoto(String url, Activity activity, ImageView imageView) {
// This ImageView may be used for other images before. So there may be
// some old tasks in the queue. We need to discard them.
photosQueue.Clean(imageView);
PhotoToLoad p = new PhotoToLoad(url, imageView);
synchronized (photosQueue.photosToLoad) {
photosQueue.photosToLoad.push(p);
photosQueue.photosToLoad.notifyAll();
}
// start thread if it s not started yet
if (photoLoaderThread.getState() == Thread.State.NEW)
photoLoaderThread.start();
}
private Bitmap getBitmap(String url) {
File f = fileCache.getFile(url);
// from SD cache
Bitmap b = decodeFile(f);
if (b != null)
return b;
// from web
try {
Bitmap bitmap = null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) imageUrl
.openConnection();
conn.setConnectTimeout(30000);
conn.setReadTimeout(30000);
InputStream is = conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
bitmap = decodeFile(f);
return bitmap;
} catch (Exception ex) {
ex.printStackTrace();
return null;
}
}
private static Bitmap decodeFiles(File f) {
Bitmap b = null;
try {
// Decode image size
int IMAGE_MAX_SIZE = 80;
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
FileInputStream fis = new FileInputStream(f);
BitmapFactory.decodeStream(fis, null, o);
try {
fis.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int scale = 1;
if (o.outHeight <= 1300 && o.outWidth <= 1000) {
scale = 1;
} else if (o.outHeight >= 1280 && o.outWidth >= 960) {
scale = 6;
} else if (o.outHeight > IMAGE_MAX_SIZE
|| o.outWidth > IMAGE_MAX_SIZE) {
// scale = (int) Math.pow(2,(int)
// Math.round(Math.log(IMAGE_MAX_SIZE / (double)
// Math.max(o.outHeight, o.outWidth))/ Math.log(0.5)));
scale = 5;
}
/*
* else if (o.outHeight > IMAGE_MAX_SIZE || o.outWidth >
* IMAGE_MAX_SIZE) { // scale = (int) Math.pow( 2,(int) //
* Math.round(Math.log(IMAGE_MAX_SIZE / (double) //
* Math.max(o.outHeight, o.outWidth))/ Math.log(0.5))); scale = 8; }
*/
System.err.println(scale
+ "---Scale Value (((((((((((((((((((((((((((((("
+ o.outHeight + "---" + o.outWidth);
// Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
fis = new FileInputStream(f);
try{
b = BitmapFactory.decodeStream(fis, null, o2);
}
catch (OutOfMemoryError e) {
// TODO: handle exception
}
try {
fis.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return b;
}
// decodes image and scales it to reduce memory consumption
/*
* rename by dinash from decodeFile to decodeFiles
*/
private Bitmap decodeFile(File f) {
try {
// decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FileInputStream(f), null, o);
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE = 70;
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp / 2 < REQUIRED_SIZE
|| height_tmp / 2 < REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale *= 2;
}
// decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
try{
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
}
catch (OutOfMemoryError e) {
// TODO: handle exception
}
} catch (FileNotFoundException e) {
}
return null;
}
// Task for the queue
private class PhotoToLoad {
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i) {
url = u;
imageView = i;
}
}
PhotosQueue photosQueue = new PhotosQueue();
public void stopThread() {
photoLoaderThread.interrupt();
}
// stores list of photos to download
class PhotosQueue {
private Stack<PhotoToLoad> photosToLoad = new Stack<PhotoToLoad>();
// removes all instances of this ImageView
public void Clean(ImageView image) {
for (int j = 0; j < photosToLoad.size();) {
if (photosToLoad.get(j).imageView == image)
photosToLoad.remove(j);
else
++j;
}
}
}
class PhotosLoader extends Thread {
public void run() {
try {
while (true) {
// thread waits until there are any images to load in the
// queue
if (photosQueue.photosToLoad.size() == 0)
synchronized (photosQueue.photosToLoad) {
photosQueue.photosToLoad.wait();
}
if (photosQueue.photosToLoad.size() != 0) {
PhotoToLoad photoToLoad;
synchronized (photosQueue.photosToLoad) {
photoToLoad = photosQueue.photosToLoad.pop();
}
Bitmap bmp = getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
String tag = imageViews.get(photoToLoad.imageView);
if (tag != null && tag.equals(photoToLoad.url)) {
BitmapDisplayer bd = new BitmapDisplayer(bmp,
photoToLoad.imageView);
Activity a = (Activity) photoToLoad.imageView
.getContext();
a.runOnUiThread(bd);
}
}
if (Thread.interrupted())
break;
}
} catch (InterruptedException e) {
// allow thread to exit
}
}
}
PhotosLoader photoLoaderThread = new PhotosLoader();
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
ImageView imageView;
public BitmapDisplayer(Bitmap b, ImageView i) {
bitmap = b;
imageView = i;
}
public void run() {
System.out.println("imageView ===> "+imageView);
if (bitmap != null)
imageView.setImageBitmap(bitmap);
else
imageView.setImageResource(stub_id);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
}