my logcat---------::
09-07 19:55:51.623: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:55:51.634: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:55:52.033: DEBUG/dalvikvm(1680): GC_FOR_MALLOC freed 1896 objects / 518112 bytes in 97ms
09-07 19:55:52.364: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:55:53.254: DEBUG/dalvikvm(1680): GC_FOR_MALLOC freed 822 objects / 539696 bytes in 67ms
09-07 19:56:01.514: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805085124_wtpa.logo.png
09-07 19:56:01.584: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805084621_wtpa.logo.png
09-07 19:56:01.643: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805025050_chuckie liv.ashx.jpg
09-07 19:56:01.684: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805024007_space vegas.ashx.jpg
09-07 19:56:01.914: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:56:01.953: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:56:02.714: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:56:02.754: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805023407_blush vegas.ashx.jpg
09-07 19:56:02.834: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805022856_Savoy vegas.ashx.jpg
09-07 19:56:02.944: DEBUG/dalvikvm(1680): GC_FOR_MALLOC freed 1058 objects / 490016 bytes in 80ms
09-07 19:56:02.944: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:56:02.944: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:56:03.894: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:56:03.923: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110808101519_DSC0028-Ti.jpg
09-07 19:56:04.104: INFO/System.out(1680): ImageUrl :: http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110729152914_wtpa.logo.png
09-07 19:56:04.604: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:56:04.634: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:56:05.004: DEBUG/dalvikvm(1680): GC_FOR_MALLOC freed 966 objects / 515008 bytes in 80ms
09-07 19:56:05.404: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:56:05.434: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:56:05.464: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
09-07 19:56:06.194: DEBUG/skia(1680): --- SkImageDecoder::Factory returned null
我的代码是::
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
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.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.Collections;
import java.util.Map;
import java.util.Stack;
import java.util.WeakHashMap;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.entity.BufferedHttpEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.EventLogTags.Description;
import android.view.View;
import android.widget.ImageView;
import android.widget.ProgressBar;
public class ImageLoader {
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
private ProgressBar indicator;
public ImageLoader(Context context) {
photoLoaderThread.setPriority(Thread.NORM_PRIORITY - 1);
fileCache = new FileCache(context);
}
public void DisplayImage(String url, Context activity, ImageView imageView,
ProgressBar pbar) {
imageViews.put(imageView, url);
Bitmap bitmap = memoryCache.get(url);
if (bitmap != null) {
this.indicator = pbar;
indicator.setVisibility(View.INVISIBLE);
imageView.setImageBitmap(bitmap);
} else {
this.indicator = pbar;
indicator.setVisibility(View.INVISIBLE);
queuePhoto(url, activity, imageView);
imageView.setImageBitmap(null);
}
}
private void queuePhoto(String url, Context 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 {
HttpGet httpRequest = null;
try {
int pos = url.lastIndexOf('/') + 1;
URI uri = new URI(url.substring(0, pos)
+ URLEncoder.encode(url.substring(pos), "UTF-8"));
//URL imgUrl = new URL(decodeUrl);
httpRequest = new HttpGet(uri);
} catch (URISyntaxException e) {
System.out.println("Error ::" + e.toString());
e.printStackTrace();
}
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = (HttpResponse) httpclient
.execute(httpRequest);
HttpEntity entity = response.getEntity();
BufferedHttpEntity bufHttpEntity = new BufferedHttpEntity(entity);
InputStream instream = bufHttpEntity.getContent();
Bitmap bm = BitmapFactory.decodeStream(instream);
/*
* Bitmap bitmap = null; URL imageUrl = new URL(url);
* HttpURLConnection conn = (HttpURLConnection) imageUrl
* .openConnection(); conn.connect(); conn.getDoOutput();
*
*
* 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;
*/
return bm;
} catch (Exception ex) {
ex.printStackTrace();
return null;
}
}
private Bitmap gonextUrl(String url) {
Bitmap bm = null;
try {
URL imgUrl = new URL(url);
HttpGet httpRequest = new HttpGet(imgUrl.toURI());
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = (HttpResponse) httpclient
.execute(httpRequest);
HttpEntity entity = response.getEntity();
BufferedHttpEntity bufHttpEntity = new BufferedHttpEntity(entity);
InputStream instream = bufHttpEntity.getContent();
bm = BitmapFactory.decodeStream(instream);
return bm;
} catch (Exception e) {
e.printStackTrace();
}
return bm;
}
// decodes image and scales it to reduce memory consumption
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;
}
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} 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) {
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, indicator);
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;
// private ProgressBar indicator1;
public BitmapDisplayer(Bitmap b, ImageView i, ProgressBar indicator) {
this.bitmap = b;
this.imageView = i;
// this.indicator1 = indicator;
}
public void run() {
if (bitmap != null) {
// indicator1.setVisibility(View.INVISIBLE);
imageView.setImageBitmap(bitmap);
} else
imageView.setImageBitmap(null);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
}
答案 0 :(得分：0)
调用此函数loadImageFromUrl（“http://www.heresmyparty.com/cms/components/com_chronocontact/uploads/add_event_form/20110805085124_wtpa.logo.png”）从imageurl获取图像位图
public static Bitmap loadImageFromUrl(String url) {
InputStream inputStream;Bitmap b;
try {
inputStream = (InputStream) new URL(url).getContent();
BitmapFactory.Options bpo= new BitmapFactory.Options();
bpo.inSampleSize=2;
b=BitmapFactory.decodeStream(new PatchInputStream(inputStream), null,bpo );
return b;
} catch (IOException e) {
throw new RuntimeException(e);
}
// return null;
}
这是PatchInputStream的类
public class PatchInputStream extends FilterInputStream {
public PatchInputStream(InputStream in) {
super(in);
}
public long skip(long n) throws IOException {
long m = 0L;
while (m < n) {
long _m = in.skip(n-m);
if (_m == 0L) break;
m += _m;
}
return m;
}
}
您还可以修改代码以防止出错。您需要在BitmapFactory.decodeStream中添加PatchInputStream（inputStream）（新的PatchInputStream（inputStream），null，bpo）;