我正在使用LazyList用于我的自定义ListView，其中包含ImageView和TextView。它几乎没有加载一些图像，有时它会给我错误。
ImageLoader：
public class ImageLoader {
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
Handler handler = new Handler();// handler to display images in UI thread
public ImageLoader(Context context) {
fileCache = new FileCache(context);
executorService = Executors.newFixedThreadPool(5);
}
final int stub_id = R.drawable.ic_launcher;
public void DisplayImage(String url, ImageView imageView) {
imageViews.put(imageView, url);
Bitmap bitmap = memoryCache.get(url);
if (bitmap != null)
imageView.setImageBitmap(bitmap);
else {
queuePhoto(url, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, ImageView imageView) {
PhotoToLoad p = new PhotoToLoad(url, imageView);
executorService.submit(new PhotosLoader(p));
}
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);
conn.setInstanceFollowRedirects(true);
InputStream is = conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
conn.disconnect();
bitmap = decodeFile(f);
return bitmap;
} catch (Throwable ex) {
ex.printStackTrace();
if (ex instanceof OutOfMemoryError)
memoryCache.clear();
return null;
}
}
// 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;
FileInputStream stream1 = new FileInputStream(f);
BitmapFactory.decodeStream(stream1, null, o);
stream1.close();
// 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;
FileInputStream stream2 = new FileInputStream(f);
Bitmap bitmap = BitmapFactory.decodeStream(stream2, null, o2);
stream2.close();
return bitmap;
} catch (FileNotFoundException e) {
} catch (IOException e) {
e.printStackTrace();
}
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;
}
}
class PhotosLoader implements Runnable {
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad) {
this.photoToLoad = photoToLoad;
}
@Override
public void run() {
try {
if (imageViewReused(photoToLoad))
return;
Bitmap bmp = getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
if (imageViewReused(photoToLoad))
return;
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
handler.post(bd);
} catch (Throwable th) {
th.printStackTrace();
}
}
}
boolean imageViewReused(PhotoToLoad photoToLoad) {
String tag = imageViews.get(photoToLoad.imageView);
if (tag == null || !tag.equals(photoToLoad.url))
return true;
return false;
}
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
PhotoToLoad photoToLoad;
public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
bitmap = b;
photoToLoad = p;
}
public void run() {
if (imageViewReused(photoToLoad))
return;
if (bitmap != null)
photoToLoad.imageView.setImageBitmap(bitmap);
else
photoToLoad.imageView.setImageResource(stub_id);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
}
LogCat：
05-29 13:54:25.263: W/System.err(20615): java.net.SocketTimeoutException
05-29 13:54:25.263: W/System.err(20615): at java.net.PlainSocketImpl.read(PlainSocketImpl.java:491)
05-29 13:54:25.263: W/System.err(20615): at java.net.PlainSocketImpl.access$000(PlainSocketImpl.java:46)
05-29 13:54:25.263: W/System.err(20615): at java.net.PlainSocketImpl$PlainSocketInputStream.read(PlainSocketImpl.java:240)
05-29 13:54:25.263: W/System.err(20615): at java.io.InputStream.read(InputStream.java:163)
05-29 13:54:25.263: W/System.err(20615): at java.io.BufferedInputStream.fillbuf(BufferedInputStream.java:142)
05-29 13:54:25.263: W/System.err(20615): at java.io.BufferedInputStream.read(BufferedInputStream.java:227)
05-29 13:54:25.263: W/System.err(20615): at libcore.io.Streams.readAsciiLine(Streams.java:201)
05-29 13:54:25.263: W/System.err(20615): at libcore.net.http.HttpEngine.readResponseHeaders(HttpEngine.java:560)
05-29 13:54:25.263: W/System.err(20615): at libcore.net.http.HttpEngine.readResponse(HttpEngine.java:813)
05-29 13:54:25.263: W/System.err(20615): at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:274)
05-29 13:54:25.263: W/System.err(20615): at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:168)
05-29 13:54:25.263: W/System.err(20615): at com.mytestbuddy.teacher.ImageLoader.getBitmap(ImageLoader.java:72)
05-29 13:54:25.263: W/System.err(20615): at com.mytestbuddy.teacher.ImageLoader.access$0(ImageLoader.java:55)
05-29 13:54:25.263: W/System.err(20615): at com.mytestbuddy.teacher.ImageLoader$PhotosLoader.run(ImageLoader.java:147)
05-29 13:54:25.263: W/System.err(20615): at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:442)
05-29 13:54:25.273: W/System.err(20615): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
05-29 13:54:25.273: W/System.err(20615): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
05-29 13:54:25.273: W/System.err(20615): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
05-29 13:54:25.273: W/System.err(20615): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
05-29 13:54:25.273: W/System.err(20615): at java.lang.Thread.run(Thread.java:864)
请帮我解决这个问题。
答案 0 :(得分：0)
您应该检查您的互联网连接。当您的互联网连接速度很慢时会发生这种情况。