问题
我实现了Custom ListView，它在一个列表视图中有3种不同的布局。
一切正常，直到ListView中的每个项目执行AsyncTask
用于下载图像并在ImageView中设置。虽然这个过程应用程序强制关闭...
注意
我无法在此处提供所有代码，因为它太长了。
然而，自定义ListView的所有过程都工作正常我通过剪切AsyncTask部分测试。
在这种情况下，请假设需要数据已准备好，并且已设置互联网连接。
INTEREST_ADAPTER CLASS
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
ViewHolder_Type1 vh1 = null;
ViewHolder_Type2 vh2 = null;
ViewHolder_Type3 vh3 = null;
int type = getItemViewType(position);
/* initiate setup view */
if (v == null){
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
switch (type) {
case LAYOUT_TYPE1 :
v = inflater.inflate(R.layout.listview_interest_type1,null);
vh1 = new ViewHolder_Type1();
vh1.imgHeading = (ImageView) v.findViewById(R.id.imgHeading);
vh1.imgUser = (ImageView) v.findViewById(R.id.imgUserPic);
vh1.tvHeading = (TextView) v.findViewById(R.id.tvHeading);
vh1.tvUserName = (TextView) v.findViewById(R.id.tvUserName);
vh1.tvPostTime = (TextView) v.findViewById(R.id.tvPostTime);
vh1.tvCategory = (TextView) v.findViewById(R.id.tvCategory);
v.setTag(vh1);
break;
case LAYOUT_TYPE2 :
v = inflater.inflate(R.layout.listview_interest_type2,null);
vh2 = new ViewHolder_Type2();
vh2.imgUser = (ImageView) v.findViewById(R.id.imgUserPic);
vh2.tvHeading = (TextView) v.findViewById(R.id.tvHeading);
vh2.tvBody = (TextView) v.findViewById(R.id.tvBody);
vh2.tvUserName = (TextView) v.findViewById(R.id.tvUserName);
vh2.tvPostTime = (TextView) v.findViewById(R.id.tvPostTime);
vh2.tvCategory = (TextView) v.findViewById(R.id.tvCategory);
v.setTag(vh2);
break;
case LAYOUT_TYPE3 :
v = inflater.inflate(R.layout.listview_interest_type3,null);
vh3 = new ViewHolder_Type3();
vh3.imgGallery = (ImageView) v.findViewById(R.id.imgGallery);
vh3.imgUser = (ImageView) v.findViewById(R.id.imgUserPic);
vh3.tvHeading = (TextView) v.findViewById(R.id.tvTitle);
vh3.tvUserName = (TextView) v.findViewById(R.id.tvUserName);
vh3.tvCategory = (TextView) v.findViewById(R.id.tvCategory);
v.setTag(vh3);
break;
}
} else {
switch (type) {
case LAYOUT_TYPE1 :
vh1 = (ViewHolder_Type1) v.getTag();
break;
case LAYOUT_TYPE2 :
vh2 = (ViewHolder_Type2) v.getTag();
break;
case LAYOUT_TYPE3 :
vh3 = (ViewHolder_Type3) v.getTag();
break;
}
}
/* initiate setup data */
Interest_ListView interestListView = interestListViews.get(position);
String imgHeading = interestListView.img_heading.replaceAll(" ","%20");
String imgGallery = interestListView.img_gallery.replaceAll(" ","%20");
String heading = interestListView.post_heading;
String body = interestListView.post_body;
String username = interestListView.user_name;
String userAvatar = interestListView.user_avatar.replaceAll(" ","%20");
String categories = interestListView.post_categories;
String second = interestListView.second;
String minutes = interestListView.minutes;
String hour = interestListView.hour;
String days = interestListView.days;
switch (type) {
case LAYOUT_TYPE1 :
vh1.tvHeading.setText(heading);
vh1.tvUserName.setText(username);
vh1.tvPostTime.setText(getTime(second, minutes, hour, days));
vh1.tvCategory.setText(categories);
vh1.asyncHeading = new downloadImageTask(vh1.imgHeading, context);
vh1.asyncHeading.execute(imgHeading);
vh1.asyncUser = new downloadImageTask(vh1.imgUser, context);
vh1.asyncUser.execute(imgHeading);
v.setTag(vh1);
break;
case LAYOUT_TYPE2 :
vh2.tvHeading.setText(heading);
vh2.tvBody.setText(body);
vh2.tvUserName.setText(username);
vh2.tvPostTime.setText(getTime(second, minutes, hour, days));
vh2.tvCategory.setText(categories);
vh2.urlUser = userAvatar;
// new downloadImageTask(vh2.imgUser, context).execute(userAvatar);
v.setTag(vh2);
break;
case LAYOUT_TYPE3 :
vh3.tvHeading.setText(heading);
vh3.tvUserName.setText(username);
vh3.tvCategory.setText(categories);
vh3.urlGallery = imgGallery;
vh3.urlUser = userAvatar;
// new downloadImageTask(vh3.imgGallery, context).doInBackground(imgGallery);
// new downloadImageTask(vh3.imgUser, context).doInBackground(userAvatar);
v.setTag(vh3);
break;
}
return v;
}
public static class ViewHolder_Type1{
ImageView imgHeading, imgUser;
TextView tvHeading,tvUserName, tvPostTime, tvCategory;
String urlHeading, urlUser;
downloadImageTask asyncHeading, asyncUser;
}
public static class ViewHolder_Type2{
ImageView imgUser;
TextView tvHeading, tvBody, tvUserName, tvPostTime, tvCategory;
String urlUser;
}
public static class ViewHolder_Type3{
ImageView imgUser, imgGallery;
TextView tvHeading, tvUserName, tvCategory;
String urlUser, urlGallery;
}
private static class downloadImageTask extends AsyncTask<String, Integer, Bitmap> {
ImageView imgContainer;
Context context;
private downloadImageTask(ImageView imgContainer, Context context) {
this.imgContainer = imgContainer;
this.context = context;
}
protected Bitmap doInBackground(String... urls) {
Bitmap getBitmap = null;
int count = urls.length;
for (int i = 0; i < count; i++) {
try {
URL url = new URL(urls[i]);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
getBitmap = BitmapFactory.decodeStream(input); //LINE 256 IS HERE
} catch (IOException e) {
e.printStackTrace();
getBitmap = null;
}
}
return getBitmap;
}
protected void onProgressUpdate(Integer... progress) {
//setProgressPercent(progress[0]);
}
protected void onPostExecute(Bitmap result) {
Drawable dr = new BitmapDrawable(context.getResources(), result);
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
//Methods for version <16 (JELLY_BEAN 4.1)
imgContainer.setBackgroundDrawable(dr);
} else {
// Methods for version >=16 (JELLY_BEAN 4.1)
imgContainer.setBackground(dr);
}
}
}
logcat的
06-29 16:02:05.435 2125-2143/com.bis.org.auInsight W/dalvikvm﹕ threadid=13: thread exiting with uncaught exception (group=0xb5fe8180)
06-29 16:02:05.435 2125-2143/com.bis.org.auInsight E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #2
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:278)
at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
at java.util.concurrent.FutureTask.run(FutureTask.java:137)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
at java.lang.Thread.run(Thread.java:856)
Caused by: java.lang.OutOfMemoryError
at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:493)
at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:549)
at com.bis.org.auInsight.interest.Interest_Adapter$downloadImageTask.doInBackground(Interest_Adapter.java:256)
at com.bis.org.auInsight.interest.Interest_Adapter$downloadImageTask.doInBackground(Interest_Adapter.java:236)
at android.os.AsyncTask$2.call(AsyncTask.java:264)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
at java.util.concurrent.FutureTask.run(FutureTask.java:137)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
at java.lang.Thread.run(Thread.java:856)
06-29 16:02:05.594 2125-2144/com.bis.org.auInsight I/dalvikvm-heap﹕ Clamp target GC heap from 16.347MB to 16.000MB
06-29 16:02:05.594 2125-2144/com.bis.org.auInsight D/dalvikvm﹕ GC_FOR_ALLOC freed 78K, 2% free 14636K/14855K, paused 6ms
06-29 16:02:05.594 2125-2144/com.bis.org.auInsight I/dalvikvm-heap﹕ Forcing collection of SoftReferences for 6000012-byte allocation
06-29 16:02:05.604 2125-2144/com.bis.org.auInsight I/dalvikvm-heap﹕ Clamp target GC heap from 16.346MB to 16.000MB
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight D/dalvikvm﹕ GC_BEFORE_OOM freed <1K, 2% free 14635K/14855K, paused 20ms
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight E/dalvikvm-heap﹕ Out of memory on a 6000012-byte allocation.
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ "AsyncTask #3" prio=5 tid=14 RUNNABLE
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ | group="main" sCount=0 dsCount=0 obj=0xb6695790 self=0x91c30b8
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ | sysTid=2144 nice=10 sched=3/0 cgrp=[fopen-error:2] handle=153307736
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ | schedstat=( 0 0 0 ) utm=1 stm=0 core=0
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:493)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:549)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at com.bis.org.auInsight.interest.Interest_Adapter$downloadImageTask.doInBackground(Interest_Adapter.java:256)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at com.bis.org.auInsight.interest.Interest_Adapter$downloadImageTask.doInBackground(Interest_Adapter.java:236)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at android.os.AsyncTask$2.call(AsyncTask.java:264)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at java.util.concurrent.FutureTask.run(FutureTask.java:137)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ at java.lang.Thread.run(Thread.java:856)
06-29 16:02:05.614 2125-2144/com.bis.org.auInsight I/dalvikvm﹕ [ 06-29 16:02:05.614 2125:0x860 D/skia ]
答案 0 :(得分：0)
BitmapFactory可以为图像分配RAM。为您下载的每个图像生成单独的AsyncTask可能更好。特别是因为您目前只返回Bitmap中的一个AsyncTask，因此整个循环无效。
为了提高性能，您还可以将图像缩放到较小的尺寸，但要注意不要损失太多的质量：
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 2;
getBitmap = BitmapFactory.decodeStream(input, null, options);
答案 1 :(得分：0)
您检索的图像太大，这意味着它会在您的堆中占用太多空间并导致堆溢出，因此应用程序崩溃，而您可以使用ImageLoader下载图像，然后您将拥有能够控制下载的图像大小，压缩率，分辨率，内存消耗和许多其他选项：
DisplayImageOptions options = new DisplayImageOptions.Builder()
.bitmapConfig(Bitmap.Config.ALPHA_8)
.imageScaleType(ImageScaleType.IN_SAMPLE_INT).build();
ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(
ISolaceContext.getAppContext())
.discCacheExtraOptions(20, 20, CompressFormat.JPEG, 100, null)
.defaultDisplayImageOptions(options).build();
ImageLoader.getInstance().init(config);
ImageLoader loader = ImageLoader.getInstance();
loader.loadImage(url, new SimpleImageLoadingListener() {
@Override
public void onLoadingComplete(String imageUri, View view,
Bitmap loadedImage) {
// Now you have the image in your hands as a Bitmap(called: loadedImage) and Now you can do whatever you want with it
stream.close();
stream = null;
}
});
loader.clearDiscCache();
loader.clearMemoryCache();
答案 2 :(得分：0)
当列表中有多个图像时，滚动后的内存会变得很富有。现在无法分配内存，而且您的方法不会回收先前映像占用的内存，＆amp;它只能在巨大的RAM可用时运行。尝试使用Univesal-Image-Loader使用LruCache进行内存管理，＆amp;尝试运行此示例＆amp;修改你的代码！