在我的 ListView 中只有一个 ImageView 。我正在尝试在 asynctask 中在此 ListView 中加载图像，并且我正在使用可绘制资源，但它会产生许多错误，我无法解决。 这些是错误。
09-11 22:25:00.904: E/dalvikvm-heap(1165): Out of memory on a 3318016-byte allocation.
09-11 22:25:01.664: E/AndroidRuntime(1165): FATAL EXCEPTION: AsyncTask #1
09-11 22:25:01.664: E/AndroidRuntime(1165): java.lang.RuntimeException: An error occured while executing doInBackground()
09-11 22:25:01.664: E/AndroidRuntime(1165): at android.os.AsyncTask$3.done(AsyncTask.java:278)
09-11 22:25:01.664: E/AndroidRuntime(1165): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
09-11 22:25:01.664: E/AndroidRuntime(1165): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
09-11 22:25:01.664: E/AndroidRuntime(1165): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
09-11 22:25:01.664: E/AndroidRuntime(1165): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
09-11 22:25:01.664: E/AndroidRuntime(1165): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
09-11 22:25:01.664: E/AndroidRuntime(1165): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
09-11 22:25:01.664: E/AndroidRuntime(1165): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
09-11 22:25:01.664: E/AndroidRuntime(1165): at java.lang.Thread.run(Thread.java:856)
09-11 22:25:01.664: E/AndroidRuntime(1165): Caused by: java.lang.OutOfMemoryError
09-11 22:25:01.664: E/AndroidRuntime(1165): at android.graphics.BitmapFactory.nativeDecodeAsset(Native Method)
09-11 22:25:01.664: E/AndroidRuntime(1165): at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:483)
09-11 22:25:01.664: E/AndroidRuntime(1165): at android.graphics.BitmapFactory.decodeResourceStream(BitmapFactory.java:351)
09-11 22:25:01.664: E/AndroidRuntime(1165): at android.graphics.BitmapFactory.decodeResource(BitmapFactory.java:374)
09-11 22:25:01.664: E/AndroidRuntime(1165): at android.graphics.BitmapFactory.decodeResource(BitmapFactory.java:404)
09-11 22:25:01.664: E/AndroidRuntime(1165): at com.example.exampleimages.MyAdapter$BitmapWorkerTask.doInBackground(MyAdapter.java:92)
09-11 22:25:01.664: E/AndroidRuntime(1165): at com.example.exampleimages.MyAdapter$BitmapWorkerTask.doInBackground(MyAdapter.java:1)
09-11 22:25:01.664: E/AndroidRuntime(1165): at android.os.AsyncTask$2.call(AsyncTask.java:264)
09-11 22:25:01.664: E/AndroidRuntime(1165): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
09-11 22:25:01.664: E/AndroidRuntime(1165): ... 5 more
这是我的 ListView 自定义适配器，AsyncTask 类在这个适配器中
class MyAdapter extends BaseAdapter {
public Context context;
private int[] images;
public MyAdapter(Context context, int[] images) {
this.context = context;
this.images = images;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return images.length;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return images[position];
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
public static class MyViewHolder {
ImageView imageView;
public MyViewHolder(View v) {
// TODO Auto-generated constructor stub
imageView = (ImageView) v.findViewById(R.id.imgView);
}
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
View row = convertView;
MyViewHolder holder = null;
if (row == null) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row = inflater.inflate(R.layout.custom_list, parent, false);
holder = new MyViewHolder(row);
row.setTag(holder);
} else {
holder = (MyViewHolder) row.getTag();
}
// ImageView imageView = (ImageView) row.findViewById(R.id.imgView);
if (holder.imageView != null) {
new BitmapWorkerTask(holder.imageView).execute(images[position]);
}
//row = convertView;
//holder.imageView.setImageResource(images[position]);
//holder.imageView.setImageResource(R.drawable.samplenew003);
return row;
}
class BitmapWorkerTask extends AsyncTask<Integer, Void, Bitmap> {
private final WeakReference<ImageView> imageViewReference;
private int data = 0;
public BitmapWorkerTask(ImageView imageView) {
// Use a WeakReference to ensure the ImageView can be garbage
// collected
imageViewReference = new WeakReference<ImageView>(imageView);
}
// Decode image in background.
@Override
protected Bitmap doInBackground(Integer... params) {
data = params[0];
// return decodeSampledBitmapFromResource(context.getResources(),
// data, 100, 100);
Bitmap bitmap = BitmapFactory.decodeResource(
context.getResources(), data);
// Bitmap bitmap = Bitmap.createScaledBitmap(BitmapFactory
// .decodeResource(context.getResources(), data), 750 , 1106, true);
bitmap.compress(Bitmap.CompressFormat.PNG, 0, null); // compress
// Bitmap bitmap =
// BitmapBitmapFact.decodeResource(context.getResources(), data,
// true);
// bitmap.compress(Bitmap.CompressFormat.PNG, 90);
return bitmap;
}
// Once complete, see if ImageView is still around and set bitmap.
@Override
protected void onPostExecute(Bitmap bitmap) {
if (isCancelled()) {
bitmap = null;
}
if (imageViewReference != null) {
ImageView imageView = imageViewReference.get();
if (bitmap != null) {
// final ImageView imageView = imageViewReference.get();
imageView.setImageBitmap(bitmap);
} else {
imageView.setImageDrawable(imageView.getContext()
.getResources()
.getDrawable(R.drawable.samplenew003));
}
}
}
}
}
这是我的主要 Activity
public class MainActivity extends ActionBarActivity {
private ListView listView;
private MyAdapter myAdapter;
int[] images = { R.drawable.img001, R.drawable.img002, R.drawable.img003,
R.drawable.img004, R.drawable.img005, R.drawable.img006,
R.drawable.img007, R.drawable.img008, R.drawable.img009,
R.drawable.img010, R.drawable.img011, R.drawable.img012,
R.drawable.img013, R.drawable.img014, R.drawable.img015,
R.drawable.img016, R.drawable.img017, R.drawable.img018,
R.drawable.img019, R.drawable.img020, R.drawable.img021,
R.drawable.img022, R.drawable.img023, R.drawable.img024,
R.drawable.img025, R.drawable.img026, R.drawable.img027,
R.drawable.img028, R.drawable.img029, R.drawable.img030,
R.drawable.img031, R.drawable.img032, R.drawable.img033,
R.drawable.img034, R.drawable.img035, R.drawable.img036,
R.drawable.img037, R.drawable.img038, R.drawable.img039,
R.drawable.img040, R.drawable.img041, R.drawable.img042,
R.drawable.img043, R.drawable.img044, R.drawable.img045,
R.drawable.img046, R.drawable.img047, R.drawable.img048,
R.drawable.img049, R.drawable.img050, R.drawable.img051,
R.drawable.img052, R.drawable.img053, R.drawable.img054,
R.drawable.img055, R.drawable.img056, R.drawable.img057,
R.drawable.img058, R.drawable.img059, R.drawable.img060,
R.drawable.img061, R.drawable.img062, R.drawable.img063,
R.drawable.img064, R.drawable.img065, R.drawable.img066,
R.drawable.img067, R.drawable.img068, R.drawable.img069,
R.drawable.img070, R.drawable.img071, R.drawable.img072,
R.drawable.img073, R.drawable.img074, R.drawable.img075,
R.drawable.img076, R.drawable.img077, R.drawable.img078,
R.drawable.img079, R.drawable.img080, R.drawable.img081,
R.drawable.img082, R.drawable.img083, R.drawable.img084,
R.drawable.img085, R.drawable.img086, R.drawable.img087,
R.drawable.img088, R.drawable.img089, R.drawable.img090,
R.drawable.img091, R.drawable.img092, R.drawable.img093,
R.drawable.img094, R.drawable.img095, R.drawable.img096,
R.drawable.img097, R.drawable.img098, R.drawable.img099,
R.drawable.img100, R.drawable.img101, R.drawable.img102,
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myAdapter = new MyAdapter(this, images);
listView = (ListView) findViewById(R.id.imgList);
listView.setAdapter(myAdapter);
}
最佳答案
问题是Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), data);
您的图像太大，这就是您 3318016 字节分配内存不足的原因。
对于 bitmap.compress(Bitmap.CompressFormat.PNG, 0, null); 这里 0 表示图像质量尝试 80 或 90
此外，请记住 getView() 每个位置可以调用 3-4 次。这意味着在您的异步完成之前，有 2-3 个 View 很可能会变得无效。您需要确保您正在适本地监视空值。此外，您错误地跟踪了哪些数据 int 与每个 View 相关。检查此项将有助于减少创建位图的次数，这可能会减少内存不足错误。这是调整后的代码:
class BitmapWorkerTask extends AsyncTask<Void, Void, Bitmap> {
private final WeakReference<ImageView> imageViewReference;
private int data = 0;
public BitmapWorkerTask(ImageView imageView, int data) {
//Used later to ensure imageview is the correct view for the data
imageView.setTag(data);
// Use a WeakReference to ensure the ImageView can be garbage collected
imageViewReference = new WeakReference<ImageView>(imageView);
}
// Decode image in background.
@Override
protected Bitmap doInBackground(Void... params) {
ImageView iv = imageViewReference.get();
if (iv == null) return null;
Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), data);
if (bitmap != null) {
bitmap.compress(Bitmap.CompressFormat.PNG, 0, null); // compress
} else {
//Load your default image here instead and return it instead
}
return bitmap;
}
// Once complete, see if ImageView is still around and set bitmap.
@Override
protected void onPostExecute(Bitmap bitmap) {
if (isCancelled() || bitmap == null) {
return;
}
ImageView imageView = imageViewReference.get();
if (imageView != null) {
int viewData = (Integer) imageView.getTag();
if (viewData.equals(data)) { //Make sure our view reference still represents that data we originally started with (This happens due to view recycling)
imageView.setImageBitmap(bitmap);
}
}
}
}
据我所知，您需要针对何时加载默认图形提出不同的解决方案。
关于android - 无法使用 AsyncTask 在 ListView 中加载图像，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25793984/