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複数のアクティビティを再読み込みした後に問題が発生しました。メモリ不足例外が発生し、アプリがクラッシュしました。開発者のGoogleドキュメントの例を使用して、私はそれを行っていますが、私は、複数のビットマップを持って考慮し、ここでは外部のクラスから複数のリロード後にAndroid out of memoryエラーが発生する
をビットマップを呼び出して、これを行うためには、私のロードマップクラスは
public class bitmapHTTP{
Context ctx;
private LruCache<String, Bitmap> mMemoryCache;
int iv;
public bitmapHTTP(Context c){
ctx = c;
final int maxMemory = (int) (Runtime.getRuntime().maxMemory()/1024);
final int cacheSize = maxMemory/8;
mMemoryCache = new LruCache<String, Bitmap>(cacheSize) {
@Override
protected int sizeOf(String key, Bitmap bitmap) {
// The cache size will be measured in kilobytes rather than
// number of items.
return bitmap.getByteCount()/1024;
}
};
}
public void addBitmapToMemoryCache(String key, Bitmap bitmap) {
if(getBitmapFromMemCache(key) == null) {
mMemoryCache.put(key, bitmap);
}
}
public Bitmap getBitmapFromMemCache(String key) {
return mMemoryCache.get(key);
}
public void loadBitmap(String resId, ImageView imageView) {
final String imageKey = String.valueOf(resId);
iv = imageView.getWidth();
Bitmap bitmap = getBitmapFromMemCache(imageKey);
if(bitmap != null) {
imageView.setImageBitmap(bitmap);
}else{
if(cancelPotentialWork(imageKey, imageView)){
Bitmap loading = decodeSampledBitmapFromResource(ctx.getResources(), R.drawable.whiteseetrough, imageView.getWidth(), imageView.getWidth());
BitmapWorkerTask task = new BitmapWorkerTask(imageView);
AsyncDrawable asyncDrawable = new AsyncDrawable(ctx.getResources(), loading, task);
imageView.setImageDrawable(asyncDrawable);
task.execute(resId);
}
}
}
public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height/2;
final int halfWidth = width/2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight/inSampleSize) > reqHeight
&& (halfWidth/inSampleSize) > reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
public static Bitmap decodeSampledBitmapFromResource(Resources res, int resId, int reqWidth, int reqHeight) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeResource(res, resId, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeResource(res, resId, options);
}
class BitmapWorkerTask extends AsyncTask<String, Void, Bitmap> {
private final WeakReference<ImageView> imageViewReference;
private String data = null;
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(String... params) {
data = params[0];
final BitmapFactory.Options options = new BitmapFactory.Options();
Bitmap bitmap;
if(data.equals("null")){
bitmap = decodeSampledBitmapFromResource(ctx.getResources(), R.drawable.whiteseetrough, iv, iv);
addBitmapToMemoryCache(String.valueOf(params[0]), bitmap);
return bitmap;
}else{
bitmap = getBitmapFromMemCache(data);
if(bitmap == null){
// Process as normal
try {
URL url = new URL(data);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
options.inSampleSize = calculateInSampleSize(options, iv, iv);
options.inJustDecodeBounds = false;
bitmap = BitmapFactory.decodeStream(input, null, options);
addBitmapToMemoryCache(String.valueOf(params[0]), bitmap);
return bitmap;
}catch(IOException e){
e.printStackTrace();
return null;
}
}
}
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 && bitmap != null) {
final ImageView imageView = imageViewReference.get();
final BitmapWorkerTask bitmapWorkerTask =
getBitmapWorkerTask(imageView);
if (this == bitmapWorkerTask && imageView != null) {
imageView.setImageBitmap(bitmap);
}
}
}
}
static class AsyncDrawable extends BitmapDrawable {
private final WeakReference<BitmapWorkerTask> bitmapWorkerTaskReference;
public AsyncDrawable(Resources res, Bitmap bitmap,
BitmapWorkerTask bitmapWorkerTask) {
super(res, bitmap);
bitmapWorkerTaskReference =
new WeakReference<BitmapWorkerTask>(bitmapWorkerTask);
}
public BitmapWorkerTask getBitmapWorkerTask() {
return bitmapWorkerTaskReference.get();
}
}
public static boolean cancelPotentialWork(String data, ImageView imageView) {
final BitmapWorkerTask bitmapWorkerTask = getBitmapWorkerTask(imageView);
if (bitmapWorkerTask != null) {
final String bitmapData = bitmapWorkerTask.data;
// If bitmapData is not yet set or it differs from the new data
if(bitmapData == null || bitmapData != data) {
// Cancel previous task
bitmapWorkerTask.cancel(true);
} else {
// The same work is already in progress
return false;
}
}
// No task associated with the ImageView, or an existing task was cancelled
return true;
}
private static BitmapWorkerTask getBitmapWorkerTask(ImageView imageView) {
if (imageView != null) {
final Drawable drawable = imageView.getDrawable();
if (drawable instanceof AsyncDrawable) {
final AsyncDrawable asyncDrawable = (AsyncDrawable) drawable;
return asyncDrawable.getBitmapWorkerTask();
}
}
return null;
}
}
これは、ビットマップをimageViewにロードする方法です。
私は、どこかでメモリリークがあると思います。 – Vyacheslav
私のこの古い回答を確認してください。まだ適用されており、依然として非常に有効です。http://stackoverflow.com/questions/31162558/loading-images-in-a-gridview -from-server-android/31162942＃31162942 – Budius