我正在使用GridView来显示图像。图像从源下载并添加到BitmapCache。 GridView位于ViewFlipper（其中有一个ListView作为第二个View）中。我第一次使用GridView，但是当我使用ListView时，我曾多次使用Adapters。
目前，Feed仅提供两张图片。但是，当我启动包含GridView的Fragment时，我得到一个OutOfMemoryError导致bei BitmapFactory.decodeStream（）。当我深入研究logcat时，我注意到我的适配器里面的GridView的getView（）被多次调用。 我知道如果多次调用getView（）并没有什么特别之处，但我的适配器中的getView（） - 方法仅在位置0被调用超过120次。我真的不明白为什么它经常被调用。但我很确定这会导致我的内存问题，因为此方法会在几秒钟内尝试加载位图超过100次。
由于我已经尝试使用ViewHolder回收我的视图，我现在很无奈，我希望有人能解释一下getView（）的大量调用和/或可能会给我一个提示来解决我的问题
getView（） - 我的适配器的方法：
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null) {
holder = new ViewHolder();
convertView = inflater.inflate(R.layout.pictures_grid_item, parent, false);
holder.image = (ImageView) convertView.findViewById(R.id.picturesGridImage);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
holder.image.setImageBitmap(null);
}
Picture picture = (Picture) pictureList.get(position);
String imageUrl = picture.getUrl();
if (!TextUtils.isEmpty(imageUrl)) {
holder.image.setTag(imageUrl);
ImageLoader.getInstance(context).loadImageWithTagCheck(holder.image);
}
return convertView;
}
private static class ViewHolder {
ImageView image;
}
loadImageWithTagCheck（） -method只是检查图像是否已经下载（应该是这种情况）
包含视图的片段：
public class PicturesFragment extends BaseFragment {
private List<Parcelable> pictureList;
private PicturesGridAdapter adapter;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.pictures_fragment, container, false);
// TODO: Remove final after development
final MediaActivity activity = (MediaActivity) getActivity();
pictureList = activity.getPictures();
adapter = new PicturesGridAdapter(activity, pictureList);
GridView gridview = (GridView) view.findViewById(R.id.picturesGrid);
gridview.setAdapter(adapter);
gridview.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
Toast.makeText(activity, "" + position, Toast.LENGTH_SHORT).show();
}
});
return view;
}
}
BTW：我没有在任何地方使用* wrap_content *。
编辑： 这是图像加载器的代码。当然，ImageLoader是导致outOfMemoryError的问题。但我认为问题恰恰与适配器有关，因为在创建视图之后，对位置0的120个getView（）调用可能不对。并且适配器只创建一次，因此在我的适配器的单个实例中进行了> 120次调用。 （这是一个非常庞大而复杂的项目，所以“简单”的图像加载器有很多代码）
public void loadImageWithTagCheck(final ImageView view) {
final String url = (String) view.getTag();
final Handler uiHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
}
};
if (imageHandler != null) {
imageHandler.post(new Runnable() {
@Override
public void run() {
final Bitmap bmp = getImage(url, view);
uiHandler.post(new Runnable() {
@Override
public void run() {
String tagUrl = (String) view.getTag();
if (tagUrl.equals(url) && bmp != null
&& !bmp.isRecycled()) {
scaleBitmapAndAdjustViewByHeight(view, bmp);
} else if (bmp != null) {
bmp.recycle();
}
}
});
}
});
}
}
private Bitmap getImage(String url, View v) {
Bitmap bmp = null;
if (url != null && !TextUtils.isEmpty(url)) {
String md5Url = Utility.md5(url);
if (cache.containsKey(md5Url)) {
bmp = cache.getBitmap(md5Url);
} else {
HttpGet httpGet = new HttpGet();
HttpClient httpClient = new DefaultHttpClient();
HttpResponse response = null;
try {
URI uri = new URI(url);
httpGet.setURI(uri);
response = httpClient.execute(httpGet);
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
HttpEntity entity = response.getEntity();
if (entity != null) {
final BufferedInputStream buffIn = new BufferedInputStream(
entity.getContent(), Utils.IO_BUFFER_SIZE);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
options.outWidth = v.getWidth();
options.outHeight = v.getHeight();
options.inPurgeable = true;
options.inInputShareable = true;
options.inPreferredConfig = Bitmap.Config.RGB_565;
bmp = BitmapFactory.decodeStream(buffIn, null,
options);
}
}
} catch (URISyntaxException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
}
if (bmp != null) {
cache.put(md5Url, bmp);
}
}
}
return bmp;
}
private void scaleBitmapAndAdjustViewByHeight(final ImageView view,
final Bitmap bmp) {
ViewTreeObserver vto = view.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@SuppressLint("NewApi")
@SuppressWarnings("deprecation")
@Override
public void onGlobalLayout() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
view.getViewTreeObserver().removeOnGlobalLayoutListener(
this);
} else {
view.getViewTreeObserver().removeGlobalOnLayoutListener(
this);
}
// Get current dimensions
int width = bmp.getWidth();
int height = bmp.getHeight();
// Determine how much to scale: the dimension requiring less
// scaling is closer to the its side. This way the image always
// stays inside your bounding box AND either x/y axis touches
// it.
int imageViewHeightFromXMLinPixels = view.getHeight();
float xScale = (float) ((imageViewHeightFromXMLinPixels * 2.75) / width);
float yScale = ((float) imageViewHeightFromXMLinPixels)
/ height;
float scale = (xScale <= yScale) ? xScale : yScale;
// Create a matrix for the scaling and add the scaling data
Matrix matrix = new Matrix();
matrix.postScale(scale, scale);
// Create a new bitmap
Bitmap scaledBitmap = Bitmap.createBitmap(bmp, 0, 0, width,
height, matrix, true);
width = scaledBitmap.getWidth(); // re-use
view.setImageBitmap(scaledBitmap);
view.getLayoutParams().width = width;
}
});
view.requestLayout();
}
答案 0 :(得分：2)
摆脱scaleBitmapAndAdjustViewByHeight(...)方法。
相反，做一个简单的view.setImageBitmap(bmp)。
为什么呢？
scaleBitmapAndAdjustViewByHeight(...)调用view.requestLayout()，这可能导致调用适配器getView(...)并以死锁结束，最后是OutOfMemoryError。