I guess the problem is not in your layout; the problem is somewhere else in your code. And you are probably leaking context somewhere.
Other probable reason is that you must be creating bulky multiple objects while parsing your XML (as you mentioned this occurs the first time when you parse XML). Though Java has auto garbage collection approach, but still you can not completely rely on it. It is a good practice to nullify your collection instance or clear your objects content when you don't need them any more.
But still I have prepared a list of important points which you should remember while dealing with bitmaps on Android.
1) You can call recycle on each bitmap and set them to null. (bitmap.recycle() will release all the memory used by this bitmap, but it does not nullify the bitmap object).
2) You can also unbind the drawables associated with layouts when an activity is destroyed. Try the code given below and also have a look at this link link.
private void unbindDrawables(View view) {
if (view.getBackground() != null) {
view.getBackground().setCallback(null);
}
if (view instanceof ViewGroup) {
for (int i = 0; i < ((ViewGroup) view).getChildCount(); i++) {
unbindDrawables(((ViewGroup) view).getChildAt(i));
}
((ViewGroup) view).removeAllViews();
}
}
// Call this method from onDestroy()
void onDestroy() {
super.onDestroy();
unbindDrawables(findViewById(R.id.RootView));
System.gc();
}
3) You can convert your hashmaps to WeakHashmaps, so that its memory would get released when the system runs low on memory.
4) You can scale/resize all your bitmaps. To scale bitmaps you can try something like this:
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 8;
Bitmap preview_bitmap=BitmapFactory.decodeStream(is, null, options);
This inSampleSize option reduces memory consumption.
Here's a complete method. First it reads the image size without decoding the content itself. Then it finds the best inSampleSize value; it should be a power of 2. And finally the image is decoded.
// 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;
BitmapFactory.decodeStream(new FileInputStream(f),null,o);
// The new size we want to scale to
final int REQUIRED_SIZE=70;
// Find the correct scale value. It should be the power of 2.
int scale=1;
while(o.outWidth/scale/2 >= REQUIRED_SIZE && o.outHeight/scale/2 >= REQUIRED_SIZE)
scale*=2;
// Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
}
catch (FileNotFoundException e) {
}
return null;
}
Have a look at this link..
5) You can override onLowMemory() method in an activity which gets a call when entire system runs low on memory. You can release a few resources there.
6) You can make your objects SoftReference or Weakreference, so that they get released in a low-memory condition.
A very common memory leak that I observed is due to the implementation of inner classes and implementing Handler in Activity. This links talks about the same in more detail.
I hope this helps to eliminate your problem.
