android - what is the use of recycle() method in TypedArray

Question

I have created a GalleryView and ImageView which displays the Image bigger when an item is clicked in the gallery. I have used the below code to implement the ImageAdapter:

public ImageAdapter(Context c)
{
    context = c;
    TypedArray a = obtainStyledAttributes(R.styleable.gallery1);
    itemBackground = a.getResourceId(R.styleable.gallery1_android_galleryItemBackground, 0);    
    a.recycle();    
}

When I removed the statement a.recycle() there is no change and the app is running normally as before, but everywhere I read that it is compulsory to recycle the typedArray. When there is no change in the way my app is running what is the use of the recycle() method?

Answer 1

The point is similar to the idea of clearing a pointer in a C-language (if you're familiar with that). It is used to make the data associated with a ready for garbage collection so memory/data is not inefficiently bound to a when it doesn't need to be. Read more here.

It's important to note that this isn't really necessary unless you're actually reusing "a". GC should automatically clear up this data for you if the object is not used again. The reason why a TypedArray is different, however, is because a TypedArray has other internal data that must be returned (known as StyledAttributes) to the TypedArray for later reuse. Read about that here.