Releasing a bitmap attached to an ImageView

问题

I have a basic activity (SherlockActivity subclass), and the view it loads has a single, max-sized ImageView.

<LinearLayout xmlns:p1="http://schemas.android.com/apk/res/android"
    p1:orientation="vertical"
    p1:minWidth="25px"
    p1:minHeight="25px"
    p1:layout_width="fill_parent"
    p1:layout_height="fill_parent"
    p1:id="@+id/linearLayout1">
    <ImageView
        p1:src="@android:drawable/ic_menu_gallery"
        p1:layout_width="fill_parent"
        p1:layout_height="fill_parent"
        p1:id="@+id/imageView"
        p1:scaleType="fitCenter" />
</LinearLayout>

The only thing the Activity does is load a Bitmap and assign it to the ImageView

var iv = FindViewById<ImageView>(Resource.Id.imageView);
iv.SetBitmapImage(BitmapFactory.decodeFile(file....))

Before I worked out how to resize bitmaps on load ( http://developer.android.com/training/displaying-bitmaps/load-bitmap.html ) this was chewing up 5MB of memory each time I loaded the activity, until the app crashed (now it doesn't, but I think this problem is still there). Even if I did it like this:

In parent activity, tap button to open child
In child (the above image view) tap back
In parent, open child
In child, tap back
etc etc. until it crashes (about 4 times around, as it's 5MB each time!)

SO THE ACTUAL QUESTION: Am I expected to dispose of the image when the Activity stops or is destroyed? I thought in Java - or C# - things are GC'ed, so I don't need to do it. Am I missing something in the Activity lifecycle?

Both answer authors eventually came up with the right answer (the GC does it, but you can force it with recycle(). So marking correct the one which had it in the answer, so it's easier to find for others

回答1:

Try calling recycle() on the bitmap.

http://developer.android.com/reference/android/graphics/Bitmap.html#recycle%28%29

回答2:

Loading large bitmaps can cause OutOfMemoryError. You can scale down the image before loading it in your app; that will consume less memory. You may look here: https://stackoverflow.com/a/13011614/1117338

来源：https://stackoverflow.com/questions/13027209/releasing-a-bitmap-attached-to-an-imageview

标签

android

xamarin.android